Business Acquisition [Axis] Business Acquisition [Axis] Increase (Decrease) in Unbilled Contract Receivable Increase (Decrease) in Unbilled Contract Receivable Increase (Decrease) in Unbilled Contract Receivable Covance Drug Development [Member] Covance Drug Development [Member] Covance Drug Development [Member] Restatement [Axis] Revision of Prior Period [Axis] Net earnings Net earnings Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Entity Address, Postal Zip Code Entity Address, Postal Zip Code Per Share Amount [Abstract] Per Share Amount [Abstract] Commons Stock Issued During Period Shares Employee Stock Plans Commons Stock Issued During Period Shares Employee Stock Plans Number of common shares issued during the period as a result of an employee stock purchase plan and/or stock option plan. Notes Receivable [Member] Notes Receivable [Member] Preferred Stock, Shares Outstanding Preferred Stock, Shares Outstanding Debt Instrument [Axis] Debt Instrument [Axis] Segment Reconciliation of Operating Income to Consolidated [Abstract] Segment Reconciliation of Operating Income to Consolidated [Abstract] Segment Reconciliation of Operating Income to Consolidated [Abstract] Line of Credit Facility, Maximum Borrowing Capacity Revolving Credit Facility, maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Loss Contingency, Damages Awarded, Value Loss Contingency, Damages Awarded, Value Debt Conversion [Table] Debt Conversion [Table] Surrender of restricted stock and performance share awards Stock Issued During Period, Value, Restricted Stock Award, Forfeitures Contract with Customer, Performance Obligation Satisfied in Previous Period Contract with Customer, Performance Obligation Satisfied in Previous Period Fair Value Hedge Liabilities Fair Value Hedge Liabilities Contingent Consideration Classified as Equity, Fair Value Disclosure Contingent Consideration Classified as Equity, Fair Value Disclosure Statistical Measurement [Domain] Statistical Measurement [Domain] Indefinite-lived Intangible Assets, Major Class Name [Domain] Indefinite-Lived Intangible Assets, Major Class Name [Domain] Interest Interest Paid In Cash The amount of cash paid during the current period for interest owed on money borrowed Short-term Debt, Type [Axis] Short-Term Debt, Type [Axis] Other comprehensive income before reclassifications Other comprehensive income before reclassifications Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss), before Reclassification and Tax Additional paid-in capital Additional Paid in Capital, Common Stock Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles Accounts Receivable, before Allowance for Credit Loss Accounts Receivable, before Allowance for Credit Loss Foreign Currency Contracts, Liability, Fair Value Disclosure Foreign Currency Contracts, Liability, Fair Value Disclosure Third party [Member] Third party [Member] Third party [Member] Net Income (Loss) Attributable to Parent Net earnings attributable to Laboratory Corporation of America Holdings Net earnings attributable to Laboratory Corporation of America Holdings Net Income (Loss) Attributable to Parent Stock options (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount LabCorp Diagnostics [Member] LabCorp Diagnostics [Member] LabCorp Diagnostics [Member] Cumulative Effect, Period of Adoption [Axis] Cumulative Effect, Period of Adoption [Axis] Document Information [Table] Document Information [Line Items] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Equity Component [Domain] Equity Component [Domain] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Scenario [Axis] Scenario [Axis] 1.55% senior notes due 2026 1.55% senior notes due 2026 1.55% senior notes due 2026 Allowance for Credit Loss Allowance for Credit Loss Allowance for Credit Loss Diagnostics Diagnostics [Member] Diagnostics [Member] Investment, Name [Domain] Investment, Name [Domain] Long term debt issuance costs Long term debt issuance costs Long term debt issuance costs Foreign Currency Translation Adjustments, Beginning balance Foreign Currency Translation Adjustments, Ending balance Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax Net Benefit Plan Adjustments, Beginning balance Net Benefit Plan Adjustments, Ending balance Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax Supplemental Cash Flow Elements [Abstract] Cash Surrender Value, Fair Value Disclosure Cash Surrender Value, Fair Value Disclosure Supplemental Cash Flow Information [Abstract] Supplemental Cash Flow Information [Abstract] Capitalized Contract Cost, Net Capitalized Contract Cost, Net Fair Value Hedges, Net Fair Value Hedges, Net Goodwill [Line Items] Goodwill [Line Items] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Fair Value Liabilities Measured On Recurring Basis Deferred Compensation Liability Fair Value Liabilities Measured On Recurring Basis Deferred Compensation Liability Fair Value Liabilities Measured On Recurring Basis Deferred Compensation Liability Entity Address, State or Province Entity Address, State or Province Level 1 [Member] Fair Value, Inputs, Level 1 [Member] Other Comprehensive Earnings, Net of Tax Other Comprehensive Income (Loss), Net of Tax [Abstract] Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax Accrued Sales Commission Accrued Sales Commission Operating Lease, Liability, Current Operating Lease, Liability, Current Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Contract with Customer, Basis of Pricing [Axis] Contract with Customer, Basis of Pricing [Axis] Lender Name [Axis] Lender Name [Axis] Issuance of common stock under employee stock plans Issuance of common stock under employee plans Aggregate change in value for stock issued in period under ESPP combined with the value of stock issued as a result of option exercises. Liability Class [Axis] Liability Class [Axis] Patents, Licenses And Technology [Member] Patents, Licenses And Technology [Member] Patents are the exclusive legal right granted by the government to the owner of the patent to exploit an invention or a process for a period of time specified by law. Licenses are rights, generally of limited duration, under a license arrangement (for example, to sell or otherwise utilize specified products or processes in a specified territory). Technology-based intangible assets are innovations or scientific advances that have not been patented. Legal Entity [Axis] Legal Entity [Axis] Credit Facility Option to Increase Credit Facility Option to Increase Credit Facility Option to Increase Long-term Debt, Excluding Current Maturities Long-Term Debt, Excluding Current Maturities Fair market value of senior notes Senior Notes Fair Value Estimated fair value of the debt instrument (senior notes) at the balance-sheet date Noncontrolling interest Liabilities Geographical [Axis] Geographical [Axis] CASH FLOWS FROM INVESTING ACTIVITIES: Net Cash Provided by (Used in) Investing Activities [Abstract] Note Receivable, Allowance for Credit Loss Note Receivable, Allowance for Credit Loss Note Receivable, Allowance for Credit Loss Technology-Based Intangible Assets [Member] Technology-Based Intangible Assets [Member] Increase (Decrease) in Accrued Liabilities and Other Operating Liabilities Increase (Decrease) in Accrued Liabilities and Other Operating Liabilities Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Fair Value, Liabilities Measured on Recurring Basis, Disclosure Items [Domain] Fair Value Hierarchy and NAV [Domain] Current Expected Credit Losses Opening Balance Sheet Impact on Retained Earnings Current Expected Credit Losses Opening Balance Sheet Impact on Retained Earnings Current Expected Credit Losses Opening Balance Sheet Impact on Retained Earnings Revolving Credit Facility [Member] Revolving Credit Facility [Member] Noncontrolling Interest Puts [Abstract] Noncontrolling Interest Puts [Abstract] Noncontrolling Interest Puts [Abstract] Depreciation And Amortization Of Leased Assets Depreciation And Amortization Of Leased Assets The amount of depreciation recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation. Also, may include amortization charged against earnings for the periodic recognition of capitalized leases. Document Type Document Type Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Segments [Axis] Segments [Axis] Segments [Axis] Product and Service [Domain] Product and Service [Domain] Entity Shell Company Entity Shell Company Deferred income taxes Deferred Income Tax Expense (Benefit) Increase (Decrease) in Deferred Revenue Increase (Decrease) in Deferred Revenue Client [Member] Client [Member] Client [Member] Consolidation Items [Domain] Consolidation Items [Domain] Subsequent Event [Member] Subsequent Event [Member] Contract with Customer, Asset and Liability [Table Text Block] Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Document Period End Date Document Period End Date Other Financing Cash Flows Other Financing Cash Flows Other Financing Cash Flows Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, before Tax Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, before Tax Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Total assets Assets Debt Disclosure [Abstract] Debt Disclosure [Abstract] Earnings Per Share [Abstract] Earnings Per Share [Abstract] Amortization of Deferred Sales Commissions Amortization of Deferred Sales Commissions Net restructuring and other special charges Net restructuring and other special charges Amount charged against earnings in the period for incurred and estimated costs, excluding asset retirement obligations, associated with exit from or disposal of business activities or restructurings pursuant to a program planned and controlled by management, and materially changes either the scope or manner of conduct of a business undertaken. Also, may include reversals and other adjustments to accrued liabilities and special charges, if any, for asset abandonment, uncollectible balances, etc. Income Statement Location [Axis] Income Statement Location [Axis] Unbilled Contracts Receivable [Member] Unbilled Contracts Receivable [Member] Unbilled Contracts Receivable [Member] 2.30% senior notes due 2024 2.30% senior notes due 2024 2.30% senior notes due 2024 Interest Rate Swap [Member] Interest Rate Swap [Member] Accrued Liabilities, Current Accrued Liabilities, Current Finite-lived Intangible Assets Acquired Finite-Lived Intangible Assets Acquired Net cash provided by (used for) financing activities Net Cash Provided by (Used in) Financing Activities Accounting Policies [Abstract] Accounting Policies [Abstract] Stockholders' Equity Note [Abstract] Stockholders' Equity Note [Abstract] Decrease in Capital Expenditures Incurred but not yet Paid Increase in Capital Expenditures Incurred but not yet Paid Increase in Capital Expenditures Incurred but not yet Paid Financing Receivable, Allowance for Credit Loss [Table Text Block] Financing Receivable, Allowance for Credit Loss [Table Text Block] Shareholders' equity: Shareholders' Equity: Stockholders' Equity Attributable to Parent [Abstract] Cumulative Effect, Period of Adoption [Domain] Cumulative Effect, Period of Adoption [Domain] Segments [Domain] Segments [Domain] Segments [Domain] Schedule of Goodwill [Table] Schedule of Goodwill [Table] Rollforward of common shares issued Common Shares Issued Rollforward [Abstract] Earnings Per Share Earnings Per Share [Text Block] Customer [Axis] Customer [Axis] Other Noncurrent Liabilities [Member] Other Noncurrent Liabilities [Member] Finance Lease, Liability, Noncurrent Finance Lease, Liability, Noncurrent Comprehensive earnings Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Changes in common shares issued and held in treasury Changes In Common Shares Issued And Held In Treasury [Table Text Block] Schedule is used to show the changes in common shares issued and held in treasury by the entity. Gross Profit Gross Profit Gross Profit Entity Registrant Name Entity Registrant Name Self-Pay [Member] Self-Pay [Member] Goodwill and Intangible Assets, Goodwill, Policy Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block] Subsequent Events Subsequent Events [Text Block] Customer Relationships [Member] Customer Relationships [Member] Common stock, 92.8 and 93.5 shares outstanding at March 31, 2013 and December 31, 2012, respectively Noncontrolling Interest Mezzanine Equity Represents contractual value of a noncontrolling interest put (includes underlying noncontrolling interest). In February 2010, the Company completed a transaction to sell the partnership units acquired from the previous noncontrolling interest holder to a new Canadian partner. As a result of this transaction, the Company recorded a component of noncontrolling interest in liabilities and a component in mezzanine equity. This item represents the mezzanine equity component. Entity Address, City or Town Entity Address, City or Town 4.00% senior notes due 2023 4.00% senior notes due 2023 4.00% senior notes due 2023 Common Shares Outstanding Rollforward [Abstract] Common Shares Outstanding Rollforward [Abstract] Other Comprehensive Income Location [Domain] Other Comprehensive Income Location [Domain] Intersegment Eliminations Intersegment Eliminations [Member] Contract with Customer, Sales Channel [Axis] Contract with Customer, Sales Channel [Axis] Earnings before income taxes Earnings before income taxes Income (Loss) from Continuing Operations Before Income Taxes and Noncontrolling Interest Income (Loss) from Continuing Operations Before Income Taxes and Noncontrolling Interest Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Entity Emerging Growth Company Entity Emerging Growth Company Common Stock, Par or Stated Value Per Share Common Stock, Par or Stated Value Per Share Contract with Customer, Basis of Pricing [Domain] Contract with Customer, Basis of Pricing [Domain] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Investment, Name [Axis] Investment, Name [Axis] Fair Value Measurements Fair Value Disclosures [Text Block] Cash paid during period for: Cash Paid During Period For [Abstract] Trading Symbol Trading Symbol Entity File Number Entity File Number Goodwill [Member] Goodwill [Member] Estimated amortization expense, 2015 Finite-Lived Intangible Asset, Expected Amortization, Year Four Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Deferred Revenue, Current Deferred Revenue, Current Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Business Combination Disclosure [Text Block] Business Combination Disclosure [Text Block] Decrease in accounts payable Increase (Decrease) in Accounts Payable Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block] Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block] Subsequent Events [Abstract] Subsequent Events [Abstract] Revenues Revenues Business Acquisition, Pro Forma Net Income (Loss) Business Acquisition, Pro Forma Net Income (Loss) Investment income Investment Income, Net Credit Facility [Domain] Credit Facility [Domain] Dividends Payable, Date of Record Dividends Payable, Date of Record Intangible Assets, Gross (Excluding Goodwill) Intangible Assets, Gross (Excluding Goodwill) Amortization of intangibles and other assets Amortization of intangible assets Amortization of Intangible Assets Amortization of Intangible Assets Changes in Carrying Amount of Goodwill Schedule of Goodwill [Table Text Block] Basic earnings per common share (in dollars per share) Earnings Per Share, Basic Other Comprehensive Income (Loss), Defined Benefit Plan, Settlement and Curtailment Gain (Loss), before Tax Other Comprehensive Income (Loss), Defined Benefit Plan, Settlement and Curtailment Gain (Loss), before Tax Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax Use Rights [Member] Use Rights [Member] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Loss Contingency, Damages Sought, Value Loss Contingency, Damages Sought, Value Indefinite-lived Intangible Assets [Axis] Indefinite-Lived Intangible Assets [Axis] Stockholders' Equity Attributable to Parent BALANCE BALANCE Stockholders' Equity Attributable to Parent Stockholders' Equity Attributable to Parent Prepaid expenses and other Prepaid Expense, Current Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Number of Measurement Funds Available For Participant Election Number of Measurement Funds Available For Participant Election Number of Measurement Funds Available For Participant Election Entity Interactive Data Current Entity Interactive Data Current Noncontrolling Interest [Line Items] Noncontrolling Interest [Line Items] Capitalized Contract Cost, Amortization Capitalized Contract Cost, Amortization Finite-Lived Intangible Assets, Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Other Comprehensive Income Location [Axis] Other Comprehensive Income Location [Axis] Document Information, Document [Axis] Document Information, Document [Axis] Change in assets and liabilities (net of effects of acquisitions): Increase (Decrease) in Operating Capital [Abstract] Estimated amortization expense, 2014 Finite-Lived Intangible Asset, Expected Amortization, Year Three Credit Facility, Maximum Swing Line Borrowings Credit Facility, Maximum Swing Line Borrowings Credit Facility, Maximum Swing Line Borrowings Payments of Dividends Payments of Dividends Retained Earnings [Member] Retained Earnings [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Common Stock [Member] Common Stock [Member] 2.95% senior notes due 2029 2.95% senior notes due 2029 2.95% senior notes due 2029 Class of Stock [Axis] Class of Stock [Axis] Revenue Revenue [Policy Text Block] Statement [Table] Statement [Table] Document [Domain] Document [Domain] Rollforward of common shares held in treasury Common Shares Held In Treasury Rollforward [Abstract] Document Quarterly Report Document Quarterly Report Allowance for Credit Loss, Receivable, Other, Current Allowance for Credit Loss, Receivable, Other, Current Senior notes due 2027 [Member] Senior notes due 2027 [Member] Senior notes due 2027 [Member] Current assets: Current Assets: Assets, Current [Abstract] Operating Lease, Liability, Noncurrent Operating Lease, Liability, Noncurrent Statistical Measurement [Axis] Statistical Measurement [Axis] Other comprehensive earnings (loss) before tax Other Comprehensive Income (Loss), before Tax Line of Credit Facility, Lender [Domain] Line of Credit Facility, Lender [Domain] Accumulated other comprehensive income Retained Earnings (Accumulated Deficit) Retained Earnings (Accumulated Deficit) Other Operating Activities, Cash Flow Statement Other Operating Activities, Cash Flow Statement Impaired Long-Lived Assets Held and Used, Asset Name [Domain] Impaired Long-Lived Assets Held and Used, Asset Name [Domain] Accounts Receivable, after Allowance for Credit Loss, Current Accounts Receivable, after Allowance for Credit Loss, Current Schedule of Finite-Lived Intangible Assets by Major Class [Table] Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Swap, Type [Axis] Swap, Type [Axis] Swap, Type Statement, Equity Components [Axis] Equity Components [Axis] Equity Components [Axis] Scenario [Domain] Scenario [Domain] Timing of Transfer of Good or Service [Axis] Timing of Transfer of Good or Service [Axis] Restatement [Domain] Revision of Prior Period [Domain] Document Fiscal Year Focus Document Fiscal Year Focus CASH FLOWS FROM OPERATING ACTIVITIES: Net Cash Provided by (Used in) Operating Activities [Abstract] Cash Flow Location [Domain] Cash Flow Location [Domain] [Domain] for Cash Flow Location [Axis] Statement [Line Items] Statement [Line Items] Other countries [Member] Other countries [Member] Other countries [Member] Net proceeds from issuance of stock to employees Net proceeds from issuance of stock to employees The cash inflow associated with the amount received from holders exercising their stock options and employees related to shares purchased under the employee stock purchase plan. Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustments Related to Previous Period Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustments Related to Previous Period Variable Rate [Domain] Variable Rate [Domain] Fair Value, Liabilities Measured on Recurring Basis, Disclosure Items [Axis] Fair Value Hierarchy and NAV [Axis] Selling, general and administrative expenses Selling, General and Administrative Expense Loss Contingencies [Table] Loss Contingencies [Table] Accumulated Other Comprehensive Income [Member] AOCI Attributable to Parent [Member] Deferred Revenue, Revenue Recognized Deferred Revenue, Revenue Recognized Medicare and Medicaid [Member] Medicare and Medicaid [Member] Medicare and Medicaid [Member] Document Transition Report Document Transition Report Local Phone Number Local Phone Number Operating Income (Loss) Operating Income (Loss) Operating Income (Loss) Increase in inventories Increase (Decrease) in Inventories Other acquirees Other acquirees [Member] Other acquirees [Member] Increase (Decrease) in Prepaid Expense and Other Assets Increase (Decrease) in Prepaid Expense and Other Assets Document Information [Table] Document Information [Table] Common stock, shares outstanding (in shares) Common shares outstanding, beginning balance (in shares) Common shares outstanding, ending balance (in shares) Common Stock, Shares, Outstanding Current debt excluding finance lease liability Current debt excluding finance lease liability Current debt excluding finance lease liability Joint venture partnerships and equity method investments Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures Goodwill, net Balance as of January 1 Balance at end of period Goodwill Goodwill Asset Impairment Charges Goodwill and Intangible Asset Impairment Goodwill and Intangible Asset Impairment Long Term Contracts Duration Maximum Long Term Contracts Duration Maximum Long Term Contracts Duration Maximum Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax Adjustments to reconcile net earnings to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Provision for income taxes Income Tax Expense (Benefit) Geographical [Domain] Geographical [Domain] Preferred Stock, Par or Stated Value Per Share Preferred Stock, Par or Stated Value Per Share Income Statement [Abstract] Income Statement [Abstract] Hedging Relationship [Axis] Hedging Relationship [Axis] Additional Paid-in Capital [Member] Additional Paid-in Capital [Member] Canadian licenses [Member] Licensing Agreements [Member] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Document Fiscal Period Focus Document Fiscal Period Focus Proceeds from Sale of Equity Method Investments Proceeds from Sale of Equity Method Investments Weighted Average Number of Shares Outstanding, Diluted Weighted Average Number of Shares Outstanding, Diluted Loss Contingencies [Line Items] Loss Contingencies [Line Items] Notes Payable Notes Payable, Current Accounts Receivable [Member] Accounts Receivable [Member] Senior notes due 2022 [Member] Senior notes due 2022 [Member] Senior notes due 2022 [Member] Short term debt issuance costs Short term debt issuance costs Short term debt issuance costs Retained earnings Common Stock, Value, Issued Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] 3.25% senior notes due 2024 3.25% senior notes due 2024 3.25% senior notes due 2024 Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment and Tax Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment and Tax Swap, Type [Domain] Swap, Type [Domain] Swap, Type [Domain] Short-term Debt [Line Items] Short-Term Debt [Line Items] Potential common shares not included in computation of diluted earnings per share Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Operating Segments Operating Segments [Member] Contingent consideration adjustment Contingent consideration adjustment Contingent consideration adjustment Preferred Stock, Shares Authorized Preferred Stock, Shares Authorized Three month LIBOR Three month LIBOR Three month LIBOR Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents Net Income (Loss) Attributable to Noncontrolling Interest Less: Net earnings attributable to the noncontrolling interest Net Income (Loss) Attributable to Noncontrolling Interest Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Liabilities, Current [Abstract] Liabilities, Current [Abstract] Common shares issued, beginning balance (in shares) Common shares issued, ending balance (in shares) Common Stock, Shares, Issued Common Stock, Shares, Issued Capital Expenditures Incurred but Not yet Paid Capital Expenditures Incurred but Not yet Paid Pension settlement charge Foreign Currency Translation Adjustments [Member] Foreign Currency Translation Adjustments Capitalized Contract Cost [Table Text Block] Capitalized Contract Cost [Table Text Block] Income Statement Location [Domain] Income Statement Location [Domain] Accumulated Other Comprehensive Earnings [Roll Forward] Accumulated Other Comprehensive Earnings [Roll Forward] Accumulated Other Comprehensive Earnings [Roll Forward] Finance Lease, Liability, Current Finance Lease, Liability, Current Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Amendment Flag Amendment Flag Net Cash Provided by (Used in) Investing Activities Net cash used for investing activities Net Cash Provided by (Used in) Investing Activities Other comprehensive earnings (loss), net of tax Other comprehensive earnings, net of tax Other Comprehensive Income (Loss), Net of Tax Proceeds from revolving credit facilities Proceeds from Long-Term Lines of Credit Comprehensive earnings attributable to Laboratory Corporation of America Holdings Comprehensive Income (Loss), Net of Tax, Attributable to Parent Company's population of financial assets and liabilities subject to fair value measurements Fair Value, Liabilities Measured on Recurring Basis [Table Text Block] Goodwill, Acquired During Period Goodwill, Acquired During Period Business Acquisition, Pro Forma Revenue Business Acquisition, Pro Forma Revenue Tax effect of adjustments Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax Entity Current Reporting Status Entity Current Reporting Status Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets Disclosure [Abstract] Other assets, net Other Assets, Noncurrent Depreciation and amortization Depreciation, Depletion and Amortization Adjustments to goodwill Goodwill, Translation and Purchase Accounting Adjustments Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Contract with Customer, Duration [Axis] Contract with Customer, Duration [Axis] Estimated amortization expense, Thereafter Finite-Lived Intangible Asset, Expected Amortization, after Year Five Unbilled Services, Allowance for Credit Loss Unbilled Services, Allowance for Credit Loss Unbilled Services, Allowance for Credit Loss Dividends Payable, Amount Per Share Dividends Payable, Amount Per Share Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Continuing Operations Property, plant and equipment, net Property, Plant and Equipment, Net Supplemental Cash Flow Information Cash Flow, Supplemental Disclosures [Text Block] Dividends Dividends Dividends Other, net Other Nonoperating Income (Expense) Deferred income taxes and other tax liabilities Deferred income taxes and other tax liabilities Represents the noncurrent portion of deferred tax liabilities, which result from applying the applicable tax rate to net taxable temporary differences pertaining to each jurisdiction to which the entity is obligated to pay income tax, combined with the noncurrent portion of the amount recognized for uncertain tax positions as of the balance sheet date. A noncurrent taxable temporary difference is a difference between the tax basis and the carrying amount of a noncurrent asset or liability in the financial statements prepared in accordance with generally accepted accounting principles. In a classified statement of financial position, an enterprise shall separate deferred tax liabilities and assets into a current amount and a noncurrent amount. Deferred tax liabilities and assets shall be classified as current or noncurrent based on the classification of the related asset or liability for financial reporting. A deferred tax liability or asset that is not related to an asset or liability for financial reporting, including deferred tax assets related to carryforwards, shall be classified according to the expected reversal date of the temporary difference. Balance Sheet Location [Axis] Balance Sheet Location [Axis] Basis of Presentation and Significant Accounting Policies [Text Block] Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block] Common Stock, Shares Authorized Common Stock, Shares Authorized Noncontrolling interest puts Fair Value Liabilities Measured On Recurring Basis Noncontrolling Interest Puts This element represents a certain statement of financial position liability caption which represents a class of liabilities, or which may include an individual liability, measured at fair value on a recurring basis. Total liabilities and shareholders' equity Accumulated Other Comprehensive Earnings, Beginning balance Accumulated Other Comprehensive Earnings, Ending balance Accumulated Other Comprehensive Income (Loss), Net of Tax Ownership percentage below which investments are generally accounted for on the cost method (in thousandths) Cost Method Investments Maximum Ownership Percentage This element represents the maximum ownership percentage of cost-method investments held by the Company. Generally, such investments do not have readily determinable fair values and are not required to be accounted for by the equity method. The carrying amount of such securities equates to cost, adjusted for other-than-temporary impairment. Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Total current assets Assets, Current Allowance for Credit Loss, Write Off Allowance for Credit Loss, Write Off Allowance for Credit Loss, Write Off Income taxes, net of refunds Income Taxes Paid, Net Business Acquisition [Line Items] Business Acquisition [Line Items] Entity Small Business Entity Small Business Preferred Stock and Common Shareholders' Equity Stockholders' Equity Note Disclosure [Text Block] Contract with Customer, Duration [Domain] Contract with Customer, Duration [Domain] Line of Credit Facility [Table] Line of Credit Facility [Table] Long Term Contracts Duration Minimum Long Term Contracts Duration Minimum Long Term Contracts Duration Minimum Income [Abstract] Income [Abstract] Supplemental Cash Flow Information Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Shares [Abstract] Shares [Abstract] Credit Facility, Maximum Letters of Credit Credit Facility, Maximum Letters of Credit Credit Facility, Maximum Letters of Credit Increase in accounts receivable (net) Increase (Decrease) in Accounts Receivable Title of 12(b) Security Title of 12(b) Security Senior notes due 2024 Senior notes due 2024 [Member] Senior notes due 2024 Subordinated Borrowing, Interest Rate Subordinated Borrowing, Interest Rate Repayments of Lines of Credit Repayments of Lines of Credit Debt Instrument [Line Items] Debt Instrument [Line Items] Class of Stock [Line Items] Class of Stock [Line Items] Segment Reporting Disclosure [Text Block] Segment Reporting Disclosure [Text Block] Amount of Deferred Costs Related to Long-term Contracts Amount of Deferred Costs Related to Long-Term Contracts Schedule of Intangible Assets and Goodwill [Table Text Block] Schedule of Intangible Assets and Goodwill [Table Text Block] Estimated amortization expense, 2013 Finite-Lived Intangible Asset, Expected Amortization, Year Two Noncontrolling Interest [Table] Noncontrolling Interest [Table] LIABILITIES AND SHAREHOLDERS' EQUITY Liabilities and Equity [Abstract] Fair Value, Liabilities Measured on Recurring Basis [Table] Fair Value, Recurring and Nonrecurring [Table] Supplies inventories Inventory, Net Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Consideration Transferred Accounts Payable, Current Accounts Payable, Current Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Liabilities Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Liabilities Hedging Relationship [Domain] Hedging Relationship [Domain] Entity Filer Category Entity Filer Category Net earnings, basic (in shares) Weighted Average Number of Shares Outstanding, Basic UNITED STATES UNITED STATES Security Exchange Name Security Exchange Name Acquired Finite-lived Intangible Assets, Weighted Average Useful Life Acquired Finite-Lived Intangible Assets, Weighted Average Useful Life Derivative, Notional Amount Derivative, Notional Amount Letters of Credit Outstanding, Amount Letters of Credit Outstanding, Amount Line of Credit Facility, Commitment Fee Description Line of Credit Facility, Commitment Fee Description Short-term Debt, Type [Domain] Short-Term Debt, Type [Domain] Dividends Payable, Date to be Paid Dividends Payable, Date to be Paid Deferred Income Taxes and Other Assets, Current Deferred Income Taxes and Other Assets, Current Drug Development Drug Development [Member] Covance Drug Development [Member] Dividends Payable, Date Declared Dividends Payable, Date Declared Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Cover [Abstract] Cover [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Level 3 [Member] Fair Value, Inputs, Level 3 [Member] Accounts Receivable, Allowance for Credit Loss Accounts Receivable, Allowance for Credit Loss Business Combinations [Abstract] Business Combinations [Abstract] Segment Reporting [Abstract] Segment Reporting [Abstract] 2022 Swap Agreements 2022 Swap Agreements [Member] 2022 Swap Agreements Corporate Segment [Member] Corporate Segment [Member] Payment, Tax Withholding, Share-based Payment Arrangement Payment, Tax Withholding, Share-Based Payment Arrangement Liabilities and Equity Liabilities and Equity Senior notes due 2031 Senior notes due 2031 [Member] Senior notes due 2031 Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Goodwill [Roll Forward] Goodwill [Roll Forward] Timing of Transfer of Good or Service [Domain] Timing of Transfer of Good or Service [Domain] Dilutive effect of employee stock options and awards, (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements Payments to Acquire Businesses, Net of Cash Acquired Payments to Acquire Businesses, Net of Cash Acquired Payments to Acquire Businesses, Net of Cash Acquired Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 2 [Member] Current Fiscal Year End Date Current Fiscal Year End Date Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Assets Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Assets Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Net Income (Loss) Available to Common Stockholders, Diluted Net Income (Loss) Available to Common Stockholders, Diluted Diluted earnings per common share (in dollars per share) Earnings Per Share, Diluted Intangible Assets, Net (Excluding Goodwill) Intangible Assets, Net (Excluding Goodwill) Intangible Assets, Net (Excluding Goodwill) Proceeds from sale of assets Proceeds from Sale of Property, Plant, and Equipment Stock compensation APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Consolidation Items [Axis] Consolidation Items [Axis] Long-term debt, less current portion Liabilities, Current Notes Payable, Noncurrent Notes Payable, Noncurrent Revenue, Remaining Performance Obligation, Amount Revenue, Remaining Performance Obligation, Amount Other income (expenses): Nonoperating Income (Expense) [Abstract] Other Comprehensive Income (Loss), before Reclassifications, before Tax Other Comprehensive Income (Loss), before Reclassifications, before Tax Rollforward of Share Repurchase Program Outstanding Stock Repurchase Authorization [Abstract] 2018 Swap Agreements 2018 Swap Agreements [Member] 2018 Swap Agreements Entity Address, Address Line One Entity Address, Address Line One Contract with Customer, Asset, before Allowance for Credit Loss Contract with Customer, Asset, before Allowance for Credit Loss Tax effect of adjustments Other Comprehensive Income (Loss), Tax Cost of Revenue Cost of Revenue Contract with Customer, Liability Contract with Customer, Liability Product and Service [Axis] Product and Service [Axis] Europe [Member] Europe [Member] Class of Stock [Domain] Class of Stock [Domain] Unbilled Contracts Receivable Unbilled Contracts Receivable Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Net Restructuring Charges Net Restructuring Charges Amount charged against earnings in the period for incurred and estimated costs, excluding asset retirement obligations, associated with exit from or disposal of business activities or restructurings pursuant to a program that is planned and controlled by management, and changes either scope of business by an entity, or manner business is conducted. May include amount of reversals and other adjustments during the period to amounts of previously accrued liabilities for specified types of restructuring costs. Schedule Of Other Intangible Assets By Major Class [Domain] Schedule Of Other Intangible Assets By Major Class [Domain] Interest Expense Interest expense Interest Expense Trade Names [Member] Trade Names [Member] Credit Facility [Axis] Credit Facility [Axis] Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents [Abstract] Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents [Abstract] Equity [Abstract] Equity [Abstract] Debt Conversion [Line Items] Debt Conversion [Line Items] Entity Tax Identification Number Entity Tax Identification Number Foreign Currency Contract, Asset, Fair Value Disclosure Foreign Currency Contract, Asset, Fair Value Disclosure Impaired Long-Lived Assets Held and Used by Type [Axis] Impaired Long-Lived Assets Held and Used by Type [Axis] Schedule of Short-term Debt [Table] Schedule of Short-Term Debt [Table] Disaggregation of Revenue [Table Text Block] Disaggregation of Revenue [Table Text Block] Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Contract with Customer, Asset, after Allowance for Credit Loss, Current Contract with Customer, Asset, after Allowance for Credit Loss, Current Noncompete Agreements [Member] Noncompete Agreements [Member] 3.60% senior notes due 2027 3.60% senior notes due 2027 3.60% senior notes due 2027 3.60% senior notes due 2025 3.60% senior notes due 2025 3.60% senior notes due 2025 Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Accrued Liabilities [Member] Accrued Liabilities [Member] 2.70% senior notes due 2031 2.70% senior notes due 2031 2.70% senior notes due 2031 Estimated amortization expense, 2016 Finite-Lived Intangible Asset, Expected Amortization, Year Five Entity Central Index Key Entity Central Index Key Cash Flow Location [Axis] Cash Flow Location [Axis] Cash Flow Location [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] 4.70% senior notes due 2045 4.70% senior notes due 2045 4.70% senior notes due 2045 Entity [Domain] Entity [Domain] City Area Code City Area Code ASSETS Assets [Abstract] Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Payments of Ordinary Dividends Payments of Ordinary Dividends CASH FLOWS FROM FINANCING ACTIVITIES: Net Cash Provided by (Used in) Financing Activities [Abstract] Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased Biopharmaceutical and medical device companies [Member] Biopharmaceutical and medical device companies [Member] Biopharmaceutical and medical device companies [Member] Foreign currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax Schedule Of Other Intangible Assets By Major Class [Axis] Schedule Of Other Intangible Assets By Major Class [Axis] Percent of Revenue Contributed Percent of Revenue Contributed Percent of Revenue Contributed Disclosure of non-cash financing and investing activities: Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Stock compensation Share-Based Payment Arrangement, Noncash Expense Payments to Acquire Equity Method Investments Payments to Acquire Equity Method Investments Variable Rate [Axis] Variable Rate [Axis] Commitments and contingent liabilities Other Liabilities, Noncurrent Equity method income, net Income (Loss) from Equity Method Investments North America North America [Member] In Process R&A and Media In Process R&A and Media [Member] In Process R&A and Media Cash payments for laboratory-related assets Payments to Acquire Property, Plant, and Equipment Asset Impairment Charges Asset Impairment Charges Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Estimated amortization expense, 2012 Finite-Lived Intangible Asset, Expected Amortization, Year One Reconciliation of Basic earnings per Share to Diluted Earnings per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Tax effect of adjustments Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax Line of Credit Facility, Interest Rate at Period End Line of Credit Facility, Interest Rate at Period End Contract with Customer, Sales Channel [Domain] Contract with Customer, Sales Channel [Domain] Customer [Domain] Customer [Domain] Percent of remaining performance obligations recognized as revenue in next year Percent of remaining performance obligations recognized as revenue in next year Percent of remaining performance obligations recognized as revenue in next year