Bridge Term Credit Facility Agreement, Maximum Borrowing Amount

No definition available.

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- Definition

Credit Facility, Maximum Swing Line Borrowings

+ References

No definition available.

+ Details

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- Definition

Credit Facility Option to Increase

+ References

No definition available.

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- Definition

Debt to EBITDA (Leverage) Ratio

+ References

No definition available.

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- Definition

Make-whole payment

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- Definition

Net Proceeds from Debt

+ References

No definition available.

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- Definition

Amount of long-term debt due after one year or the normal operating cycle, if longer, assumed at the acquisition date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (c)

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- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

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-Topic 835

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-Section 55

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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-Topic 210

-SubTopic 10

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-Subparagraph (SX 210.5-02.22(a)(1))

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- Definition

The percentage points added to the reference rate to compute the variable rate on the interest rate derivative.

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- Definition

Net fair value of all derivative instruments designated as fair value hedging instruments.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

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-Name Regulation S-X (SX)

-Number 210

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-Paragraph 19, 22

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- Definition

Carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion. Senior note holders are paid off in full before any payments are made to junior note holders.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22)

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-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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DEBT (Senior Notes) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Jan. 30, 2015	Dec. 31, 2014	Dec. 19, 2014	Nov. 19, 2010	Feb. 19, 2015	Nov. 02, 2014
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				$ 1,000.0
Credit Facility Option to Increase				250.0lh_CreditFacilityOptiontoIncrease
Credit Facility, Maximum Swing Line Borrowings				100.0
Senior Notes, Noncurrent		2,900.0us-gaap_SeniorLongTermNotes
Debt to EBITDA (Leverage) Ratio	4.20lh_DebtToEbitdaLeverageRatio
Fair Value Hedges, Net	34.0us-gaap_FairValueHedgesAtFairValueNet		18.5us-gaap_FairValueHedgesAtFairValueNet
Debt Instrument, Face Amount	600.0us-gaap_DebtInstrumentFaceAmount
Derivative, Basis Spread on Variable Rate	2.298%
Senior notes due 2045 [Member]
Debt Instrument [Line Items]
Senior Notes, Noncurrent		900.0
Stated interest rate percentage		4.70%
Senior notes due 2022 [Member]
Debt Instrument [Line Items]
Senior Notes, Noncurrent	500.0	500.0	0
Stated interest rate percentage	3.75%	3.20%
Senior notes due 2017 [Member]
Debt Instrument [Line Items]
Stated interest rate percentage	2.20%
Senior notes due 2020 [Member]
Debt Instrument [Line Items]
Senior Notes, Noncurrent	500.0	500.0	0
Stated interest rate percentage	4.625%	2.625%			4.625%
Debt Instrument, Face Amount			618.5
Covance [Member]
Debt Instrument [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt						250.0
Make-whole payment	37.4
Bridge Term Credit Facility Agreement, Maximum Borrowing Amount				3,250.0			4,250.0
Net Proceeds from Debt		$ 2,870.2