BUSINESS ACQUISITIONS (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015	Jul. 27, 2016	Feb. 19, 2015	Jan. 30, 2015	Dec. 31, 2014
Business Combination Purchase Price Allocation [Line Items]
Revenues	$ 2,430.7	$ 2,269.1	$ 4,798.7	$ 4,062.3
Operating Income (Loss)	366.9	323.3	668.8	455.7
Other Long-term Debt	715.0		715.0		$ 55.5
Other Significant Noncash Transaction, Value of Consideration Given			40.7	58.8
Net Income (Loss) Attributable to Parent	198.2	$ 169.8	358.4	172.9
Goodwill, Acquired During Period			87.2		3,194.6
Senior Notes, Noncurrent								$ 2,900.0
Goodwill	$ 6,218.3		6,218.3		$ 6,191.9				$ 3,099.4
Cash payments for laboratory-related assets			138.4	102.9
Payments to Acquire Businesses, Net of Cash Acquired			$ 144.1	$ 3,684.4
Covance [Member]
Business Combination Purchase Price Allocation [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt							$ 250.0
Total acquisition consideration (cash and non-cash)							$ 6,150.7
Covance [Member] | Amortization expense [Member]
Business Combination Purchase Price Allocation [Line Items]
Business Combination, Provisional Information, Initial Accounting Incomplete, Items		2.1		3.3
Covance [Member] | Interest Expense [Member]
Business Combination Purchase Price Allocation [Line Items]
Business Combination, Provisional Information, Initial Accounting Incomplete, Items		.6		.1
Covance [Member] | Other Comprehensive Income (Loss) [Member]
Business Combination Purchase Price Allocation [Line Items]
Business Combination, Provisional Information, Initial Accounting Incomplete, Items		-115.6		6.6	102.7
Subsequent Event [Member]
Business Combination Purchase Price Allocation [Line Items]
Total acquisition consideration (cash and non-cash)						$ 302.0
Business Acquisition, Share Price						$ 2.40