CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Net sales	$ 1,772.3	$ 1,430.7
Reimbursement Revenue	20.9	0
Revenues	1,793.2	1,430.7
Cost of sales	1,176.3	913.9
Cost of Reimbursable Expense	20.9	0
Cost of Revenue	1,197.2	913.9
Gross profit	596.0	516.8
Selling, general and administrative expenses	415.1	284.9
Amortization of intangibles and other assets	31.4	21.0
Restructuring and other special charges	19.3	7.6
Operating income	130.2	203.3
Other income (expenses):
Interest expense	(104.3)	(25.7)
Equity method income, net	2.7	3.0
Investment income	0.6	0.2
Other, net	1.1	6.9
Earnings before income taxes	30.3	187.7
Provision for income taxes	29.3	74.2
Net earnings	1.0	113.5
Less: Net earnings attributable to the noncontrolling interest	(0.3)	(0.4)
Net earnings attributable to Laboratory Corporation of America Holdings	$ 0.7	$ 113.1
Basic earnings per common share (in dollars per share)	$ 0.01	$ 1.33
Diluted earnings per common share (in dollars per share)	$ 0.01	$ 1.31