CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Income Statement [Abstract]
Net sales	$ 1,419.4	$ 1,404.5	$ 4,266.1	$ 4,176.2
Cost of sales	863.3	836.0	2,554.4	2,451.1
Gross profit	556.1	568.5	1,711.7	1,725.1
Selling, general and administrative expenses	285.1	283.8	835.8	889.3
Amortization of intangibles and other assets	21.1	21.2	63.1	64.6
Restructuring and other special charges	4.8	24.1	4.6	70.3
Operating income	245.1	239.4	808.2	700.9
Other income (expenses):
Interest expense	(24.1)	(20.3)	(66.9)	(65.3)
Equity method income, net	5.1	2.5	17.4	6.6
Investment income	0.3	0.2	0.7	0.7
Other, net	0.5	(1.7)	(6.7)	(1.8)
Earnings before income taxes	226.9	220.1	752.7	641.1
Provision for income taxes	78.5	82.5	288.5	246.2
Net earnings	148.4	137.6	464.2	394.9
Less: Net earnings attributable to the noncontrolling interest	(0.4)	(3.3)	(1.3)	(10.6)
Net earnings attributable to Laboratory Corporation of America Holdings	$ 148.0	$ 134.3	$ 462.9	$ 384.3
Basic earnings per common share (in dollars per share)	$ 1.56	$ 1.34	$ 4.81	$ 3.82
Diluted earnings per common share (in dollars per share)	$ 1.53	$ 1.31	$ 4.72	$ 3.76