CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Unaudited) (USD $) In Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income [Member]
BALANCE at Dec. 31, 2012	$ 2,717.4	$ 11.3	$ 0	$ 3,588.5	$ (951.8)	$ 69.4
Net earnings attributable to Laboratory Corporation of America Holdings	299.2			299.2
Other comprehensive earnings, net of tax	(32.7)					(32.7)
Issuance of common stock under employee stock plans	131.1	0.2	130.9
Surrender of restricted stock and performance share awards	(7.1)				(7.1)
Conversion of zero-coupon convertible debt	4.7	0	4.7
Stock compensation	22.1		22.1
Income tax benefit from stock options exercised	7.9		7.9
Purchase of common stock	(479.2)	(0.5)	(165.6)	(313.1)
BALANCE at Jun. 30, 2013	2,663.4	11.0	0	3,574.6	(958.9)	36.7
BALANCE at Dec. 31, 2013	2,491.3	10.5	0	3,373.5	(958.9)	66.2
Net earnings attributable to Laboratory Corporation of America Holdings	254.4			254.4
Other comprehensive earnings, net of tax	(7.7)					(7.7)
Issuance of common stock under employee stock plans	58.9	0	58.9
Surrender of restricted stock and performance share awards	(6.6)				(6.6)
Conversion of zero-coupon convertible debt	4.5
Stock compensation	23.6		23.6
Income tax benefit from stock options exercised	2.2		2.2
Purchase of common stock	(164.2)	(0.1)	(89.2)	(74.9)
BALANCE at Jun. 30, 2014	$ 2,656.4	$ 10.4	$ 0	$ 3,553.0	$ (965.5)	$ 58.5