CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues	$ 2,831.3	$ 2,621.4	$ 8,545.9	$ 7,563.3
Cost of Revenue	2,041.4	1,837.2	6,141.9	5,288.6
Gross Profit	789.9	784.2	2,404.0	2,274.7
Selling, general and administrative expenses	381.8	381.3	1,174.0	1,081.9
Amortization of intangibles and other assets	54.7	54.6	175.5	153.6
Net restructuring and other special charges	10.0	21.6	36.5	64.6
Operating Income (Loss)	343.4	326.7	1,018.0	974.6
Other income (expenses):
Interest expense	(59.4)	(59.9)	(186.0)	(167.3)
Equity method income, net	3.0	3.2	8.5	10.0
Investment income	2.8	0.7	4.2	1.4
Other, net	209.8	(3.9)	209.1	(7.4)
Earnings before income taxes	499.6	266.8	1,053.8	811.3
Provision for income taxes	180.6	92.5	328.1	268.6
Net earnings	319.0	174.3	725.7	542.7
Less: Net earnings attributable to the noncontrolling interest	(0.2)	(2.8)	0.1	(3.4)
Net earnings attributable to Laboratory Corporation of America Holdings	$ 318.8	$ 171.5	$ 725.8	$ 539.3
Basic earnings per common share (in dollars per share)	$ 3.14	$ 1.68	$ 7.13	$ 5.27
Diluted earnings per common share (in dollars per share)	$ 3.10	$ 1.65	$ 7.04	$ 5.19
Previous Accounting Guidance [Member]
Gross profit, as reported		$ 882.8		$ 2,548.2
Net income (loss), including portion attributable to NCI, as reported		183.4		564.8
Net income (loss) attributable to Parent, as reported		180.6		561.4
Revenues		2,655.2		7,645.1
Cost of Revenue		1,772.4		5,096.9
Selling, general and administrative expenses		465.3		1,320.0
Other income (expenses):
Provision for income taxes		97.7		281.1
Less: Net earnings attributable to the noncontrolling interest		$ (2.8)		$ (3.4)
Basic earnings per common share (in dollars per share)		$ 1.77		$ 5.48
Diluted earnings per common share (in dollars per share)		$ 1.74		$ 5.40