CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Net revenues	$ 1,885	$ 1,880	$ 5,654	$ 5,644
Operating costs, expenses and other income:
Cost of services	1,157	1,162	3,456	3,507
Selling, general and administrative	409	402	1,281	1,250
Amortization expense	18	20	54	61
Gain on disposition of business	0	(334)	(118)	(334)
Other operating income, net	(21)	(1)	(20)	0
Total operating costs, expenses and other income, net	1,563	1,249	4,653	4,484
Operating income	322	631	1,001	1,160
Other income (expense):
Interest expense, net	(37)	(35)	(107)	(117)
Other income (expense), net	4	(4)	(50)	(146)
Total non-operating expenses, net	(33)	(39)	(157)	(263)
Income before income taxes and equity in earnings of equity method investees	289	592	844	897
Income tax expense	(95)	(239)	(345)	(359)
Equity in earnings of equity method investees, net of taxes	11	1	30	15
Net income	205	354	529	553
Less: Net income attributable to noncontrolling interests	13	12	39	32
Net income attributable to Quest Diagnostics	$ 192	$ 342	$ 490	$ 521
Earnings per share attributable to Quest Diagnostics’ common stockholders:
Basic (per share)	$ 1.37	$ 2.37	$ 3.46	$ 3.61
Diluted (per share)	$ 1.34	$ 2.35	$ 3.42	$ 3.58
Weighted average common shares outstanding:
Basic (in Shares)	139	144	141	144
Diluted (in Shares)	142	145	143	145
Dividends per common share	$ 0.40	$ 0.38	$ 1.2	$ 1.14