CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Net revenues	$ 7,709	$ 7,515	$ 7,493
Operating costs and expenses and other operating income:
Cost of services	4,719	4,616	4,657
Selling, general and administrative	1,750	1,681	1,679
Amortization of intangible assets	74	72	81
Gain on disposition of business	0	(118)	(334)
Other operating expense (income), net	1	(13)	11
Total operating costs and expenses, net	6,544	6,238	6,094
Operating income	1,165	1,277	1,399
Other income (expense):
Interest expense, net	(151)	(143)	(153)
Other income (expense), net	16	(48)	(143)
Total non-operating expenses, net	(135)	(191)	(296)
Income before income taxes and equity in earnings of equity method investees	1,030	1,086	1,103
Income tax expense	(241)	(429)	(373)
Equity in earnings of equity method investees, net of taxes	35	39	23
Net income	824	696	753
Less: Net income attributable to noncontrolling interests	52	51	44
Net income attributable to Quest Diagnostics	$ 772	$ 645	$ 709
Earnings per share attributable to Quest Diagnostics’ common stockholders:
Basic (in dollars per share)	$ 5.63	$ 4.58	$ 4.92
Diluted (in dollars per share)	5.50	4.51	4.87
Dividends per common share	$ 1.80	$ 1.65	$ 1.52