CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Net revenues	$ 1,884	$ 1,817
Operating costs and expenses and other operating income:
Cost of services	1,226	1,165
Selling, general and administrative	363	355
Amortization of intangible assets	22	17
Other operating expense, net	1	1
Total operating costs and expenses, net	1,612	1,538
Operating income	272	279
Other income (expense):
Interest expense, net	(41)	(36)
Other (expense) income, net	(2)	3
Total non-operating expenses, net	(43)	(33)
Income before income taxes and equity in earnings of equity method investees	229	246
Income tax expense	(52)	(78)
Equity in earnings of equity method investees, net of taxes	12	7
Net income	189	175
Less: Net income attributable to noncontrolling interests	12	11
Net income attributable to Quest Diagnostics	$ 177	$ 164
Earnings per share attributable to Quest Diagnostics’ common stockholders:
Basic (per share)	$ 1.30	$ 1.19
Diluted (per share)	$ 1.27	$ 1.16
Weighted average common shares outstanding:
Basic (in Shares)	136	137
Diluted (in Shares)	139	141
Dividends per common share	$ 0.50	$ 0.45