CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Statement [Abstract]
Net revenues	$ 1,906	$ 1,925	$ 3,769	$ 3,764
Operating costs, expenses and other income:
Cost of services	1,155	1,182	2,299	2,345
Selling, general and administrative	430	429	872	848
Amortization expense	17	20	36	41
Gain on disposition of business	(118)	0	(118)	0
Other operating (income) expense, net	0	(7)	1	1
Total operating costs, expenses and other income, net	1,484	1,624	3,090	3,235
Operating income	422	301	679	529
Other income (expense):
Interest expense, net	(34)	(37)	(70)	(82)
Other expense, net	(5)	(64)	(54)	(142)
Total non-operating expenses, net	(39)	(101)	(124)	(224)
Income before income taxes and equity in earnings of equity method investees	383	200	555	305
Income tax expense	(183)	(78)	(250)	(120)
Equity in earnings of equity method investees, net of taxes	9	7	19	14
Net income	209	129	324	199
Less: Net income attributable to noncontrolling interests	14	11	26	20
Net income attributable to Quest Diagnostics	$ 195	$ 118	$ 298	$ 179
Earnings per share attributable to Quest Diagnostics’ common stockholders:
Basic (per share)	$ 1.38	$ 0.82	$ 2.10	$ 1.24
Diluted (per share)	$ 1.37	$ 0.81	$ 2.08	$ 1.23
Weighted average common shares outstanding:
Basic (in Shares)	140	144	141	144
Diluted (in Shares)	142	145	143	145
Dividends per common share	$ 0.40	$ 0.38	$ 0.80	$ 0.76