CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement [Abstract]
Net revenues	$ 1,880	$ 1,904	$ 5,644	$ 5,552
Operating costs and expenses:
Cost of services	1,162	1,178	3,507	3,453
Selling, general and administrative	402	446	1,250	1,301
Amortization expense	20	24	61	71
Gain on contribution of business to joint venture	(334)	0	(334)	0
Other operating (income) expense, net	(1)	0	0	1
Total operating costs and expenses	1,249	1,648	4,484	4,826
Operating income	631	256	1,160	726
Other income (expense):
Interest expense, net	(35)	(41)	(117)	(122)
Other (expense) income, net	(4)	(1)	(146)	3
Total non-operating expenses, net	(39)	(42)	(263)	(119)
Income before income taxes and equity in earnings of equity method investees	592	214	897	607
Income tax expense	(239)	(82)	(359)	(234)
Equity in earnings of equity method investees, net of taxes	1	7	15	19
Net income	354	139	553	392
Less: Net income attributable to noncontrolling interests	12	10	32	26
Net income attributable to Quest Diagnostics	$ 342	$ 129	$ 521	$ 366
Earnings per share attributable to Quest Diagnostics’ common stockholders:
Basic (per share)	$ 2.37	$ 0.89	$ 3.61	$ 2.52
Diluted (per share)	$ 2.35	$ 0.88	$ 3.58	$ 2.51
Weighted average common shares outstanding:
Basic (in Shares)	144	145	144	144
Diluted (in Shares)	145	145	145	145
Dividends per common share	$ 0.38	$ 0.33	$ 1.14	$ 0.99