CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement [Abstract]
Net revenues	$ 1,925	$ 1,902	$ 3,764	$ 3,648
Operating costs and expenses:
Cost of services	1,182	1,174	2,345	2,275
Selling, general and administrative	429	440	848	855
Amortization expense	20	25	41	47
Other operating (income) expense, net	(7)	1	1	1
Total operating costs and expenses	1,624	1,640	3,235	3,178
Operating income	301	262	529	470
Other income (expense):
Interest expense, net	(37)	(42)	(82)	(81)
Equity in earnings of equity method investees	7	6	14	12
Other (expense) income, net	(64)	3	(142)	4
Total non-operating expenses, net	(94)	(33)	(210)	(65)
Income before income taxes	207	229	319	405
Income tax expense	78	87	120	152
Net income	129	142	199	253
Less: Net income attributable to noncontrolling interests	11	9	20	16
Net income attributable to Quest Diagnostics	$ 118	$ 133	$ 179	$ 237
Earnings per share attributable to Quest Diagnostics’ common stockholders:
Basic (per share)	$ 0.82	$ 0.92	$ 1.24	$ 1.64
Diluted (per share)	$ 0.81	$ 0.92	$ 1.23	$ 1.63
Weighted average common shares outstanding:
Basic (in Shares)	144	144	144	144
Diluted (in Shares)	145	145	145	145
Dividends per common share	$ 0.38	$ 0.33	$ 0.76	$ 0.66