CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Net revenues	$ 1,839	$ 1,746
Operating costs and expenses:
Cost of services	1,163	1,101
Selling, general and administrative	419	415
Amortization expense	21	22
Other operating expense, net	8	0
Total operating costs and expenses	1,611	1,538
Operating income	228	208
Other income (expense):
Interest expense, net	(45)	(39)
Equity in earnings of equity method investees	7	6
Other (expense) income, net	(78)	1
Total non-operating expenses, net	(116)	(32)
Income before income taxes	112	176
Income tax expense	42	65
Net income	70	111
Less: Net income attributable to noncontrolling interests	9	7
Net income attributable to Quest Diagnostics	$ 61	$ 104
Earnings per share attributable to Quest Diagnostics’ common stockholders:
Basic (per share)	$ 0.42	$ 0.72
Diluted (per share)	$ 0.42	$ 0.71
Weighted average common shares outstanding:
Basic	144	144
Diluted	146	145
Dividends per common share	$ 0.38	$ 0.33