CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Net revenues	$ 1,863	$ 1,839
Operating costs, expenses and other income:
Cost of services	1,144	1,163
Selling, general and administrative	442	419
Amortization expense	19	21
Other operating expense, net	1	8
Total operating costs, expenses and other income, net	1,606	1,611
Operating income	257	228
Other income (expense):
Interest expense, net	(36)	(45)
Other expense, net	(49)	(78)
Total non-operating expenses, net	(85)	(123)
Income before income taxes and equity in earnings of equity method investees	172	105
Income tax expense	(68)	(42)
Equity in earnings of equity method investees, net of taxes	10	7
Net income	114	70
Less: Net income attributable to noncontrolling interests	12	9
Net income attributable to Quest Diagnostics	$ 102	$ 61
Earnings per share attributable to Quest Diagnostics’ common stockholders:
Basic (per share)	$ 0.71	$ 0.42
Diluted (per share)	$ 0.70	$ 0.42
Weighted average common shares outstanding:
Basic (in Shares)	143	144
Diluted (in Shares)	144	146
Dividends per common share	$ 0.40	$ 0.38