CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 209	$ 129	$ 324	$ 199
Other comprehensive (loss) income:
Currency translation	(15)	4	(18)	(2)
Market valuation, net of taxes	(1)	0	(1)	2
Net deferred loss on cash flow hedges, net of taxes	0	1	1	2
Other comprehensive (loss) income	(16)	5	(18)	2
Comprehensive income	193	134	306	201
Less: Comprehensive income attributable to noncontrolling interests	14	11	26	20
Comprehensive income attributable to Quest Diagnostics	$ 179	$ 123	$ 280	$ 181