CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 205	$ 354	$ 529	$ 553
Other comprehensive (loss) income:
Currency translation	(5)	(5)	(23)	(7)
Market valuation, net of taxes	0	(2)	(1)	0
Net deferred loss on cash flow hedges, net of taxes	0	1	1	3
Other comprehensive loss	(5)	(6)	(23)	(4)
Comprehensive income	200	348	506	549
Less: Comprehensive income attributable to noncontrolling interests	13	12	39	32
Comprehensive income attributable to Quest Diagnostics	$ 187	$ 336	$ 467	$ 517