CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 2,080	$ 1,499	$ 906
Other comprehensive income (loss):
Foreign currency translation adjustment	13	15	7
Net change in available-for-sale debt securities, net of taxes	(7)	0	8
Net deferred gain on cash flow hedges, net of taxes	1	3	5
Other comprehensive income	7	18	20
Comprehensive income	2,087	1,517	926
Less: Comprehensive income attributable to noncontrolling interests	85	68	48
Comprehensive income attributable to Quest Diagnostics	$ 2,002	$ 1,449	$ 878