CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 237	$ 276	$ 703	$ 899
Other comprehensive income (loss):
Foreign currency translation adjustment	(4)	(8)	1	(17)
Other comprehensive (loss) income	(4)	(8)	1	(17)
Comprehensive income	233	268	704	882
Less: Comprehensive income attributable to noncontrolling interests	12	20	41	54
Comprehensive income attributable to Quest Diagnostics	$ 221	$ 248	$ 663	$ 828