CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 240	$ 249	$ 448	$ 466
Other comprehensive income (loss):
Foreign currency translation adjustment	(3)	2	(5)	5
Other comprehensive (loss) income	(3)	2	(5)	5
Comprehensive income	237	251	443	471
Less: Comprehensive income attributable to noncontrolling interests	11	14	25	29
Comprehensive income attributable to Quest Diagnostics	$ 226	$ 237	$ 418	$ 442