CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 106	$ 176
Other comprehensive (loss) income:
Foreign currency translation adjustment	(19)	4
Other comprehensive (loss) income	(19)	4
Comprehensive income	87	180
Less: Comprehensive income attributable to noncontrolling interests	7	12
Comprehensive income attributable to Quest Diagnostics	$ 80	$ 168