CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Net revenues	$ 9,252	$ 9,883	$ 10,788
Operating costs and expenses and other operating income:
Cost of services	6,199	6,450	6,579
Selling, general and administrative	1,642	1,874	1,727
Amortization of intangible assets	108	120	103
Other operating expense (income), net	41	11	(2)
Total operating costs and expenses, net	7,990	8,455	8,407
Operating income	1,262	1,428	2,381
Other income (expense):
Interest expense, net	(152)	(138)	(151)
Other income (expense), net	20	(55)	369
Total non-operating (expense) income, net	(132)	(193)	218
Income before income taxes and equity in earnings of equity method investees	1,130	1,235	2,599
Income tax expense	(248)	(264)	(597)
Equity in earnings of equity method investees, net of taxes	26	44	78
Net income	908	1,015	2,080
Less: Net income attributable to noncontrolling interests	54	69	85
Net income attributable to Quest Diagnostics	$ 854	$ 946	$ 1,995
Earnings per share attributable to Quest Diagnostics’ common stockholders:
Basic (in dollars per share)	$ 7.59	$ 8.10	$ 15.85
Diluted (in dollars per share)	$ 7.49	$ 7.97	$ 15.55