CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Statement [Abstract]
Net revenues	$ 9,872	$ 9,252	$ 9,883
Operating costs and expenses and other operating income:
Cost of services	6,628	6,199	6,450
Selling, general and administrative	1,770	1,642	1,874
Amortization of intangible assets	127	108	120
Other operating expense, net	1	41	11
Total operating costs and expenses, net	8,526	7,990	8,455
Operating income	1,346	1,262	1,428
Other income (expense):
Interest expense, net	(201)	(152)	(138)
Other income (expense), net	30	20	(55)
Total non-operating expense, net	(171)	(132)	(193)
Income before income taxes and equity in earnings of equity method investees	1,175	1,130	1,235
Income tax expense	(273)	(248)	(264)
Equity in earnings of equity method investees, net of taxes	19	26	44
Net income	921	908	1,015
Less: Net income attributable to noncontrolling interests	50	54	69
Net income attributable to Quest Diagnostics	$ 871	$ 854	$ 946
Earnings per share attributable to Quest Diagnostics’ common stockholders:
Basic (in dollars per share)	$ 7.78	$ 7.59	$ 8.10
Diluted (in dollars per share)	$ 7.69	$ 7.49	$ 7.97