CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income Statement [Abstract]
Net revenues	$ 2,397	$ 2,338	$ 4,763	$ 4,669
Operating costs and expenses and other operating income:
Cost of services	1,593	1,546	3,188	3,106
Selling, general and administrative	416	416	856	855
Amortization of intangible assets	29	28	58	54
Other operating expense, net	4	0	6	1
Total operating costs and expenses, net	2,042	1,990	4,108	4,016
Operating income	355	348	655	653
Other income (expense):
Interest expense, net	(44)	(37)	(87)	(72)
Other income, net	3	6	12	13
Total non-operating expense, net	(41)	(31)	(75)	(59)
Income before income taxes and equity in earnings of equity method investees	314	317	580	594
Income tax expense	(74)	(75)	(140)	(140)
Equity in earnings of equity method investees, net of taxes	0	7	8	12
Net income	240	249	448	466
Less: Net income attributable to noncontrolling interests	11	14	25	29
Net income attributable to Quest Diagnostics	$ 229	$ 235	$ 423	$ 437
Earnings per share attributable to Quest Diagnostics’ common stockholders:
Basic (in dollars per share)	$ 2.05	$ 2.08	$ 3.79	$ 3.88
Diluted (in dollars per share)	$ 2.03	$ 2.05	$ 3.75	$ 3.83
Weighted average common shares outstanding:
Basic (in Shares)	111	112	111	112
Diluted (in Shares)	112	114	112	114