CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Statement [Abstract]
Net revenues	$ 2,488	$ 2,295	$ 7,251	$ 6,964
Operating costs and expenses and other operating income:
Cost of services	1,677	1,541	4,865	4,647
Selling, general and administrative	448	380	1,304	1,235
Amortization of intangible assets	32	27	90	81
Other operating expense, net	1	5	7	6
Total operating costs and expenses, net	2,158	1,953	6,266	5,969
Operating income	330	342	985	995
Other income (expense):
Interest expense, net	(49)	(40)	(136)	(112)
Other income (expense), net	15	(3)	27	10
Total non-operating expense, net	(34)	(43)	(109)	(102)
Income before income taxes and equity in earnings of equity method investees	296	299	876	893
Income tax expense	(65)	(68)	(205)	(208)
Equity in earnings of equity method investees, net of taxes	6	6	14	18
Net income	237	237	685	703
Less: Net income attributable to noncontrolling interests	11	12	36	41
Net income attributable to Quest Diagnostics	$ 226	$ 225	$ 649	$ 662
Earnings per share attributable to Quest Diagnostics’ common stockholders:
Basic (in dollars per share)	$ 2.01	$ 1.99	$ 5.80	$ 5.87
Diluted (in dollars per share)	$ 1.99	$ 1.96	$ 5.74	$ 5.79
Weighted average common shares outstanding:
Basic (in Shares)	112	112	111	112
Diluted (in Shares)	113	114	112	114