CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Net revenues	$ 10,788	$ 9,437	$ 7,726
Operating costs and expenses and other operating expense (income):
Cost of services	6,579	5,804	5,037
Selling, general and administrative	1,727	1,550	1,457
Amortization of intangible assets	103	103	96
Other operating (income) expense, net	(2)	9	(95)
Total operating costs and expenses, net	8,407	7,466	6,495
Operating income	2,381	1,971	1,231
Other income (expense):
Interest expense, net	(151)	(163)	(175)
Other income, net	369	76	20
Total non-operating income (expense), net	218	(87)	(155)
Income from continuing operations before income taxes and equity in earnings of equity method investees	2,599	1,884	1,076
Income tax expense	(597)	(460)	(247)
Equity in earnings of equity method investees, net of taxes	78	75	57
Income from continuing operations	2,080	1,499	886
Income from discontinued operations, net of taxes	0	0	20
Net income	2,080	1,499	906
Less: Net income attributable to noncontrolling interests	85	68	48
Net income attributable to Quest Diagnostics	1,995	1,431	858
Amounts attributable to Quest Diagnostics’ common stockholders:
Income from continuing operations	1,995	1,431	838
Income from discontinued operations, net of taxes	0	0	20
Net income attributable to Quest Diagnostics	$ 1,995	$ 1,431	$ 858
Earnings per share attributable to Quest Diagnostics’ common stockholders - basic:
Income from continuing operations (in dollars per share)	$ 15.85	$ 10.62	$ 6.21
Income from discontinued operations (in dollars per share)	0	0	0.15
Net income (in dollars per share)	15.85	10.62	6.36
Earnings per share attributable to Quest Diagnostics’ common stockholders - diluted:
Income from continuing operations (in dollars per share)	15.55	10.47	6.13
Income from discontinued operations (in dollars per share)	0	0	0.15
Net income (in dollars per share)	$ 15.55	$ 10.47	$ 6.28