Condensed Consolidated Statements of Changes in Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Net Unrealized (Losses) Gains on Investments [Member]	Foreign Currency Translation [Member]	Nonredeemable Noncontrolling Interests [Member]
Balance at Dec. 31, 2018	$ 54,319	$ 10	$ 0	$ 55,846	$ (264)	$ (3,896)	$ 2,623
Balance (Adjustment to adopt ASU 2016-02) at Dec. 31, 2018	(18)			(13)			(5)
Balance (in shares) at Dec. 31, 2018		960
Net earnings attributable to UnitedHealth Group common shareholders	3,467			3,467
Net earnings attributable to nonredeemable noncontrolling interest							60
Net Earnings, Including Portion Attributable to Nonredeemable Noncontrolling Interest	3,527
Other comprehensive income (loss)	402				404	(2)
Issuances of common stock, and related tax effects (in shares)		5
Issuances of common stock, and related tax effects	56	$ 0	56
Share-based compensation	239		239
Common share repurchases (in shares)		(12)
Common share repurchases	(3,002)	$ 0	(34)	(2,968)
Cash dividends paid on common shares	(860)			(860)
Redeemable noncontrolling interests fair value and other adjustments	(152)		(152)
Acquisition and other adjustments of nonredeemable noncontrolling interests	23		(109)				132
Distribution to nonredeemable noncontrolling interests	(83)						(83)
Balance at Mar. 31, 2019	54,451	$ 10	0	55,472	140	(3,898)	2,727
Balance (in shares) at Mar. 31, 2019		953
Balance at Dec. 31, 2019	60,436	$ 9	7	61,178	589	(4,167)	2,820
Balance (Adjustment to Adopt ASU 2016-13) at Dec. 31, 2019	$ (28)			(28)
Balance (in shares) at Dec. 31, 2019	948	948
Net earnings attributable to UnitedHealth Group common shareholders	$ 3,382			3,382
Net earnings attributable to nonredeemable noncontrolling interest							59
Net Earnings, Including Portion Attributable to Nonredeemable Noncontrolling Interest	3,441
Other comprehensive income (loss)	(1,782)				(283)	(1,499)
Issuances of common stock, and related tax effects (in shares)		5
Issuances of common stock, and related tax effects	321	$ 1	320
Share-based compensation	234		234
Common share repurchases (in shares)		(6)
Common share repurchases	(1,691)	$ 0	(510)	(1,181)
Cash dividends paid on common shares	(1,024)			(1,024)
Redeemable noncontrolling interests fair value and other adjustments	(51)		(51)
Acquisition and other adjustments of nonredeemable noncontrolling interests	50						50
Distribution to nonredeemable noncontrolling interests	(43)						(43)
Balance at Mar. 31, 2020	$ 59,863	$ 10	$ 0	$ 62,327	$ 306	$ (5,666)	$ 2,886
Balance (in shares) at Mar. 31, 2020	947	947