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 Gains (Losses) on Investments [Member]	Foreign Currency Translation Losses [Member]	Nonredeemable Noncontrolling Interest [Member]
Balance (in shares) at Dec. 31, 2014		954
Balance at Dec. 31, 2014	$ 32,454	$ 10	$ 0	$ 33,836	$ 223	$ (1,615)	$ 0
Net earnings attributable to UnitedHealth Group common shareholders	1,413			1,413
Net Earnings, Including Portion Attributable to Nonredeemable Noncontrolling Interest	1,413
Other comprehensive income (loss)	(893)				66	(959)
Issuances of common stock, and related tax effects (in shares)		6
Issuances of common stock, and related tax effects	0	$ 0	0
Share-based compensation, and related tax benefits	206		206
Common share repurchases (in shares)		(8)
Common share repurchases	(896)	$ 0	(157)	(739)
Cash dividends paid on common shares	(357)			(357)
Redeemable noncontrolling interests fair value and other adjustments	(49)		(49)
Balance (in shares) at Mar. 31, 2015		952
Balance at Mar. 31, 2015	$ 31,878	$ 10	0	34,153	289	(2,574)	0
Balance (in shares) at Dec. 31, 2015	953	953
Balance at Dec. 31, 2015	$ 33,725	$ 10	29	37,125	56	(3,390)	(105)
Adjustment to adopt ASU 2016-09	28			28
Net earnings attributable to UnitedHealth Group common shareholders	1,611			1,611
Net earnings attributable to nonredeemable noncontrolling interest							11
Net Earnings, Including Portion Attributable to Nonredeemable Noncontrolling Interest	1,622
Other comprehensive income (loss)	530				142	388
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			150
Share-based compensation, and related tax benefits	150
Stock Repurchased and Retired During Period, Shares		4
Common share repurchases	(500)	$ 0	(176)	(324)
Cash dividends paid on common shares	(477)			(477)
Redeemable noncontrolling interests fair value and other adjustments	(59)		(59)
Distribution to nonredeemable noncontrolling interest	$ (8)						(8)
Balance (in shares) at Mar. 31, 2016	954	954
Balance at Mar. 31, 2016	$ 35,067	$ 10	$ 0	$ 37,963	$ 198	$ (3,002)	$ (102)