Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Millions	Total	Common Stock	Capital In Excess of Par Value	Retained Earnings	Accumulated Other Comprehensive Income (loss)	Treasury Stock	Noncontrolling Interests
Balances (in shares) at Dec. 31, 2020		198,649
Balances at Dec. 31, 2020	$ 13,728	$ 33	$ 2,705	$ 20,517	$ 391	$ (9,918)	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to Humana	828			828
Other comprehensive loss	(283)				(283)
Common stock repurchases	(30)					(30)
Dividends and dividend equivalents	(93)			(93)
Stock-based compensation	39		39
Restricted stock unit vesting	0		(33)			33
Stock option exercises	1		1			0
Balances (in shares) at Mar. 31, 2021		198,649
Balances at Mar. 31, 2021	14,190	$ 33	2,712	21,252	108	(9,915)	0
Balances (in shares) at Dec. 31, 2021		198,649
Balances at Dec. 31, 2021	16,103	$ 33	3,082	23,086	42	(10,163)	23
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to Humana	930			930
Other comprehensive loss	(614)				(614)
Common stock repurchases	(1,024)					(1,024)
Dividends and dividend equivalents	(101)			(101)
Stock-based compensation	43		43
Restricted stock unit vesting	0		(24)			24
Stock option exercises	5		2			3
Balances (in shares) at Mar. 31, 2022		198,649
Balances at Mar. 31, 2022	$ 15,342	$ 33	$ 3,103	$ 23,915	$ (572)	$ (11,160)	$ 23