Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 1,531	$ 1,340	$ 2,947	$ 3,641
Other comprehensive income:
Change in gross unrealized investment (losses) gains	(63)	66	(247)	332
Effect of income taxes	14	(15)	56	(78)
Total change in unrealized investment (losses) gains, net of tax	(49)	51	(191)	254
Reclassification adjustment for net realized gains	(16)	(1)	(80)	(48)
Effect of income taxes	4	0	19	10
Total reclassification adjustment, net of tax	(12)	(1)	(61)	(38)
Other comprehensive (loss) gain, net of tax	(61)	50	(252)	216
Comprehensive (loss) income attributable to equity method investments	(10)	3	6	(2)
Comprehensive income (loss) attributable to noncontrolling interests	0	0	0	0
Comprehensive income attributable to Humana	$ 1,460	$ 1,393	$ 2,701	$ 3,855