SCHEDULE I - PARENT COMPANY FINANCIAL INFORMATION (Condensed Statements of Comprehensive Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Condensed Financial Statements, Captions [Line Items]
Net income	$ 3,367	$ 2,707	$ 1,683
Other comprehensive income (loss):
Change in gross unrealized investment gains/losses	393	450	(189)
Effect of income taxes	(89)	(105)	51
Total change in unrealized investment gains/losses, net of tax	304	345	(138)
Reclassification adjustment for net realized gains included in investment income	(90)	(34)	(53)
Effect of income taxes	20	8	17
Total reclassification adjustment, net of tax	(70)	(26)	(36)
Other comprehensive income (loss), net of tax	234	319	(174)
Comprehensive income (loss) attributable to our equity method investment in Kindred at Home	1	(4)	(4)
Comprehensive income	3,602	3,022	1,505
Parent Company
Condensed Financial Statements, Captions [Line Items]
Net income	3,367	2,707	1,683
Other comprehensive income (loss):
Change in gross unrealized investment gains/losses	393	450	(189)
Effect of income taxes	(89)	(105)	51
Total change in unrealized investment gains/losses, net of tax	304	345	(138)
Reclassification adjustment for net realized gains included in investment income	(90)	(34)	(53)
Effect of income taxes	20	8	17
Total reclassification adjustment, net of tax	(70)	(26)	(36)
Other comprehensive income (loss), net of tax	234	319	(174)
Comprehensive income (loss) attributable to our equity method investment in Kindred at Home	1	(4)	(4)
Comprehensive income	$ 3,602	$ 3,022	$ 1,505