Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Pre-tax
Other comprehensive income (loss)	$ (1,879)	$ (1,763)
Tax
Other comprehensive income (loss)	398	371
After-tax
Other comprehensive income (loss)	(1,481)	(1,392)
Unrealized net capital gains and losses
Pre-tax
Unrealized net holding gains and losses arising during the period, net of related offsets	(1,718)	(1,433)
Less: reclassification adjustment of realized capital gains and losses	185	287
Other comprehensive income (loss)	(1,903)	(1,720)
Tax
Unrealized net holding gains and losses arising during the period, net of related offsets	364	303
Less: reclassification adjustment of realized capital gains and losses	(39)	(60)
Other comprehensive income (loss)	403	363
After-tax
Unrealized net holding gains and losses arising during the period, net of related offsets	(1,354)	(1,130)
Less: reclassification adjustment of realized capital gains and losses	146	227
Other comprehensive income (loss)	(1,500)	(1,357)
Unrealized foreign currency translation adjustments
Pre-tax
Other comprehensive income (loss)	43	(49)
Tax
Other comprehensive income (loss)	(9)	10
After-tax
Other comprehensive income (loss)	34	(39)
Unamortized pension and other postretirement prior service credit
Pre-tax
Other comprehensive income (loss)	(19)	6
Tax
Other comprehensive income (loss)	4	(2)
After-tax
Other comprehensive income (loss)	$ (15)	$ 4