Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Pre-tax
Other comprehensive income (loss)	$ 591	$ 2,624	$ (1,288)	$ 861
Tax
Other comprehensive income (loss)	(124)	(554)	274	(183)
After-tax
Other comprehensive income (loss)	467	2,070	(1,014)	678
Unrealized net capital gains and losses
Pre-tax
Unrealized net holding gains and losses arising during the period, net of related offsets	706	2,796	(1,007)	1,363
Less: reclassification adjustment of realized capital gains and losses	93	169	283	456
Other comprehensive income (loss)	613	2,627	(1,290)	907
Tax
Unrealized net holding gains and losses arising during the period, net of related offsets	(149)	(590)	215	(288)
Less: reclassification adjustment of realized capital gains and losses	(20)	(35)	(59)	(96)
Other comprehensive income (loss)	(129)	(555)	274	(192)
After-tax
Unrealized net holding gains and losses arising during the period, net of related offsets	557	2,206	(792)	1,075
Less: reclassification adjustment of realized capital gains and losses	73	134	224	360
Other comprehensive income (loss)	484	2,072	(1,016)	715
Unrealized foreign currency translation adjustments
Pre-tax
Other comprehensive income (loss)	(4)	11	39	(38)
Tax
Other comprehensive income (loss)	1	(2)	(8)	8
After-tax
Other comprehensive income (loss)	(3)	9	31	(30)
Unamortized pension and other postretirement prior service credit
Pre-tax
Other comprehensive income (loss)	(18)	(14)	(37)	(8)
Tax
Other comprehensive income (loss)	4	3	8	1
After-tax
Other comprehensive income (loss)	$ (14)	$ (11)	$ (29)	$ (7)