Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Pre- tax
Other comprehensive income (loss)	$ 200	$ (67)	$ 847	$ (355)
Tax
Other comprehensive income (loss)	(42)	14	(178)	75
After- tax
Other comprehensive income (loss), after-tax	158	(53)	669	(280)
Accumulated Net Investment Gain (Loss)
Pre- tax
Unrealized net holding gains and losses arising during the period, net of related offsets	216	(64)	863	(379)
Less: reclassification adjustment of realized capital gains and losses	17	(8)	11	(24)
Other comprehensive income (loss)	199	(56)	852	(355)
Tax
Unrealized net holding gains and losses arising during the period, net of related offsets	(46)	14	(181)	80
Less: reclassification adjustment of realized capital gains and losses	(4)	2	(2)	5
Other comprehensive income (loss)	(42)	12	(179)	75
After- tax
Unrealized net holding gains and losses arising during the period, net of related offsets	170	(50)	682	(299)
Less: reclassification adjustment of realized capital gains and losses	13	(6)	9	(19)
Other comprehensive income (loss), after-tax	157	(44)	673	(280)
Accumulated Foreign Currency Adjustment
Pre- tax
Other comprehensive income (loss)	1	(11)	(5)	0
Tax
Other comprehensive income (loss)	0	2	1	0
After- tax
Other comprehensive income (loss), after-tax	$ 1	$ (9)	$ (4)	$ 0

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