Shareholders' Equity Comprehensive Income (Loss) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Net unrealized gains on securities, before tax [Abstract]
Net unrealized gains (losses) on securities arising during the period, before tax	[1]	$ (1,195)	$ 657
Reclassification of net (gains) losses on securities included in net income, before tax	[2]	8	(5)
Impact of DAC, DSIC, unearned revenue, benefit reserves and reinsurance recoverables, before tax		508	(240)
Net unrealized gains (losses) on securities, before tax		(679)	412
Net unrealized gains on derivatives, before tax [Abstract]
Reclassification of net (gains) losses on derivatives included in net income, before tax	[3]	0	(1)
Net unrealized gains (losses) on derivatives, before tax		0	(1)
Foreign currency translation, before tax		(34)	6
Total other comprehensive income (loss), before tax		(713)	417
Net unrealized gains (losses) on securities, tax impact [Abstract]
Net unrealized gains (losses) on securities arising during the period, tax	[1]	264	(141)
Reclassification of net (gains) losses on securities included in net income, tax		(2)	1
Impact of DAC, DSIC, unearned revenue, benefit reserves and reinsurance recoverables, tax		(107)	50
Net unrealized gains (losses) on securities, tax		155	(90)
Net unrealized losses on derivatives, tax impact [Abstract]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax		0	0
Net unrealized gains (losses) on derivatives, tax		0	0
Foreign currency translation, tax		1	(1)
Total other comprehensive income (loss), tax		156	(91)
Net unrealized gains (losses) on securities, net of tax [Abstract]
Net unrealized gains (losses) on securities arising during the period, net of tax	[1]	(931)	516
Reclassification of net (gains) losses on securities included in net income, net of tax		6	(4)
Impact of DAC, DSIC, unearned revenue, benefit reserves and reinsurance recoverables, net of tax		401	(190)
Net unrealized gains (losses) on securities, net of tax		(524)	322
Net unrealized losses on derivatives, net of tax [Abstract]
Reclassification of net (gains) losses on derivatives included in net income, net of tax		0	(1)
Net unrealized gains (losses) on derivatives, net of tax		0	(1)
Foreign currency translation adjustment, net of tax		(33)	5
Total other comprehensive income (loss), net of tax		(557)	326
Interest Expense, Borrowings [Member]
Gain (Loss) Reclassified from Accumulated OCI into Income		$ 0	$ 1

[1] Includes impairments on Available-for-Sale securities related to factors other than credit that were recognized in OCI during the period.

[2] Reclassification amounts are recorded in net investment income.

[3] Includes nil and $1 million pretax gain reclassified to interest and debt expense for the three months ended March 31, 2020 and 2019, respectively.