Shareholder's Equity (Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax, Portion Attributable to Parent [Abstract]
Net unrealized gains (losses) on securities arising during the period, pretax	[1]	$ (1,002)	$ 599
Reclassification of net (gains) losses on securities included in net income, pretax	[2]	(8)	(10)
Impact of DAC, DSIC, unearned revenue, benefit reserves and reinsurance recoverables, pretax		508	(240)
Net unrealized gains (losses) on securities, pretax		(502)	349
Total other comprehensive income (loss), pretax		(502)	349
Other Comprehensive Income (Loss), Available-for-sale Securities, Tax, Portion Attributable to Parent [Abstract]
Net unrealized gains (losses) on securities arising during the period, tax	[1]	212	(129)
Reclassification of net (gains) losses on securities included in net income, tax		2	2
Impact of DAC, DSIC, unearned revenue, benefit reserves and reinsurance recoverables, tax		(107)	50
Net unrealized gains (losses) on securities, tax		107	(77)
Total other comprehensive income (loss), tax		107	(77)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent [Abstract]
Net unrealized gains (losses) on securities arising during the period, net of tax	[1]	(790)	470
Reclassification of net (gains) losses on securities included in net income, net of tax		(6)	(8)
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		(395)	272
Total other comprehensive income (loss), net of tax		$ (395)	$ 272

[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 realized investment gains (losses).