Shareholders' Equity Comprehensive Income (Loss) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Net unrealized gains on securities, before tax [Abstract]
Net unrealized gains (losses) on securities arising during the period, before tax	[1]	$ 512	$ (266)	$ 1,169	$ (818)
Reclassification of net (gains) losses on securities included in net income, before tax	[2]	0	(5)	(5)	(10)
Impact of DAC, DSIC, unearned revenue, benefit reserves and reinsurance recoverables, before tax		(259)	103	(499)	319
Net unrealized gains (losses) on securities, before tax		253	(168)	665	(509)
Net unrealized gains on derivatives, before tax [Abstract]
Reclassification of net (gains) losses on derivatives included in net income, before tax	[3]	0	0	(1)	0
Net unrealized gains (losses) on derivatives, before tax		0	0	(1)	0
Foreign currency translation, before tax		(15)	(46)	(9)	(16)
Total other comprehensive income (loss), before tax		238	(214)	655	(525)
Net unrealized gains (losses) on securities, tax impact [Abstract]
Net unrealized gains (losses) on securities arising during the period, tax	[1]	(60)	59	(201)	182
Reclassification of net (gains) losses on securities included in net income, tax		0	1	1	2
Impact of DAC, DSIC, unearned revenue, benefit reserves and reinsurance recoverables, tax		55	(22)	105	(67)
Net unrealized gains (losses) on securities, tax		(5)	38	(95)	117
Net unrealized losses on derivatives, tax impact [Abstract]
Reclassification of net (gains) losses on derivatives included in net income, tax		0	0	0	0
Net unrealized gains (losses) on derivatives, tax		0	0	0	0
Foreign currency translation, tax		1	2	0	1
Total other comprehensive income (loss), tax		(4)	40	(95)	118
Net unrealized gains (losses) on securities, net of tax [Abstract]
Net unrealized gains (losses) on securities arising during the period, net of tax	[1]	452	(207)	968	(636)
Reclassification of net (gains) losses on securities included in net income, net of tax		0	(4)	(4)	(8)
Impact of DAC, DSIC, unearned revenue, benefit reserves and reinsurance recoverables, net of tax		(204)	81	(394)	252
Net unrealized gains (losses) on securities, net of tax		248	(130)	570	(392)
Net unrealized losses on derivatives, net of tax [Abstract]
Reclassification of net (gains) losses on derivatives included in net income, net of tax		0	0	(1)	0
Net unrealized gains (losses) on derivatives, net of tax		0	0	(1)	0
Foreign currency translation adjustment, net of tax		(14)	(44)	(9)	(15)
Total other comprehensive income (loss), net of tax		234	(174)	560	(407)
Interest Expense, Borrowings [Member]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net		0	1	1	1
Net investment income [Member]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net		$ 0	$ 1	$ 0	$ 1

[1] 1) Includes OTTI losses on Available-for-Sale securities related to factors other than credit that were recognized in other comprehensive income (loss) during the period.

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

[3] ⁽³⁾ Includes nil and a $1 million pretax gain reclassified to interest and debt expense for the three months ended June 30, 2019 and 2018, respectively, and nil and a $1 million pretax loss reclassified to net investment income for the three months ended June 30, 2019 and 2018, respectively