Segment Information (Operating Results) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	$ (407)	$ (122)	$ (660)	$ (1,187)
Provision for income tax expense (benefit)	(108)	567	(195)	131
Net investment gains (losses)	(42)	21	(120)	(34)
Net derivative gains (losses)	(665)	(162)	(1,230)	(1,064)
Other adjustments to net income	73	64	222	263
Net income (loss)	(299)	(689)	(465)	(1,318)
Annuities
Segment Reporting Information [Line Items]
Interest revenue	395	306	1,128	938
Interest expense	0	0	0	0
Life
Segment Reporting Information [Line Items]
Interest revenue	96	76	276	230
Interest expense	0	(4)	0	(4)
Run-off
Segment Reporting Information [Line Items]
Interest revenue	322	349	979	1,061
Interest expense	0	4	0	23
Corporate & Other
Segment Reporting Information [Line Items]
Interest revenue	12	20	29	122
Interest expense	0	0	2	37
Operating Segments
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	266	511	867	529
Provision for income tax expense (benefit)	32	1,215	125	1,157
Adjusted earnings	234	(704)	742	(628)
Operating Segments \| Annuities
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	469	441	979	970
Provision for income tax expense (benefit)	81	128	168	260
Adjusted earnings	388	313	811	710
Operating Segments \| Life
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	52	(16)	142	(58)
Provision for income tax expense (benefit)	10	(11)	28	(27)
Adjusted earnings	42	(5)	114	(31)
Operating Segments \| Run-off
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	(135)	144	(79)	(340)
Provision for income tax expense (benefit)	(29)	41	(18)	(130)
Adjusted earnings	(106)	103	(61)	(210)
Operating Segments \| Corporate & Other
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	(120)	(58)	(175)	(43)
Provision for income tax expense (benefit)	(30)	1,057	(53)	1,054
Adjusted earnings	(90)	(1,115)	(122)	(1,097)
Segment Reconciling Items
Segment Reporting Information [Line Items]
Provision for income tax expense (benefit)	140	648	320	1,026
Net investment gains (losses)	(42)	21	(120)	(34)
Net derivative gains (losses)	(665)	(162)	(1,230)	(1,064)
Other adjustments to net income	$ 34	$ (492)	$ (177)	$ (618)

Aggregate net gain (loss) on all derivative instruments recognized in earnings during the period, before tax effects.

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