Segment Information (Operating Results) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	$ (229)	$ (455)	$ (253)	$ (1,065)
Provision for income tax expense (benefit)	(65)	(191)	(87)	(436)
Net investment gains (losses)	(74)	0	(78)	(55)
Net derivative gains (losses)	(278)	(89)	(565)	(902)
Other adjustments to net income	70	137	149	199
Net income (loss)	(164)	(264)	(166)	(629)
Annuities
Segment Reporting Information [Line Items]
Interest revenue	374	308	733	632
Interest expense	0	0	0	0
Life
Segment Reporting Information [Line Items]
Interest revenue	92	74	180	154
Interest expense	0	0	0	0
Run-off
Segment Reporting Information [Line Items]
Interest revenue	314	338	657	712
Interest expense	0	4	0	19
Corporate & Other
Segment Reporting Information [Line Items]
Interest revenue	7	46	17	102
Interest expense	1	19	2	37
Operating Segments
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	235	(261)	601	18
Provision for income tax expense (benefit)	33	(122)	93	(58)
Adjusted earnings	202	(139)	508	76
Operating Segments | Annuities
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	255	264	510	529
Provision for income tax expense (benefit)	43	65	87	132
Adjusted earnings	212	199	423	397
Operating Segments | Life
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	26	84	90	(42)
Provision for income tax expense (benefit)	6	16	18	(16)
Adjusted earnings	20	68	72	(26)
Operating Segments | Run-off
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	(8)	(597)	56	(484)
Provision for income tax expense (benefit)	(2)	(196)	11	(171)
Adjusted earnings	(6)	(401)	45	(313)
Operating Segments | Corporate & Other
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	(38)	(12)	(55)	15
Provision for income tax expense (benefit)	(14)	(7)	(23)	(3)
Adjusted earnings	(24)	(5)	(32)	18
Segment Reconciling Items
Segment Reporting Information [Line Items]
Provision for income tax expense (benefit)	98	69	180	378
Net investment gains (losses)	(74)	0	(78)	(55)
Net derivative gains (losses)	(278)	(89)	(565)	(902)
Other adjustments to net income	$ (112)	$ (105)	$ (211)	$ (126)