Equity (Reclassifications Out of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment gains (losses)	$ 266	$ (133)	$ 281	$ 153
Net derivative gains (losses)	(2,099)	(912)	(764)	(91)
Net investment income	4,887	4,947	9,446	10,408
Other expenses	(3,246)	(4,072)	(7,438)	(8,132)
Income (loss) from continuing operations before provision for income tax	(100)	1,113	2,822	4,172
Provision for income tax expense (benefit)	214	6	(505)	(890)
Net income (loss)	114	1,119	2,317	3,282
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income (loss)	(87)	282	105	(35)
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Investment Gains (Losses), Net of Related Offsets
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment gains (losses)	158	110	125	249
Net derivative gains (losses)	9	50	22	(16)
Net investment income	16	17	19	57
Income (loss) from continuing operations before provision for income tax	183	177	166	290
Provision for income tax expense (benefit)	(61)	(65)	(54)	(100)
Net income (loss)	122	112	112	190
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Gains (Losses) on Derivatives
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) from continuing operations before provision for income tax	(243)	303	80	(251)
Provision for income tax expense (benefit)	68	(95)	(25)	101
Net income (loss)	(175)	208	55	(150)
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Gains (Losses) on Derivatives | Interest rate swaps
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net derivative gains (losses)	18	7	28	12
Net investment income	4	3	7	6
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Gains (Losses) on Derivatives | Interest rate forwards
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net derivative gains (losses)	(1)	1	1	4
Net investment income	2	1	3	2
Other expenses	1	0	1	1
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Gains (Losses) on Derivatives | Foreign currency swaps
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net derivative gains (losses)	(269)	290	37	(277)
Net investment income	(1)	(1)	(1)	(1)
Other expenses	0	1	1	1
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Gains (Losses) on Derivatives | Credit forwards
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net derivative gains (losses)	3	0	3	0
Net investment income	0	1	0	1
Reclassification out of Accumulated Other Comprehensive Income | Defined Benefit Plans Adjustment
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of net actuarial gains (losses)	(52)	(58)	(103)	(116)
Amortization of prior service (costs) credit	1	1	4	2
Income (loss) from continuing operations before provision for income tax	(51)	(57)	(99)	(114)
Provision for income tax expense (benefit)	17	19	37	39
Net income (loss)	$ (34)	$ (38)	$ (62)	$ (75)