Equity (Reclassifications Out of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment gains (losses)	$ 15	$ 286
Net derivative gains (losses)	1,335	821
Net investment income	4,559	5,461
Other expenses	(4,192)	(4,060)
Income (loss) from continuing operations before provision for income tax	2,922	3,059
Provision for income tax expense (benefit)	(719)	(896)
Net income (loss)	2,203	2,163
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income (loss)	192	(317)
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)	(33)	139
Net derivative gains (losses)	13	(66)
Net investment income	3	40
Income (loss) from continuing operations before provision for income tax	(17)	113
Provision for income tax expense (benefit)	7	(35)
Net income (loss)	(10)	78
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	323	(554)
Provision for income tax expense (benefit)	(93)	196
Net income (loss)	230	(358)
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)	10	5
Net investment income	3	3
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)	2	3
Net investment income	1	1
Other expenses	0	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)	306	(567)
Other expenses	1	0
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)	(51)	(58)
Amortization of prior service (costs) credit	3	1
Income (loss) from continuing operations before provision for income tax	(48)	(57)
Provision for income tax expense (benefit)	20	20
Net income (loss)	$ (28)	$ (37)