Equity (Reclassifications Out of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment gains (losses)	$ (288)	$ 15
Net derivative gains (losses)	4,201	115
Net investment income	3,061	4,908
Other expenses	3,273	3,225
Income (loss) from continuing operations before provision for income tax	5,643	1,744
Income tax (expense) benefit	(1,242)	(359)
Net income (loss)	4,401	1,385
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income (loss)	(220)	(9)
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)	204	(24)
Net derivative gains (losses)	(6)	22
Net investment income	(11)	4
Income (loss) from continuing operations before provision for income tax	187	2
Income tax (expense) benefit	(48)	0
Net income (loss)	139	2
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	(438)	24
Income tax (expense) benefit	96	(12)
Net income (loss)	(342)	12
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Gains (Losses) on Derivatives | Interest Rate Contract
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment gains (losses)	6	(6)
Net investment income	6	5
Other expenses	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 investment gains (losses)	(451)	25
Net investment income	0	(2)
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Gains (Losses) on Derivatives | Credit
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment gains (losses)	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)	(26)	(36)
Amortization of prior service (costs) credit	5	7
Income (loss) from continuing operations before provision for income tax	(21)	(29)
Income tax (expense) benefit	4	6
Net income (loss)	$ (17)	$ (23)