Equity (Reclassifications Out of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment gains (losses)	$ 134	$ (288)
Net investment income	5,314	3,061
Net derivative gains (losses)	(2,235)	4,201
Other expenses	3,150	3,273
Income (loss) from continuing operations before provision for income tax	291	5,643
Income tax (expense) benefit	72	(1,242)
Net income (loss)	363	4,401
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income (loss)	(172)	(220)
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)	(49)	204
Net investment income	(5)	(11)
Net derivative gains (losses)	24	(6)
Income (loss) from continuing operations before provision for income tax	(30)	187
Income tax (expense) benefit	7	(48)
Net income (loss)	(23)	139
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	(174)	(438)
Income tax (expense) benefit	37	96
Net income (loss)	(137)	(342)
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)	29	6
Net investment income	12	6
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)	(219)	(451)
Net investment income	3	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)	(18)	(26)
Amortization of prior service (costs) credit	4	5
Income (loss) from continuing operations before provision for income tax	(14)	(21)
Income tax (expense) benefit	2	4
Net income (loss)	$ (12)	$ (17)