Equity (Reclassifications Out of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment gains (losses)									$ (110)	$ 444	$ (298)
Net investment income									17,117	18,868	16,166
Net derivative gains (losses)									1,349	628	851
Other expenses									13,150	13,689	13,714
Income (loss) from continuing operations before provision for income tax									6,927	6,795	6,307
Income tax (expense) benefit									(1,509)	(886)	(1,179)
Net income (loss)	$ 158	$ 709	$ 150	$ 4,401	$ 588	$ 2,190	$ 1,746	$ 1,385	5,418	5,909	5,128
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income (loss)									866	399	(484)
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)									362	270	6
Net investment income									(24)	(30)	(1)
Net derivative gains (losses)									19	25	(19)
Income (loss) from continuing operations before provision for income tax									357	265	(14)
Income tax (expense) benefit									(83)	(61)	3
Net income (loss)									274	204	(11)
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									1,016	268	(517)
Income tax (expense) benefit									(358)	27	135
Net income (loss)									658	295	(382)
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Gains (Losses) on Derivatives | Interest rate contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment gains (losses)									121	4	0
Net investment income									36	23	20
Net derivative gains (losses)									0	0	21
Other expenses									2	2	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)									851	240	0
Net investment income									4	(4)	(5)
Net derivative gains (losses)									0	0	(558)
Other expenses									2	2	2
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Gains (Losses) on Derivatives | Credit derivatives
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment income									0	1	1
Net derivative gains (losses)									0	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)									(105)	(145)	(145)
Amortization of prior service (costs) credit									19	27	25
Income (loss) from continuing operations before provision for income tax									(86)	(118)	(120)
Income tax (expense) benefit									20	18	29
Net income (loss)									$ (66)	$ (100)	$ (91)