Equity (Reclassifications Out of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gain (Loss) on Investments	$ (34)		$ 63		$ (53)	$ 52
Net investment income	652		942		1,568	1,753
Gain (Loss) on Derivative Instruments, Net, Pretax	(2,653)		149		4,249	(1,154)
Income (loss) before provision for income tax	(2,522)		469		3,730	(484)
Income tax (expense) benefit	531		(85)		(762)	133
Net income (loss)	(1,991)	$ 4,959	384	$ (735)	2,968	(351)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income (loss)	(16)		56		(5)	61
Reclassification out of Accumulated Other Comprehensive Income [Member] | Net unrealized investment gains (losses):
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gain (Loss) on Investments	(20)		70		(7)	55
Gain (Loss) on Derivative Instruments, Net, Pretax	(3)		(22)		(5)	(26)
Income (loss) before provision for income tax	(23)		48		(12)	29
Income tax (expense) benefit	5		(10)		3	(6)
Net income (loss)	(18)		38		(9)	23
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized gains (losses) on derivatives - cash flow hedges:
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) before provision for income tax	3		22		5	48
Income tax (expense) benefit	(1)		(4)		(1)	(10)
Net income (loss)	2		18		4	38
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized gains (losses) on derivatives - cash flow hedges: | Interest rate swaps
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment income	0		0		1	1
Gain (Loss) on Derivative Instruments, Net, Pretax	0		6		1	28
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized gains (losses) on derivatives - cash flow hedges: | Foreign currency swaps
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gain (Loss) on Derivative Instruments, Net, Pretax	$ 3		$ 16		$ 3	$ 19