Variable Annuity and Insurance Guarantees (Liability Rollforward) (Details) - USD ($) $ in Millions		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019
GMDB and GGU [Member]
Changes in Additional Liabilities for Variable Annuity and Insurance Guarantees
Beginning Balance		$ 16	$ 19
Incurred claims		10
Paid claims		(6)	(4)
Ending Balance		20	15
GMIB [Member]
Changes in Additional Liabilities for Variable Annuity and Insurance Guarantees
Beginning Balance		7	8
Incurred claims		1	(1)
Paid claims		(1)
Ending Balance		7	7
GMWB [Member]
Changes in Additional Liabilities for Variable Annuity and Insurance Guarantees
Beginning Balance		1,462	875
Incurred claims	[1]	2,219	1,245
Ending Balance		3,681	2,120
GMAB [Member]
Changes in Additional Liabilities for Variable Annuity and Insurance Guarantees
Beginning Balance		(39)	(19)
Incurred claims	[1]	63
Ending Balance		24	(19)
UL [Member]
Changes in Additional Liabilities for Variable Annuity and Insurance Guarantees
Beginning Balance		758	659
Incurred claims		172	110
Paid claims		(34)	(34)
Ending Balance		$ 896	$ 735

[1] The incurred claims for GMWB and GMAB include the change in the fair value of the liabilities (contra liabilities) less paid claims.