Variable Annuity and Insurance Guarantees (Liability Rollforward) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
GMDB and GGU [Member]
Changes in Additional Liabilities for Variable Annuity and Insurance Guarantees
Balance, at the beginning of the period		$ 16	$ 14
Incurred claims		1	4
Paid claims		(1)	(4)
Balance, at the end of the period		16	14
GMIB [Member]
Changes in Additional Liabilities for Variable Annuity and Insurance Guarantees
Balance, at the beginning of the period		8	8
Paid claims		(1)
Balance, at the end of the period		7	8
GMWB [Member]
Changes in Additional Liabilities for Variable Annuity and Insurance Guarantees
Balance, at the beginning of the period	[1]	1,017	1,057
Incurred claims	[1]	(380)	649
Balance, at the end of the period	[1]	637	1,706
GMAB [Member]
Changes in Additional Liabilities for Variable Annuity and Insurance Guarantees
Balance, at the beginning of the period	[1]	(24)
Incurred claims	[1]	(29)	31
Balance, at the end of the period	[1]	(53)	31
UL [Member]
Changes in Additional Liabilities for Variable Annuity and Insurance Guarantees
Balance, at the beginning of the period		434	332
Incurred claims		23	22
Paid claims		(8)	(6)
Balance, at the end of the period		$ 449	$ 348

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