Reserve for Life-Contingent Contract Benefits and Contractholder Funds (Details 5) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Movement in Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross [Roll Forward]
Balance at beginning of period	$ 366	$ 350
Less reinsurance recoverables	222	234
Net balance at beginning of period	144	116
Incurred guarantee benefits	37	28
Paid guarantee benefits	0	0
Net change	37	28
Net balance at end of period	181	144
Plus reinsurance recoverables	184	222
Balance at end of period	365	366
Liability for guarantees related to death benefits and interest-sensitive life products
Movement in Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross [Roll Forward]
Balance at beginning of period	223	195
Less reinsurance recoverables	106	98
Net balance at beginning of period	117	97
Incurred guarantee benefits	26	20
Paid guarantee benefits	0	0
Net change	26	20
Net balance at end of period	143	117
Plus reinsurance recoverables	101	106
Balance at end of period	244	223
Liability for guarantees related to income benefits
Movement in Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross [Roll Forward]
Balance at beginning of period	68	95
Less reinsurance recoverables	64	91
Net balance at beginning of period	4	4
Incurred guarantee benefits	0	0
Paid guarantee benefits	0	0
Net change	0	0
Net balance at end of period	4	4
Plus reinsurance recoverables	40	64
Balance at end of period	44	68
Liability for guarantees related to accumulation and withdrawal benefits
Movement in Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross [Roll Forward]
Balance at beginning of period	75	60
Less reinsurance recoverables	52	45
Net balance at beginning of period	23	15
Incurred guarantee benefits	11	8
Paid guarantee benefits	0	0
Net change	11	8
Net balance at end of period	34	23
Plus reinsurance recoverables	43	52
Balance at end of period	$ 77	$ 75