Fair Values of Assets and Liabilities (Financial Instruments not at FV) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Financial Assets
Mortgage loans, net	$ 2,653	$ 2,655
Policy loans	869	867
Other investments	723	734
Other receivables	1,682	1,713
Financial Liabilities
Short-term borrowings	200	201
Line of credit with Ameriprise Financial	0	50
Other liabilities	6,874	5,427
Separate account liabilities - investment contracts	70,842	82,425
Carrying value [Member]
Financial Assets
Mortgage loans, net	2,653	2,655
Policy loans	869	867
Other investments	418	410
Other receivables	1,484	1,514
Financial Liabilities
Policyholder account balances, future policy benefits and claims	9,075	9,110
Short-term borrowings	200	201
Line of credit with Ameriprise Financial		50
Other liabilities	17	22
Separate account liabilities - investment contracts	269	340
Recurring basis [Member]
Financial Assets
Mortgage loans, net	2,617	2,707
Policy loans	810	810
Other investments	377	410
Other receivables	1,647	1,648
Financial Liabilities
Policyholder account balances, future policy benefits and claims	9,884	10,061
Short-term borrowings	201	201
Line of credit with Ameriprise Financial		50
Other liabilities	16	21
Separate account liabilities - investment contracts	269	340
Recurring basis [Member] | Level 2 [Member]
Financial Assets
Other investments	265	376
Financial Liabilities
Short-term borrowings	201	201
Separate account liabilities - investment contracts	269	340
Recurring basis [Member] | Level 3 [Member]
Financial Assets
Mortgage loans, net	2,617	2,707
Policy loans	810	810
Other investments	112	34
Other receivables	1,647	1,648
Financial Liabilities
Policyholder account balances, future policy benefits and claims	9,884	10,061
Line of credit with Ameriprise Financial		50
Other liabilities	$ 16	$ 21