Investments (Rating info) (Details) - Ameriprise Financial [Member] $ in Millions		Sep. 30, 2019 USD ($)	Dec. 31, 2018 USD ($)
Investments
Fixed Maturity Investments Rated Internally		$ 609	$ 755
Percentage of GNMA, FNMA and FHLMC securities rated AAA		41.00%	36.00%
Number of holdings of other than GNMA, FNMA, and FHLMC having greater than 10% of total equity		0	0
AAA [Member]
Investments
Amortized cost		$ 15,675	$ 13,399
Fair value		$ 15,916	$ 13,252
Percent of total fair value		51.00%	43.00%
AA [Member]
Investments
Amortized cost		$ 1,080	$ 1,571
Fair value		$ 1,291	$ 1,723
Percent of total fair value		4.00%	5.00%
A [Member]
Investments
Amortized cost		$ 3,020	$ 3,667
Fair value		$ 3,498	$ 3,899
Percent of total fair value		11.00%	13.00%
BBB [Member]
Investments
Amortized cost		$ 8,542	$ 11,102
Fair value		$ 9,441	$ 11,290
Percent of total fair value		31.00%	36.00%
Below investment grade [Member]
Investments
Amortized cost	[1]	$ 795	$ 932
Fair value	[1]	$ 821	$ 894
Percent of total fair value		3.00%	3.00%
Total fixed maturities [Member]
Investments
Amortized cost		$ 29,112	$ 30,671
Fair value		$ 30,967	$ 31,058
Percent of total fair value		100.00%	100.00%
Interest in CLOs managed by the Company [Member] | Below investment grade [Member]
Investments
Amortized cost		$ 4	$ 5
Fair value		$ 6	$ 6

[1] The amortized cost and fair value of below investment grade securities includes interest in CLOs managed by the Company of $4 million and $6 million, respectively, at September 30, 2019, and $5 million and $6 million, respectively, at December 31, 2018. These securities are not rated but are included in below investment grade due to their risk characteristics.