Shareholders' Equity Changes in Stockholders' Equity (Details) - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Sep. 30, 2020
Stock repurchase program, authorized amount				$ 2,500
Remaining balance under stock repurchase program	$ 2,300
Number of shares reacquired through surrender of restricted shares	0.3	0.3	0.3
Value of shares reacquired through surrender of restricted shares	$ 52	$ 34	$ 44
Number of shares reacquired through net settlement of options	1.5	0.7	0.5
Aggregate value of shares reacquired through net settlement of options	$ 263	$ 106	$ 85
Treasury shares reissued for restricted stock award grants and Ameriprise Financial Franchise Advisor Deferred Compensation Plan	0.5	0.7	0.8
Open Market Share Repurchases [Member]
Repurchase of common shares (in shares)	8.4	13.4	11.3
Repurchase of common shares	$ 1,300	$ 1,900	$ 1,600