Earnings per Share Attributable to Ameriprise Financial, Inc. Common Shareholders (Basic & Diluted) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2020		Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Numerator:
Net income	$ (140)		$ 543	$ 1,357	$ 1,430
Denominator:
Basic: Weighted-average common shares outstanding	123.0		132.7	124.8	135.8
Effect of potentially dilutive nonqualified stock options and other share-based awards (in shares)	1.9		1.8	1.7	1.7
Diluted: Weighted-average common shares outstanding	124.9		134.5	126.5	137.5
Basic:
Net income (in dollars per share)	$ (1.14)		$ 4.09	$ 10.87	$ 10.53
Diluted:
Net income (in dollars per share)	$ (1.14)	[1]	$ 4.04	$ 10.73	$ 10.40
Options excluded from earnings per share calculation due to their anti-dilutive effect (in shares)				1.5	1.0

[1] Diluted shares used in this calculation represent basic shares due to the net loss. Using actual diluted shares would result in anti-dilution.