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
	Mar. 31, 2018	Mar. 31, 2017
Numerator:
Net income	$ 594	$ 403
Denominator:
Basic: Weighted-average common shares outstanding	149.5	157.5
Effect of potentially dilutive nonqualified stock options and other share-based awards (in shares)	2.6	2.6
Diluted: Weighted-average common shares outstanding	152.1	160.1
Basic:
Net income (in dollars per share)	$ 3.97	$ 2.56
Diluted:
Net income (in dollars per share)	$ 3.91	$ 2.52
Effect of potentially dilutive nonqualified stock options and other share-based awards (in shares)	1.1	2.5