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, 2019	Mar. 31, 2018
Numerator:
Net income	$ 395	$ 594
Denominator:
Basic: Weighted-average common shares outstanding	138.8	149.5
Effect of potentially dilutive nonqualified stock options and other share-based awards (in shares)	1.3	2.6
Diluted: Weighted-average common shares outstanding	140.1	152.1
Basic:
Net income (in dollars per share)	$ 2.85	$ 3.97
Diluted:
Net income (in dollars per share)	$ 2.82	$ 3.91
Effect of potentially dilutive nonqualified stock options and other share-based awards (in shares)	4.4	1.1