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		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Numerator:
Net income	$ 462	$ 393	$ 1,056	$ 796
Denominator:
Basic: Weighted-average common shares outstanding	147.0	155.1	148.2	156.3
Effect of potentially dilutive nonqualified stock options and other share-based awards (in shares)	2.0	2.4	2.3	2.5
Diluted: Weighted-average common shares outstanding	149.0	157.5	150.5	158.8
Basic:
Net income (in dollars per share)	$ 3.14	$ 2.53	$ 7.13	$ 5.09
Diluted:
Net income (in dollars per share)	$ 3.10	$ 2.50	$ 7.02	$ 5.01
Effect of potentially dilutive nonqualified stock options and other share-based awards (in shares)			1.1	2.6