CONSOLIDATED STATEMENTS OF SHAREHOLDER'S EQUITY - USD ($) $ in Millions	Total	Common shares [Member]	Additional paid-in capital [Member]	Retained earnings [Member]	Accumulated other comprehensive income (loss) [Member]
Increase (Decrease) in Stockholders' Equity
Cumulative effect of change in accounting policy | Cumulative effect of adoption of premium amortization on purchased callable debt securities guidance [Member]	$ (2)			$ (2)
Beginning balance at Dec. 31, 2018	3,572	$ 3	$ 2,466	1,058	$ 45
Comprehensive income:
Net Income	145			145
Other comprehensive income (loss), net of tax	272				272
Total comprehensive income	417
Cash dividends to Ameriprise Financial, Inc.	(250)			(250)
Ending balance at Mar. 31, 2019	3,737	3	2,466	951	317
Increase (Decrease) in Stockholders' Equity
Cumulative effect of change in accounting policy | Cumulative effect of adoption of current expected credit losses guidance [Member]	(7)			(7)
Beginning balance at Dec. 31, 2019	3,336	3	2,466	293	574
Comprehensive income:
Net Income	1,794			1,794
Other comprehensive income (loss), net of tax	(395)				(395)
Total comprehensive income	1,399
Cash dividends to Ameriprise Financial, Inc.	(250)			(250)
Ending balance at Mar. 31, 2020	$ 4,478	$ 3	$ 2,466	$ 1,830	$ 179