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)			$ (7)
Beginning balance at Dec. 31, 2018	3,572	$ 3	$ 2,466	293	$ 574
Comprehensive income:
Net Income	355			1,001
Other comprehensive income (loss), net of tax	480				131
Total comprehensive income	835
Cash dividends to Ameriprise Financial, Inc.	(550)			(500)
Ending balance at Jun. 30, 2019	3,855	3	2,466	861	525
Beginning balance at Mar. 31, 2019	3,737	3	2,466	951	317
Comprehensive income:
Net Income	210			210
Other comprehensive income (loss), net of tax	208				208
Total comprehensive income	418
Cash dividends to Ameriprise Financial, Inc.	(300)			(300)
Ending balance at Jun. 30, 2019	3,855	3	2,466	861	525
Increase (Decrease) in Stockholders' Equity
Cumulative effect of change in accounting policy | Cumulative effect of adoption of current expected credit losses guidance [Member]	(7)			(2)
Beginning balance at Dec. 31, 2019	3,336	3	2,466	1,058	45
Comprehensive income:
Net Income	1,001			355
Other comprehensive income (loss), net of tax	131				480
Total comprehensive income	1,132
Cash dividends to Ameriprise Financial, Inc.	(500)			(550)
Ending balance at Jun. 30, 2020	3,961	3	2,466	787	705
Beginning balance at Mar. 31, 2020	4,478	3	2,466	1,830	179
Comprehensive income:
Net Income	(793)			(793)
Other comprehensive income (loss), net of tax	526				526
Total comprehensive income	(267)
Cash dividends to Ameriprise Financial, Inc.	(250)			(250)
Ending balance at Jun. 30, 2020	$ 3,961	$ 3	$ 2,466	$ 787	$ 705