Investments - Rollforward of Allowance for Credit Losses (Details) - Ameriprise Financial - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Rollforward of Available-for-Sale securities allowance for credit losses
Beginning balance	$ 5	$ 5
Reductions for securities sold during the period (realized)	(4)
Additional increases (decreases) on securities that had an allowance recorded in a previous period		0
Ending balance	1	5
Corporate debt securities
Rollforward of Available-for-Sale securities allowance for credit losses
Beginning balance	0
Ending balance	0
Commercial mortgage backed securities
Rollforward of Available-for-Sale securities allowance for credit losses
Beginning balance	4	4
Reductions for securities sold during the period (realized)	(4)
Additional increases (decreases) on securities that had an allowance recorded in a previous period		0
Ending balance	0	4
State and municipal obligations
Rollforward of Available-for-Sale securities allowance for credit losses
Beginning balance	1	1
Reductions for securities sold during the period (realized)	0
Additional increases (decreases) on securities that had an allowance recorded in a previous period		0
Ending balance	$ 1	$ 1

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Amount excluding accrued interest, of allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479130/326-30-45-1

+ Details

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- Definition

Amount, excluding accrued interest, of credit loss expense (reversal of expense) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) with previously recorded allowance and not intended to be sold and not more likely than not will be required to sell before recovery of amortized cost basis.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479106/326-30-50-9

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476148/220-40-50-22

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- Definition

Amount, excluding accrued interest, of decrease in allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) from sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479106/326-30-50-9

+ Details

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