Investments - Rollforward of Allowance for Credit Losses (Details) - Ameriprise Financial - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Rollforward of Available-for-Sale securities allowance for credit losses
Beginning Balance	$ 5	$ 5	$ 5	$ 2
Additional increases (decreases) on securities that had an allowance recorded in a previous period	(1)	0	(1)
Additions for which credit losses were not previously recorded				4
Reductions for securities sold during the period (realized)				(1)
Ending Balance	4	5	4	5
Corporate debt securities
Rollforward of Available-for-Sale securities allowance for credit losses
Beginning Balance	0	0	0	1
Additional increases (decreases) on securities that had an allowance recorded in a previous period	0	0	0
Additions for which credit losses were not previously recorded				0
Reductions for securities sold during the period (realized)				(1)
Ending Balance	0	0	0	0
Commercial mortgage backed securities
Rollforward of Available-for-Sale securities allowance for credit losses
Beginning Balance	4	4	4	0
Additional increases (decreases) on securities that had an allowance recorded in a previous period	(1)	0	(1)
Additions for which credit losses were not previously recorded				4
Reductions for securities sold during the period (realized)				0
Ending Balance	3	4	3	4
State and municipal obligations
Rollforward of Available-for-Sale securities allowance for credit losses
Beginning Balance	1	1	1	1
Additional increases (decreases) on securities that had an allowance recorded in a previous period	0	0	0
Additions for which credit losses were not previously recorded				0
Reductions for securities sold during the period (realized)				0
Ending Balance	$ 1	$ 1	$ 1	$ 1

Amount of expense 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), for which no credit loss was previously recorded.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (b)
-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

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

+ References

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

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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

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