Commitments and contingencies disclosure.

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- Definition

Remaining unfunded amount of commercial lending committed to dealers, in the form of construction loans.

+ References

No definition available.

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- Definition

Unused portion of commercial lending committed to dealers, in the form of lines of credit.

+ References

No definition available.

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- Definition

Amount of damages awarded to the plaintiff in the legal matter.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483076/450-20-50-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition

Amount of operating lease expense. Excludes sublease income.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
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-Subparagraph (b)
-Publisher FASB
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- Definition

Weighted average discount rate for operating lease calculated at point in time.

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Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 53
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479589/842-20-55-53

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Weighted average remaining lease term for operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 53
-Publisher FASB
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Commitments and Contingencies - Narrative (Detail) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Jan. 31, 2025	Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2023
Commitments And Contingencies Disclosure [Line Items]
Operating lease, expense		$ 9	$ 10	$ 10
Weighted average remaining lease term		6 years 8 months 12 days
Weighted average discount rate (percent)		3.00%
Consumer Financial Protection Bureau Consent Order \| Pending Litigation \| Consumer Redress
Commitments And Contingencies Disclosure [Line Items]
Loss contingency, damages awarded, value	$ 10
Consumer Financial Protection Bureau Consent Order \| Pending Litigation \| Civil Money Penalty
Commitments And Contingencies Disclosure [Line Items]
Loss contingency, damages awarded, value	$ 3
Revolving lines of credit
Commitments And Contingencies Disclosure [Line Items]
Unused balance of commercial revolving lines of credit		$ 671
Construction of automobile dealerships
Commitments And Contingencies Disclosure [Line Items]
Remaining unfunded balance for construction loans		$ 3