Finance Receivables and Loans, Net - Schedule of Allowance for Credit Losses on Financing Receivables (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance, beginning balance	$ 3,490	$ 3,714	$ 3,714
Charge-offs	(672)	(745)	(2,683)
Recoveries	255	238
Net charge-offs	(417)	(507)
Provision for credit losses	467	191
Other	0	0
Allowance, ending balance	3,540	3,398	3,490
Consumer
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Charge-offs	(671)		(2,681)
Consumer \| Consumer automotive
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance, beginning balance	3,208	3,170	3,170
Charge-offs	(671)	(676)	(2,610)
Recoveries	247	231
Net charge-offs	(424)	(445)
Provision for credit losses	467	418
Other	(1)	1
Allowance, ending balance	3,250	3,144	3,208
Consumer \| Consumer mortgage
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance, beginning balance	12	19	19
Charge-offs	0	0	(3)
Recoveries	8	1
Net charge-offs	8	1
Provision for credit losses	(9)	0
Other	0	(2)
Allowance, ending balance	11	18	12
Consumer \| Other
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance, beginning balance		319	319
Charge-offs		(68)	(68)
Recoveries		5
Net charge-offs		(63)
Provision for credit losses		(257)
Other		1
Allowance, ending balance		0
Commercial
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Allowance, beginning balance	270	206	206
Charge-offs	(1)	(1)	(2)
Recoveries	0	1
Net charge-offs	(1)	0
Provision for credit losses	9	30
Other	1	0
Allowance, ending balance	279	$ 236	270
Commercial \| Consumer automotive
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Charge-offs			$ (2)
Commercial \| Other
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Charge-offs	$ (1)

Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Other

No definition available.

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- Definition

Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479344/326-20-45-1

+ Details

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- Definition

Amount, excluding accrued interest, of increase in allowance for credit loss on financing receivable from recovery. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

+ Details

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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.

+ Details

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- Definition

Amount, excluding accrued interest, of decrease in allowance for credit loss on financing receivable from writeoff. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-6

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- Definition

Amount, excluding accrued interest, of decrease (increase) in allowance for credit loss on financing receivable from writeoff (recovery). Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

+ Details

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- Definition

Amount, excluding accrued interest, of credit loss expense (reversal of expense) on financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

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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