Financing Receivable, Modified, Commitment To Lend

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Financing Receivable, Repayment Through Operation Or Sale Of Collateral, Collateral

+ References

No definition available.

+ Details

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Namespace Prefix:	hsbcusa_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-3

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3)(c)(3))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
-Section 40
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481628/310-20-40-7

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481990/310-10-45-2

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amortized cost excluding accrued interest, before allowance for credit loss, of 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 5
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-5

Reference 2: 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

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amortized cost excluding accrued interest, of financing receivable modified during period for debtor experiencing financial difficulty.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-42

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amortized cost excluding accrued interest, of financing receivable with payment default in current period and modified within previous 12 months preceding payment default for debtor experiencing financial difficulty.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 44
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-44

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of interest income on financing receivable on nonaccrual status.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-16

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

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- Details

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- Details

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- Details

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- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerLoanMember
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- Details

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Loans - Narrative (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
Loans - Narrative (Detail) - USD ($) $ in Millions	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025	Dec. 31, 2025
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net	$ 62,103		$ 62,103		$ 59,894
Interest income that was recorded on nonaccrual loans and included in interest income during the period	0	$ 0	0	$ 0
90+ Days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net	197		197		229
Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net	41,671		41,671		39,344
Collateral-dependent loans	605		605		513
Loans modified	121	129	249	139
Additional commitments for loans modified	100		100		116
Commercial loans \| 90+ Days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net	69		69		121
Loans modified, subsequently default			0	0
Commercial loans \| Business and corporate banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net	30,926		30,926		28,305
Loans modified	37	129	148	139
Commercial loans \| Business and corporate banking \| Reclassification
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net					3,200
Commercial loans \| Business and corporate banking \| 90+ Days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net	69		69		15
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net	20,432		20,432		20,550
Loans modified	0	$ 0	0	$ 0
Consumer loans \| 90+ Days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net	128		128		108
Consumer loans \| Residential mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net	19,584		19,584		19,789
Collateral-dependent loans	274		274		256
Consumer loans \| Residential mortgages \| 90+ Days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net	$ 119		$ 119		$ 100