Derivative Financial Instruments - Gain or Loss Recorded on Our Cash Flow Hedging Relationships (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Derivatives, Fair Value [Line Items]
Gain (Loss) Recognized in AOCI on Derivative (Effective Portion)	$ 59	$ 191	$ 184
Gain (Loss) Reclassed From AOCI into Income (Effective Portion)	(11)	(214)	(27)
Interest rate swaps [Member]
Derivatives, Fair Value [Line Items]
Gain (Loss) Recognized in AOCI on Derivative (Effective Portion), Interest Rate Swaps	45	118	95
Currency swaps [Member]
Derivatives, Fair Value [Line Items]
Gain (Loss) Recognized in AOCI on Derivative (Effective Portion), Currency Swaps	14	73	89
Interest Expense [Member] \| Interest rate swaps [Member]
Derivatives, Fair Value [Line Items]
Gain (Loss) Reclassed from AOCI into Income (Effective Portion), Interest Rate Swaps	1	(2)	(7)
Interest Expense [Member] \| Currency swaps [Member]
Derivatives, Fair Value [Line Items]
Gain (Loss) Reclassed from AOCI into Income (Effective Portion), Currency swaps	(12)	(13)	(20)
Derivative related income (loss) [Member]
Derivatives, Fair Value [Line Items]
Gain (Loss) Reclassed From AOCI into Income (Effective Portion, Derivative loss recognized on termination of hedges))	0	(199)	0
Gain (Loss) Recognized In Income on Derivative (Ineffective Portion)	14	29	23
Derivative related income (loss) [Member] \| Interest rate swaps [Member]
Derivatives, Fair Value [Line Items]
Gain (Loss) Recognized in Income on Derivative (Ineffective Portion), Interest Rate Swaps	0	2	1
Derivative related income (loss) [Member] \| Currency swaps [Member]
Derivatives, Fair Value [Line Items]
Gain (Loss) Recognized in Income on Derivative (Ineffective Portion, Currency swaps)	$ 14	$ 27	$ 22

Unrealized Gain Loss On Cash Flow Hedges PreTax Accumulated Other Comprehensive Income Loss

No definition available.

Name:	hsbcfc_UnrealizedGainLossOnCashFlowHedgesPreTaxAccumulatedOtherComprehensiveIncomeLoss
Namespace Prefix:	hsbcfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624171-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4D

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624177-113959

+ Details

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

- Details

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

- Definition

The amount of net gains or losses on foreign currency cash flow hedges reclassified during the period to earnings from accumulated other comprehensive income upon the hedged transaction affecting earnings.

+ References

+ Details

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

- Definition

The net gain (loss) recognized in earnings during the reporting period representing the amount of the cash flow hedges' ineffectiveness.

+ References

+ Details

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

- Definition

The net gain (loss) during the reporting period due to ineffectiveness in foreign currency cash flow hedges. Recognized in earnings.

+ References

+ Details

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

- Definition

The net gain (loss) during the reporting period due to ineffectiveness in interest rate cash flow hedges. Recognized in earnings.

+ References

+ Details

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

- Definition

The amount of net gains or losses on interest rate cash flow hedges reclassified during the period to earnings from accumulated other comprehensive income upon the hedged transaction affecting earnings.

+ References

+ Details

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

- Definition

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 55

-Paragraph 4K

-URI http://asc.fasb.org/extlink&oid=35736750&loc=SL4591552-111686

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 45

-Paragraph 19

-URI http://asc.fasb.org/extlink&oid=7656940&loc=SL4569616-111683

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 1A

-Subparagraph (a),(c)

-URI http://asc.fasb.org/extlink&oid=18733093&loc=SL4573702-111684

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 55

-Paragraph 4J

-URI http://asc.fasb.org/extlink&oid=35736750&loc=SL4591551-111686

+ Details

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

- Definition

Amount of unrealized gain (loss) related to the increase or decrease in fair value of interest rate derivatives designated as cash flow hedging instruments, which was recorded in accumulated other comprehensive income to the extent that the cash flow hedge was determined to be effective.

+ References

+ Details

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

- Definition

Amount of unrealized gain related to the increase in fair value of foreign currency exchange rate derivatives designated as cash flow hedging instruments. Recorded in accumulated other comprehensive income to the extent that the cash flow hedge is determined to be effective.

+ References

+ Details

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

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_CurrencySwapMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=hsbcfc_DerivativeRelatedIncomeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_InterestExpenseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: