Receivables - Nonaccrual Receivables (Parenthetical) (Detail) (Real estate secured [Member], USD $) In Billions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Real estate secured [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual real estate secured receivables lower of amortized cost	$ 1.5	$ 4.7

Nonaccrual real estate secured receivables carried at lower amortized cost or fair value.

No definition available.

Name:	hsbcfc_NonaccrualRealEstateSecuredReceivablesCarriedAtLowerAmortizedCostOrFairValue
Namespace Prefix:	hsbcfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant