Troubled Debt Restructures and Nonperforming Receivables - Additional Information on Nonaccrual Receivables (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016
Receivables [Abstract]
Interest income that would have been recorded if the nonaccrual receivable had been current in accordance with contractual terms during the period	$ 15	$ 59
Interest income that was recorded on nonaccrual receivables during the period	$ 2	$ 18

Loans and Leases Receivable, Impaired, Interest Recorded and Interest Lost on Nonaccrual Loans

No definition available.

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