Loans - Components of Loans (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 77,741		$ 67,695		$ 63,258
Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total commercial	58,087		48,494
Total loans	58,087		48,494
Commercial Loans [Member] | Construction and Other Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total commercial	10,300		9,034
Total loans	10,300		9,034		8,457
Commercial Loans [Member] | Business and Corporate Banking [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total commercial	17,819		14,446
Total loans	17,819		14,446		12,608
Commercial Loans [Member] | Global Banking [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total commercial	26,387	[1]	21,625	[1]
Total loans	26,387		21,625		20,009
Commercial Loans [Member] | Other Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total commercial	3,581		3,389
Total loans	3,581		3,389		3,076
Consumer Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total consumer	19,654		19,201
Total loans	19,654		19,201
Consumer Loans [Member] | Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total consumer	16,661		15,826
Total loans	16,661		15,826		15,371
Consumer Loans [Member] | Home Equity Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total consumer	1,784		2,011
Total loans	1,784	[2]	2,011		2,324
Consumer Loans [Member] | Credit Cards [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total consumer	720		854
Total loans	720	[3]	854		815
Consumer Loans [Member] | Other consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total consumer	489		510
Total loans	$ 489		$ 510		$ 598

[1] Represents large multinational firms including globally focused U.S. corporate and financial institutions and U.S. dollar lending to multinational banking customers managed by HSBC on a global basis. Also includes loans to HSBC affiliates which totaled $4,821 million and $5,328 million at December 31, 2014 and 2013, respectively. See Note 22, "Related Party Transactions," for additional information regarding loans to HSBC affiliates.

[2] Home equity mortgage maturities reflect estimates based on historical payment patterns.

[3] As credit card receivables do not have stated maturities, the table reflects estimates based on historical payment patterns.