Loans - Components of Loans (Details) - USD ($) $ in Millions		Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 83,617	$ 77,741	$ 72,198
Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total commercial		63,596	58,087
Total loans		63,596	58,087
Commercial Loans [Member] | Construction and Other Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total commercial		11,520	10,300
Total loans		11,520	10,300	9,682
Commercial Loans [Member] | Business and Corporate Banking [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total commercial		19,712	17,819
Total loans		19,712	17,819	15,956
Commercial Loans [Member] | Global Banking [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total commercial	[1]	28,942	26,387
Total loans		28,942	26,387	24,268
Commercial Loans [Member] | Other Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total commercial		3,422	3,581
Total loans		3,422	3,581	3,127
Consumer Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total consumer		20,021	19,654
Total loans		20,021	19,654
Consumer Loans [Member] | Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total consumer		17,233	16,661
Total loans		17,233	16,661	16,097
Consumer Loans [Member] | Home Equity Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total consumer		1,686	1,784
Total loans		1,686	1,784	1,914
Consumer Loans [Member] | Credit Cards [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total consumer		692	720
Total loans		692	720	681
Consumer Loans [Member] | Other consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total consumer		410	489
Total loans		$ 410	$ 489	$ 473

[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 $4,607 million and $4,821 million at June 30, 2015 and December 31, 2014, respectively. See Note 13, "Related Party Transactions," for additional information regarding loans to HSBC affiliates.