Related Party Transactions - Summary of Related Party Transactions (Details) - USD ($) $ in Millions		Jun. 30, 2015		Dec. 31, 2014		Jun. 30, 2014		Dec. 31, 2013
Assets:
Cash and due from banks		$ 1,077		$ 891		$ 2,325		$ 961
Interest bearing deposits with banks		20,059		30,807
Securities purchased under agreements to resell		16,112		1,413
Trading assets		17,771		21,092
Loans		83,617		77,741		72,198
Other assets		8,812		7,989
Total assets		196,618	[1]	185,539	[1]	182,218
Liabilities:
Deposits		122,547	[1],[2]	116,118	[1]	$ 115,521	[2]
Trading liabilities	[1]	6,448		8,164
Short-term borrowings	[1]	12,728		12,795
Long-term debt	[1]	30,567		27,524
Other	[1]	3,675		3,971
Total liabilities	[1]	175,965		168,572
HSBC Mexico [Member]
Assets:
Interest bearing deposits with banks		650		800
Affiliated Entity [Member]
Assets:
Cash and due from banks		265		140
Interest bearing deposits with banks	[3]	906		928
Securities purchased under agreements to resell	[4]	4,000		0
Trading assets	[5]	16,916		20,194
Loans		4,607		4,821
Other assets	[6]	855		983
Total assets		27,549		27,066
Liabilities:
Deposits		13,286		16,596
Trading liabilities	[5]	18,019		21,130
Short-term borrowings		2,504		847
Long-term debt		1,828		3,981
Other	[6]	511		459
Total liabilities		$ 36,148		$ 43,013

[1] The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") as of June 30, 2015 and December 31, 2014 which are consolidated on our balance sheet. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 216, "Variable Interest Entities," for additional information. Assets: Other assets $355 million and $380 million. Total assets $355 million and $380 million respectively. Liabilities: Long-term debt $92 million and $92 million, Interest, taxes and other liabilities $84 million and $75 million. Total liabilities $176 million and $167 million, respectively.

[2] During the second quarter of 2015, we concluded that brokered deposits would be better presented as debt under the Group Reporting Basis. As a result, we reclassified $1.8 billion of brokered deposits in the GB&M segment to debt at June 30, 2014 to conform with current year presentation.

[3] Includes interest bearing deposits with HSBC Mexico S.A. of $650 million and $800 million at June 30, 2015 and December 31, 2014, respectively.

[4] Reflects overnight purchases of U.S. Treasury securities which HSBC Securities (USA) Inc. ("HSI") has agreed to repurchase.

[5] Trading assets and trading liabilities do not reflect the impact of netting which allows the offsetting of amounts relating to certain contracts if certain conditions are met. Trading assets and liabilities primarily consist of derivatives contracts.

[6] Other assets and other liabilities primarily consist of derivative contracts.