Related Party Transactions - Summary of Related Party Transactions (Details) - USD ($)		Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Assets:
Cash and due from banks		$ 1,235,000,000		$ 968,000,000		$ 891,000,000	$ 961,000,000
Interest bearing deposits with banks		20,238,000,000		7,478,000,000
Securities purchased under agreements to resell		30,023,000,000		19,847,000,000
Trading assets		16,850,000,000		17,085,000,000
Loans		73,875,000,000		82,917,000,000		77,741,000,000
Other assets		6,721,000,000		6,890,000,000
Total assets		201,301,000,000	[1]	188,278,000,000	[1]	185,539,000,000
Liabilities:
Deposits		129,248,000,000		118,579,000,000		116,118,000,000
Trading liabilities		4,908,000,000		7,455,000,000
Short-term borrowings		5,101,000,000		4,995,000,000		12,795,000,000
Long-term debt		37,739,000,000		33,509,000,000
Other		3,950,000,000		3,215,000,000
Total liabilities	[1]	180,946,000,000		167,753,000,000
Hnah [Member]
Related Party Transaction [Line Items]
Maximum borrowing capacity		150,000,000
Long-term Line of Credit		0
Liabilities:
Long-term debt		4,900,000,000		1,900,000,000
Hnai [Member]
Related Party Transaction [Line Items]
Maximum borrowing capacity				150,000,000
Long-term Line of Credit				0
Affiliated Entity [Member]
Related Party Transaction [Line Items]
Loans and leases receivable from related parties		3,274,000,000		4,815,000,000
Assets:
Cash and due from banks		364,000,000		169,000,000
Interest bearing deposits with banks		980,000,000		244,000,000
Securities purchased under agreements to resell	[2]	949,000,000		4,000,000,000
Trading assets		74,000,000		212,000,000
Loans		3,274,000,000		4,815,000,000		$ 4,821,000,000
Other assets	[3]	291,000,000		458,000,000
Total assets		5,932,000,000		9,898,000,000
Liabilities:
Deposits		23,999,000,000		13,486,000,000
Trading liabilities		510,000,000		1,954,000,000
Short-term borrowings		2,148,000,000		2,004,000,000
Long-term debt		4,834,000,000		1,827,000,000
Other	[3]	247,000,000		346,000,000
Total liabilities		$ 31,738,000,000		$ 19,617,000,000

[1] The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") at December 31, 2016 and December 31, 2015 which are consolidated on our balance sheet. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 24, "Variable Interest Entities," for additional information. Assets: Other assets $231 million and $320 million. Total assets $231 million and $320 million respectively. Liabilities: Long-term debt $79 million and $92 million, Interest, taxes and other liabilities $60 million and $68 million. Total liabilities $139 million and $160 million, respectively.

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

[3] Other assets and other liabilities primarily consist of derivative balances associated with hedging activities and other miscellaneous account receivables and payables.