Related Party Transactions - Additional Information (Details) (USD $)	3 Months Ended					3 Months Ended							3 Months Ended		3 Months Ended																				3 Months Ended		3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Mar. 31, 2014 HSBC Mexico [Member]	Dec. 31, 2013 HSBC Mexico [Member]	Mar. 31, 2014 HNAH [Member]	Dec. 31, 2013 HNAH [Member]	Mar. 31, 2014 HSBC Investment Bahamas [Member]	Dec. 31, 2013 HSBC Investment Bahamas [Member]	Mar. 31, 2014 HSBC [Member]	Dec. 31, 2013 HSBC [Member]	Mar. 31, 2014 HNAI [Member]	Mar. 31, 2014 HSBC Finance Corporation [Member]	Dec. 31, 2013 HSBC Finance Corporation [Member]	Mar. 31, 2014 HSBC Finance Corporation [Member] Extended Uncommitted Revolving Credit Facility	Mar. 31, 2014 HSBC Finance Corporation [Member] Extended Uncommitted Revolving Credit Facility Maturity Date, September 2017 [Member]	Mar. 31, 2014 HSBC Finance Corporation [Member] Extended Uncommitted Revolving Credit Facility Maturity Date, January 2018 [Member]	Mar. 31, 2014 HSBC Finance Corporation [Member] Extended Uncommitted Revolving Credit Facility Maturity Date, September 2018 [Member]	Mar. 31, 2014 HSBC Finance Corporation [Member] Extended committed revolving credit facility [Member]	Dec. 31, 2013 HSBC Finance Corporation [Member] Extended committed revolving credit facility [Member]	Mar. 31, 2014 HSBC Finance Corporation [Member] Residential Mortgage [Member]	Dec. 31, 2013 HSBC Finance Corporation [Member] Residential Mortgage [Member]	Mar. 31, 2014 HMUS [Member]	Dec. 31, 2013 HMUS [Member]	Mar. 31, 2014 HSBC Bank Brasil [Member]	Dec. 31, 2013 HSBC Bank Brasil [Member]	Mar. 31, 2014 Other Affiliates [Member]	Dec. 31, 2013 Other Affiliates [Member]	Mar. 31, 2014 Other Affiliates [Member] Extended committed revolving credit facility [Member]	Dec. 31, 2013 Other Affiliates [Member] Extended committed revolving credit facility [Member]	Mar. 31, 2014 Regency [Member]	Mar. 31, 2014 Hsbc Finance And Other Hsbc Affiliates [Member]	Dec. 31, 2013 Hsbc Finance And Other Hsbc Affiliates [Member]	Mar. 31, 2014 Five Year Floating Rate Note Maturing August 2014 [Member] HNAH [Member]	Mar. 31, 2014 Five Year Floating Rate Note Maturing August 2014 [Member] HNAH [Member] Senior Notes [Member]	Mar. 31, 2014 Loan Maturing in Three Equal Installments on April 2015, 2016, 2017 [Member] HNAH [Member]	Mar. 31, 2014 Loan Maturing in Three Equal Installments on April 2015, 2016, 2017 [Member] HNAH [Member] Senior Notes [Member] installment	Apr. 30, 2014 Subsequent Event [Member] HSBC Investment Bahamas [Member]
Related Party Transaction [Line Items]
Extended loans and lines of credit				$ 800,000,000	$ 500,000,000								$ 5,000,000,000.0										$ 6,700,000,000	$ 3,800,000,000	$ 1,500,000,000.0
Long-term debt	22,953,000,000		22,847,000,000			4,000,000,000
Senior notes																																		1,000,000,000		3,000,000,000
Debt term													364 days																						5 years
Number of equal installments																																					3
Notes mature installments period one																																				1,000,000,000
Senior note interest rate period						90 days
Loan and lease receivable unused line of credit facility								900,000,000		500,000,000		150,000,000																										1,000,000,000
Extended unsecured uncommitted credit facility to certain subsidiary maturity															15 years
Due from Related Parties																							931,000,000	199,000,000
Amount outstanding under the loan agreement						0	0
Loan And Lease Receivable Revolving Line Of Credit Outstanding								0	0	0	0				0				0										0	0
Due from Affiliates	5,277,000,000		5,328,000,000										3,015,000,000	3,015,000,000									931,000,000	199,000,000	1,000,000,000	1,000,000,000	331,000,000	1,114,000,000
Maturing amount of credit agreement																512,000,000	1,500,000,000	1,000,000,000
Maximum borrowing capacity																			1,000,000,000										2,300,000,000
Related Party Transaction, Liquidity Facility, Notional Amount																															2,300,000,000
Derivative, notional amount	5,452,406,000,000		5,457,095,000,000																													1,134,400,000,000	1,210,600,000,000
Fair value of derivative receivables																																319,000,000	845,000,000
Residential mortgage loans servicing																					944,000,000	983,000,000
Rent from related party	$ 14,000,000	$ 12,000,000