Litigation and Regulatory Matters - Additional Information (Details) (USD $)	1 Months Ended		3 Months Ended	6 Months Ended	1 Months Ended			1 Months Ended	0 Months Ended	12 Months Ended			0 Months Ended	12 Months Ended	1 Months Ended	12 Months Ended	36 Months Ended			1 Months Ended		1 Months Ended		1 Months Ended	6 Months Ended
	Feb. 29, 2012 entity	Nov. 30, 2011 class_action	Jun. 30, 2013	Jun. 30, 2013 Officers	Dec. 31, 2012 Bayerische Landesbank [Member]	Jul. 22, 2013 Levin, Jura and Hanes [Member] class_action	Oct. 31, 2012 DeKalb County [Member] county	Dec. 31, 2010 Madoff Litigation [Member]	Feb. 28, 2013 Foreclosure Practices [Member] mortgage_servicer	Dec. 31, 2012 Foreclosure Practices [Member]	Feb. 29, 2012 Foreclosure Practices [Member] HSBC Bank USA [Member] Services state	Dec. 31, 2011 Foreclosure Practices [Member] HSBC Bank USA [Member]	Feb. 28, 2013 Foreclosure Practices [Member] Hsbc North America [Member]	Dec. 31, 2012 Foreclosure Practices [Member] Hsbc North America [Member]	Dec. 31, 2012 AML/BSA Related Litigation [Member] HSBC Bank USA [Member]	Dec. 31, 2012 AML/BSA Related Litigation [Member] Hsbc North America [Member]	Dec. 31, 2007 Mortgage Securitization Activity Related Litigation [Member] HSBC Securities [Member]	Jun. 30, 2013 Mortgage Securitization Activity Related Litigation [Member] HSBC Securities [Member]	Dec. 31, 2012 Mortgage Securitization Activity Related Litigation [Member] HSBC Securities [Member]	Jan. 31, 2012 Residential Mortgage Backed Securities Related Litigation [Member]	Jun. 30, 2013 Residential Mortgage Backed Securities Related Litigation [Member] class_action Institution	Feb. 29, 2012 Residential Mortgage Backed Securities Related Litigation [Member] HSH Nordbank AG [Member]	Jun. 30, 2013 Residential Mortgage Backed Securities Related Litigation [Member] HSBC Securities [Member]	Jun. 30, 2013 DBNTC Litication [Member]	Jun. 30, 2013 DBNTC Litication [Member]
Loss Contingencies [Line Items]
Estimate of loss			$ 1,800,000,000	$ 1,800,000,000
Number of actions						3															1
Number of counties acting as plaintiff							3
Number of counties in area							5
Percentage threshold				20.00%
Number of class actions		3
Damages and additional recoveries sought								9,000,000,000																508,000,000
Number of mortgage servicers									12
Cash payments mortgage servicers would pay in excess									9,300,000,000
Cash payment into a fund that will be used to make payments to borrowers													96,000,000
Recorded expenses of loss contingency										19,000,000				104,000,000
Number of states under different departments											49
Number of U.S. mortgage servicers with which settlement is announced											5
Accrual portion of HSBC North												38,000,000
Recoveries			6,000,000
Payments to authorities															1,381,000,000	1,921,000,000
Loans sold to HIS																	24,000,000,000
Outstanding principal balance on loan																		6,900,000,000	7,400,000,000
Number of former and current officers and directors				5
Unpaid principal balance of securities																							1,600,000,000
Number of financial institutions																					17
Alleged purchased by plaintiff					$ 75,000,000															$ 122,400,000		$ 41,300,000
Number of entities	2
Compliance period, one																									5 years
Compliance period, two																									2 years