Related Party Transactions (Details 3) (HSBC Bank USA [Member], USD $) In Billions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Receivable portfolio
Receivables serviced for HSBC Bank USA					$ 22.4
Receivables sold on daily basis	2.5	8.8	10.4	16.7
Private Label [Member]
Receivable portfolio
Receivables serviced for HSBC Bank USA					12.8
Receivables sold on daily basis	1.1	3.6	4.4	6.8
General Motors [Member]
Receivable portfolio
Receivables serviced for HSBC Bank USA					4.1
Receivables sold on daily basis	1.0	3.3	3.9	6.4
Union Privilege [Member]
Receivable portfolio
Receivables serviced for HSBC Bank USA					3.5
Receivables sold on daily basis	0.3	0.8	1.0	1.5
Other [Member]
Receivable portfolio
Receivables serviced for HSBC Bank USA					2.0
Receivables sold on daily basis	$ 0.1	$ 1.1	$ 1.1	$ 2.0