Loans, Allowance for Loan and Lease Losses, and Reserve for Off-Balance Sheet Credit Commitments (Details 2) (Credit Risk)	6 Months Ended
	Jun. 30, 2013
Concentrations of credit risk
Number of states with largest concentration by loan type	5
Total loans outstanding | Noncovered loans | California
Concentrations of credit risk
Percent of total loans outstanding (as a percent)	78.00%
Total loans outstanding | Noncovered loans | New York
Concentrations of credit risk
Percent of total loans outstanding (as a percent)	7.00%
Total loans outstanding | Noncovered loans | Nevada
Concentrations of credit risk
Percent of total loans outstanding (as a percent)	2.00%
Total loans outstanding | Noncovered loans | Other states
Concentrations of credit risk
Percent of total loans outstanding (as a percent)	13.00%
Total loans outstanding | Covered loans | California
Concentrations of credit risk
Percent of total loans outstanding (as a percent)	36.00%
Total loans outstanding | Covered loans | New York
Concentrations of credit risk
Percent of total loans outstanding (as a percent)	5.00%
Total loans outstanding | Covered loans | Nevada
Concentrations of credit risk
Percent of total loans outstanding (as a percent)	7.00%
Total loans outstanding | Covered loans | Texas
Concentrations of credit risk
Percent of total loans outstanding (as a percent)	11.00%
Total loans outstanding | Covered loans | Arizona
Concentrations of credit risk
Percent of total loans outstanding (as a percent)	5.00%
Total loans outstanding | Covered loans | Other states
Concentrations of credit risk
Percent of total loans outstanding (as a percent)	36.00%