Loans (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums	$ 5,400,000	$ 6,600,000
Loans and Leases Receivable, Gross, Carrying Amount, Covered		547,943,000
Time period for non-payment of loans that are placed on non-accrual status	90 days
Days past due for nonaccrual status credit card loans	120 days
Covered impaired loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	451,200,000	756,100,000
Acquired Loans | Impaired loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance, including contractual principal, interest, fees and penalties, of all purchased loans	$ 590,900,000	$ 817,600,000