Allowance for Noncovered Loan and Lease Losses and Unfunded Commitments and Letters of Credit (Narrative) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013 Maximum [Member]	Apr. 02, 2013 West Coast Bancorp [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of unallocated loan amount	5.00%
discount on acquired loans		$ 88.8