Allowance for Noncovered Loan and Lease Losses and Unfunded Commitments and Letters of Credit (Narrative) (Details) (USD $)	3 Months Ended	9 Months Ended			9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012	Apr. 02, 2013	Sep. 30, 2013 Maximum [Member]	Sep. 30, 2013 West Coast Bancorp [Member]	Sep. 30, 2013 Noncovered Loans [Member]	Sep. 30, 2012 Noncovered Loans [Member]	Sep. 30, 2013 Noncovered Loans [Member]	Sep. 30, 2012 Noncovered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of unallocated loan amount					5.00%
Provision for loan and lease losses		$ 3,581,000	$ 34,506,000				$ 4,260,000	$ 2,875,000	$ 5,260,000	$ 11,125,000
discount on acquired loans				88,800,000
Discount Accretion on Other Acquired Loans						19,700,000
Change in Accounting Estimate, Financial Effect	2,800,000
Change in estimate, impact to earnings per share	$ (0.05)	$ (0.06)