Securities (Carrying Value of Securities Pledged as Collateral) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Carrying amount of securities pledged as collateral	$ 374,730	$ 420,243
To Washington and Oregon State To Secure Public Deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Carrying amount of securities pledged as collateral	281,006	225,345
To Federal Home Loan Bank To Secure Advances [Member]
Schedule of Available-for-sale Securities [Line Items]
Carrying amount of securities pledged as collateral	0	91,097
To Federal Reserve Bank To Secure Borrowings [Member]
Schedule of Available-for-sale Securities [Line Items]
Carrying amount of securities pledged as collateral	47,634	56,347
Other Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Carrying amount of securities pledged as collateral	$ 46,090	$ 47,454