Business Combinations narrative (Details) (USD $)	7 Months Ended		12 Months Ended			0 Months Ended		0 Months Ended		0 Months Ended		0 Months Ended		0 Months Ended
	Dec. 31, 2011	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Aug. 05, 2011 Bank of Whitman [Member] location	Dec. 31, 2011 Bank of Whitman [Member] location	May 27, 2011 First Heritage Bank [Member] location	Dec. 31, 2011 First Heritage Bank [Member]	May 20, 2011 Summit Bank [Member]	Dec. 31, 2011 Summit Bank [Member]	Jan. 29, 2010 American Marine Bank [Member]	May 27, 2011 American Marine Bank [Member] location	Jan. 22, 2010 Columbia River Bank [Member] location	May 27, 2011 Scenario, Previously Reported [Member] First Heritage Bank [Member]	May 20, 2011 Scenario, Previously Reported [Member] Summit Bank [Member]
Business Acquisition [Line Items]
Business Acquisition, Purchase Price Allocation, Assets Acquired						$ 437,549,000		$ 164,984,000		$ 131,129,000		$ 307,822,000		$ 912,878,000
Business Acquisition, Purchase Price Allocation, Loans Covered By Loss Sharing								8,225,000		2,162,000		8,680,000		8,714,000	8,300,000	2,700,000
Business Acquisition, Effective Date of Acquisition						Aug. 05, 2011		May 27, 2011		May 20, 2011		Jan. 29, 2010		Jan. 22, 2010
Business Combination, Acquired Receivables, Fair Value						200,041,000		81,488,000		69,783,000		176,278,000		480,306,000	81,900,000	71,400,000
Number Of Branch Locations To Be Acquired						9		5					11	21
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net						1,830,000						9,818,000
Gain on bank acquisitions, net of tax			0	1,830,000	9,818,000	1,800,000
Business Acquisition, Purchase Price Allocation, Amortizable Intangible Assets						3,943,000		1,337,000		509,000		4,313,000		13,442,000
Number Of Branch Locations Excluded From Operating Results							11
Percentage of loss shared by FDIC									80.00%		80.00%
FDIC Percentage Of Loss Recoveries									80.00%		80.00%
Business Acquisition, Purchase Price Allocation, FDIC Indemnification Asset								38,531,000		30,203,000		70,442,000		189,822,000	38,100,000	27,200,000
Business Acquisition, Purchase Price Allocation, Other Assets						2,447,000		3,657,000		1,813,000		498,000		615,000	1,700,000	786,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Acquired Loans	(369,000)	(1,700,000)
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Loans Covered By Loss Sharing	(61,000)	(509,000)
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, FDIC Indemnification Asset	427,000	3,000,000
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Other Assets	1,900,000	1,000,000
Business Acquisition, Purchase Price Allocation, Goodwill Amount								4,023,000		1,892,000				14,120,000
Business Acquisition, Purchase Price Allocation, Current Assets, Marketable Securities						16,298,000		5,303,000		871,000		28,592,000		100,650,000
Business Acquisition, Purchase Price Allocation, Current Assets, Cash and Cash Equivalents												14,500,000		98,100,000
Business Combinations,Purchase Price Allocation, Other noncurrent assets not previously stated in narrative												18,000,000		44,000,000
business combinations, purchase price allocation, liabilities assumed excluding deferred tax liability												292,600,000
Business Acquisition, Purchase Price Allocation, Liabilities Assumed						435,719,000		164,984,000		131,129,000		298,004,000		912,878,000
Business Acquisition, Purchase Price Allocation, Liabilities, Deposits						401,127,000		159,525,000		123,279,000		253,965,000		893,356,000
Business Acquisition, Purchase Price Allocation, Federal Home Loan Bank Advances						32,949,000		5,003,000		7,772,000		37,682,000		18,428,000
business combinations, purchase price allocation, other liabilities not previously mentioned in narrative												$ 974,000		$ 1,100,000