Covered Loans Receivable (Troubled Debt Restructured Loans) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014 contract		Dec. 31, 2013 contract
Covered Loans
Financing Receivable, Modifications [Line Items]
Performing TDRs, Covered TDRs	$ 10,289,000		$ 4,211,000
Nonaccrual TDRs, Covered TDRs	2,246,000		7,000
Performing TDRs, Allowance for loan losses on covered TDRs	1,000		660,000
Nonaccrual TDRs, Allowance for loan losses on covered TDRs	2,000		0
Covered Loans | Troubled Debt Restructured Loans
Financing Receivable, Modifications [Line Items]
Unfunded commitments related to credits classified as covered TDRs	0		0
Number of Contracts	12	[1]	3	[1]
Outstanding Principal Balance	12,516,000	[1],[2]	3,792,000	[1],[2]
Number of loans modified that subsequently defaulted	0		0
Covered Loans | Troubled Debt Restructured Loans | Extended Maturity [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	1	[1]
Related specific valuation allowance for TDRs	0
Covered Loans | Troubled Debt Restructured Loans | One-to-four Family Residential
Financing Receivable, Modifications [Line Items]
Number of Contracts	0	[1]	0	[1]
Outstanding Principal Balance	0	[1],[2]	0	[1],[2]
Covered Loans | Troubled Debt Restructured Loans | Extended Maturity [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts			2	[1]
Outstanding Principal Balance			13,000
Related specific valuation allowance for TDRs	1,000
Covered Loans | Troubled Debt Restructured Loans | Commercial Business
Financing Receivable, Modifications [Line Items]
Number of Contracts	11		3	[1]
Outstanding Principal Balance	12,088,000		3,792,000	[1],[2]
Covered Loans | Troubled Debt Restructured Loans | Commercial Business | Commercial and Industrial
Financing Receivable, Modifications [Line Items]
Number of Contracts	7	[1]	3	[1]
Outstanding Principal Balance	3,394,000	[1],[2]	3,792,000	[1],[2]
Covered Loans | Troubled Debt Restructured Loans | Commercial Business | Owner-occupied Commercial Real Estate
Financing Receivable, Modifications [Line Items]
Number of Contracts	2	[1]	0	[1]
Outstanding Principal Balance	1,133,000	[1],[2]	0	[1],[2]
Covered Loans | Troubled Debt Restructured Loans | Commercial Business | Non-owner Occupied Commercial Real Estate
Financing Receivable, Modifications [Line Items]
Number of Contracts	2	[1]	0	[1]
Outstanding Principal Balance	7,561,000	[1],[2]	0	[1],[2]
Covered Loans | Troubled Debt Restructured Loans | Real Estate Construction and Land Development
Financing Receivable, Modifications [Line Items]
Number of Contracts	1	[1]	0	[1]
Outstanding Principal Balance	428,000	[1],[2]	0	[1],[2]
Covered Loans | Troubled Debt Restructured Loans | Real Estate Construction and Land Development | One-to-four Family Residential
Financing Receivable, Modifications [Line Items]
Number of Contracts	0	[1]	0	[1]
Outstanding Principal Balance	0	[1],[2]	0	[1],[2]
Covered Loans | Troubled Debt Restructured Loans | Real Estate Construction and Land Development | Five or More Family Residential and Commercial Properties
Financing Receivable, Modifications [Line Items]
Number of Contracts	1	[1]	0	[1]
Outstanding Principal Balance	428,000	[1],[2]	0	[1],[2]
Covered Loans | Troubled Debt Restructured Loans | Consumer
Financing Receivable, Modifications [Line Items]
Number of Contracts	0	[1]	0	[1]
Outstanding Principal Balance	0	[1],[2]	0	[1],[2]
Purchased Impaired Covered Loans [Member] | Troubled Debt Restructured Loans | Washington Banking
Financing Receivable, Modifications [Line Items]
Number of Contracts	11	[1]
Outstanding Principal Balance	10,300,000
Related specific valuation allowance for TDRs	0
Purchased Impaired Covered Loans [Member] | Troubled Debt Restructured Loans | Payment Deferral
Financing Receivable, Modifications [Line Items]
Number of Contracts	4	[1]
Outstanding Principal Balance	7,700,000
Purchased Impaired Covered Loans [Member] | Troubled Debt Restructured Loans | Extended Maturity [Member]
Financing Receivable, Modifications [Line Items]
Outstanding Principal Balance	$ 2,200,000

[1] Number of contracts and outstanding principal balance represent loans which have balances as of year end as certain loans may have been paid-down or charged-off during the years ended December 31, 2014 and 2013.

[2] Includes subsequent payments after modifications and reflects the balance as of period end. As the Bank did not forgive any principal or interest balance as part of the loan modification, the Bank’s recorded investment in each loan at the date of modification (pre-modification) did not change as a result of the modification (post-modification).