Business Combinations (Unaudited Pro Forma) (Details) (Washington Banking, USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Washington Banking
Business Acquisition [Line Items]
Net interest income	$ 144,470	$ 147,267
Net income	$ 35,758	$ 30,718
Basic earnings per common share (in usd per share)	$ 1.19	$ 1.04
Diluted earnings per common share (in usd per share)	$ 1.18	$ 1.04

Business Acquisition, Pro Forma Net Interest Income (Loss)

No definition available.

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- Definition

The pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(2)-(3)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

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The pro forma diluted net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

+ References

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The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

+ References

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