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Commitments and Contingent Liabilities (Details) - USD ($) $ in Thousands |  |  | 9 Months Ended |
--- | --- | --- | --- | ---
Aug. 11, 2017 | Aug. 24, 2016 | Sep. 30, 2017 | Dec. 31, 2016
Commitments to Extend Credit [Member] |  |  |  |
Other Commitments [Line Items] |  |  |  |
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability |  |  | $ 2,230,000 | $ 2,170,000
Standby Letters of Credit [Member] |  |  |  |
Other Commitments [Line Items] |  |  |  |
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability |  |  | 50,100 | 49,700
Commercial Letter of Credit and other off-balance sheet liabilities [Member] |  |  |  |
Other Commitments [Line Items] |  |  |  |
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Liability |  |  | 2,900 | $ 3,400
IDAHO |  |  |  |
Other Commitments [Line Items] |  |  |  |
Sale Leaseback Transaction, Date | August 11, 2017 |  |  |
Sale Leaseback Transaction, Monthly Rental Payments |  |  | 26 |
Sale Leaseback Transaction, Deferred Gain, Gross | $ 509 |  |  |
Sale Leaseback Transaction, Deferred Gain, Net |  |  | 501 |
WASHINGTON |  |  |  |
Other Commitments [Line Items] |  |  |  |
Sale Leaseback Transaction, Date |  | August 24, 2016 |  |
Sale Leaseback Transaction, Monthly Rental Payments |  |  | 12 |
Sale Leaseback Transaction, Deferred Gain, Gross |  | $ 742 |  |
Sale Leaseback Transaction, Deferred Gain, Net |  |  | $ 661 |

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- Definition The fair value of financial liabilities, which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13433-108611 + Details
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- Definition The date of the transaction involving the sale of the property to another party and the lease of the property back to the seller. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 40 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=77913982&loc=d3e50796-112755 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 40 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=77888430&loc=SL77919786-209982 + Details
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- Definition The portion of the gain that will be recorded as income or a reduction in rent expense in future periods less amounts recognized in the current period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 40 -Section 35 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=77907795&loc=d3e50609-112754 + Details
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- Definition The amount of the monthly rental payments due under the lease entered into in connection with the transactions involving the sale of property to another party and the lease of the property back to the seller. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 40 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=77913982&loc=d3e50796-112755 + Details
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