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Business Combinations (Details) - Intermountain Community Bancorp [Member] - USD ($) $ / shares in Units, $ in Thousands |  | 12 Months Ended
--- | --- | ---
Nov. 01, 2014 | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Business Acquisition [Line Items] |  |  |  |
Business Combination, Cost of Acquired Entity, Purchase Price, Total | $ 131,935 |  |  |
Business Combination, Acquisition Related Costs |  | $ 2,436 | $ 10,845 | $ 4,896
Business Acquisition, Effective Date of Acquisition | Nov. 01, 2014 |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents | $ 47,283 |  |  |
Business Acquisition, Purchase Price Allocation, Current Assets, Marketable Securities | 299,458 |  |  |
Business Acquisition, Purchase Price Allocation, FHLB Stock | 2,124 |  |  |
Business Combination, Acquired Receivables, Fair Value | 502,595 |  |  |
Business Acquisition, Purchase Price Allocation, Accrued Interest Receivable | 4,656 |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment | 20,696 |  |  |
Business Acquisition, Purchase Price Allocation, Other Real Estate Owned | 2,752 |  |  |
Business Combination, Purchase Price Allocation, Amortizable Intangible Assets | 10,900 |  |  |
Business Combination, Purchase Price Allocation, Other Assets | 35,128 |  |  |
Business Acquisition, Purchase Price Allocation, Liabilities, Deposits | (736,795) |  |  |
Business Acquisition, Purchase Price Allocation, Junior Subordinated Debentures | (22,904) |  |  |
Business combination, purchase price allocation, securities sold under agreements to repurchase | (59,043) |  |  |
Business Acquisition, Purchase Price Allocation, Other Noncurrent Liabilities | (13,725) |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net | 93,125 |  |  |
Business Combination, Purchase Price Allocation, Goodwill Amount | $ 38,810 |  |  |
Business Acquisition, Pro Forma Revenue |  |  |  | 397,152
Business Acquisition, Pro Forma Net Income (Loss) |  |  |  | $ 85,939
Business Acquisition, Pro Forma Earnings Per Share, Basic |  |  |  | $ 1.56
Business Acquisition, Pro Forma Earnings Per Share, Diluted |  |  |  | $ 1.55
Compensation and employee benefits [Member] |  |  |  |
Business Acquisition [Line Items] |  |  |  |
Business Combination, Acquisition Related Costs |  | 35 | 3,828 | $ 2,077
Occupancy [Member] |  |  |  |
Business Acquisition [Line Items] |  |  |  |
Business Combination, Acquisition Related Costs |  | 2,383 | 2,357 | 44
Advertising and promotion [Member] |  |  |  |
Business Acquisition [Line Items] |  |  |  |
Business Combination, Acquisition Related Costs |  | 0 | 448 | 464
Data processing and communications [Member] |  |  |  |
Business Acquisition [Line Items] |  |  |  |
Business Combination, Acquisition Related Costs |  | 18 | 2,005 | 0
Legal and professional fees [Member] |  |  |  |
Business Acquisition [Line Items] |  |  |  |
Business Combination, Acquisition Related Costs |  | 0 | 1,247 | 2,114
Other noninterest expenses [Member] |  |  |  |
Business Acquisition [Line Items] |  |  |  |
Business Combination, Acquisition Related Costs |  | $ 0 | $ 960 | $ 197

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- Definition Amount of goodwill arising from a business combination, which is the excess of the cost of the acquired entity over the amounts assigned to assets acquired and liabilities assumed. + References No definition available. + Details
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- Definition Date when the acquirer obtains control of the acquiree, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 25 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=73531572&loc=d3e845-128460 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Acquisition Date -URI http://asc.fasb.org/extlink&oid=6919109 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 25 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=73531572&loc=d3e848-128460 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=65885119&loc=d3e1392-128463 + Details
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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=65885119&loc=d3e1392-128463 + Details
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- Definition 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 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=65885119&loc=d3e1392-128463 + Details
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- Definition For receivables acquired in a business combination, excluding certain loans and debt securities acquired in a transfer (as defined), this element represents the fair value of the receivables acquired, by major class of receivable, such as loans, direct finance leases (as defined), and any other class of receivables. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=73530397&loc=d3e4845-128472 + Details
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- Definition This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 25 -Paragraph 23 -URI http://asc.fasb.org/extlink&oid=73531572&loc=d3e1043-128460 + Details
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- Definition Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6578-128477 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6613-128477 + Details
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- Definition Amount of currency on hand as well as demand deposits with banks or financial institutions, acquired at the acquisition date. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=73530397&loc=d3e4845-128472 + Details
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- Definition Amount of investments in debt and equity securities, including, but not limited to, held-to-maturity, trading and available-for-sale expected to be converted to cash, sold or exchanged within one year or the normal operating cycle, if longer, acquired at the acquisition date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=73530397&loc=d3e4845-128472 + Details
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- Definition Amount recognized as of the acquisition date for the identifiable assets acquired in excess of (less than) the aggregate liabilities assumed. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 55 -Paragraph 37 -URI http://asc.fasb.org/extlink&oid=73531372&loc=d3e2207-128464 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=73530397&loc=d3e4845-128472 + Details
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- Definition Amount of long-term debt due after one year or the normal operating cycle, if longer, assumed at the acquisition date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=73530397&loc=d3e4845-128472 + Details
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- Definition The amount of property, plant, and equipment recognized as of the acquisition date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=73530397&loc=d3e4845-128472 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 55 -Paragraph 37 -URI http://asc.fasb.org/extlink&oid=73531372&loc=d3e2207-128464 + Details
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