Glacier Bancorp (GBCI) 10-K 22 Feb 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Feb. 05, 2018	Jun. 30, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	GLACIER BANCORP INC
Trading Symbol	GBCI
Entity Central Index Key	868,671
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Amendment Flag	false
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 2,837,602,927
Entity Common Stock, Shares Outstanding		79,785,733

Consolidated Statements of Fina

Consolidated Statements of Financial Condition - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets
Cash on hand and in banks	$ 139,948	$ 135,268
Interest bearing cash deposits	60,056	17,273
Cash and cash equivalents	200,004	152,541
Investment securities, available-for-sale	1,778,243	2,425,477
Investment securities, held-to-maturity	648,313	675,674
Total investment securities	2,426,556	3,101,151
Loans held for sale	38,833	72,927
Loans receivable	6,577,824	5,684,463
Allowance for loan and lease losses	(129,568)	(129,572)
Loans receivable, net	6,448,256	5,554,891
Premises and equipment, net	177,348	176,198
Other real estate owned	14,269	20,954
Accrued interest receivable	44,462	45,832
Deferred tax asset	38,344	67,121
Core deposit intangible, net	14,184	12,347
Goodwill	177,811	147,053
Non-marketable equity securities	29,884	25,550
Other assets	96,398	74,035
Total assets	9,706,349	9,450,600
Liabilities
Non-interest bearing deposits	2,311,902	2,041,852
Interest bearing deposits	5,267,845	5,330,427
Securities sold under agreements to repurchase	362,573	473,650
Federal Home Loan Bank advances	353,995	251,749
Other borrowed funds	8,224	4,440
Subordinated debentures	126,135	125,991
Accrued interest payable	3,450	3,584
Other liabilities	73,168	102,038
Total liabilities	8,507,292	8,333,731
Stockholders' Equity
Preferred shares, $0.01 par value per share, 1,000,000 shares authorized, none issued or outstanding	0	0
Common stock, $0.01 par value per share, 117,187,500 shares authorized	780	765
Paid-in capital	797,997	749,107
Retained earnings - substantially restricted	402,259	374,379
Accumulated other comprehensive loss	(1,979)	(7,382)
Total stockholders’ equity	1,199,057	1,116,869
Total liabilities and stockholders’ equity	$ 9,706,349	$ 9,450,600
Number of common stock shares issued and outstanding	78,006,956	76,525,402

Consolidated Statements of Fin3

Consolidated Statements of Financial Condition (Parenthetical)	Dec. 31, 2017$ / sharesshares
Statement of Financial Position [Abstract]
Preferred shares, par value | $ / shares	$ 0.01
Preferred shares, authorized	1,000,000
Preferred shares, issued	0
Preferred shares, outstanding	0
Common stock, par value | $ / shares	$ 0.01
Common stock, shares authorized	117,187,500

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest Income
Investment securities	$ 81,968	$ 90,392	$ 91,086
Residential real estate loans	33,114	33,410	32,153
Commercial loans	227,356	188,949	164,966
Consumer and other loans	32,584	31,402	31,476
Total interest income	375,022	344,153	319,681
Interest Expense
Deposits	16,793	18,402	16,138
Securities sold under agreements to repurchase	1,858	1,207	1,021
Federal Home Loan Bank advances	6,748	6,221	8,841
Other borrowed funds	79	67	81
Subordinated debentures	4,386	3,734	3,194
Total interest expense	29,864	29,631	29,275
Net Interest Income	345,158	314,522	290,406
Provision for loan losses	10,824	2,333	2,284
Net interest income after provision for loan losses	334,334	312,189	288,122
Non-Interest Income
Service charges and other fees	67,717	62,405	59,286
Miscellaneous loan fees and charges	4,360	4,613	4,276
Gain on sale of loans	30,439	33,606	26,389
(Loss) gain on sale of investments	(660)	(1,463)	19
Other income	10,383	8,157	8,791
Total non-interest income	112,239	107,318	98,761
Non-Interest Expense
Compensation and employee benefits	160,506	151,697	134,382
Occupancy and equipment	26,631	25,979	25,483
Advertising and promotions	8,405	8,433	8,661
Data processing	14,150	14,390	11,244
Other real estate owned	1,909	2,895	3,693
Regulatory assessments and insurance	4,431	4,780	5,283
Core deposit intangible amortization	2,494	2,970	2,964
Other expense	47,045	47,570	45,047
Total non-interest expense	265,571	258,714	236,757
Income Before Income Taxes	181,002	160,793	150,126
Federal and state income tax expense	64,625	39,662	33,999
Net Income	$ 116,377	$ 121,131	$ 116,127
Basic earnings per share	$ 1.50	$ 1.59	$ 1.54
Diluted earnings per share	1.50	1.59	1.54
Dividends declared per share	$ 1.14	$ 1.10	$ 1.05
Average outstanding shares - basic	77,537,664	76,278,463	75,542,455
Average outstanding shares - diluted	77,607,605	76,341,836	75,595,581

Statements of Comprehensive Inc

Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net Income	$ 116,377	$ 121,131	$ 116,127
Other Comprehensive Income (Loss), Net of Tax
Unrealized gains (losses) on available-for-sale securities	3,428	(21,407)	(22,845)
Reclassification adjustment for losses (gains) included in net income	636	1,335	(69)
Net unrealized gains (losses) on available-for-sale securities	4,064	(20,072)	(22,914)
Tax effect	(1,563)	7,776	8,904
Net of tax amount	2,501	(12,296)	(14,010)
Unrealized gains (losses) on derivatives used for cash flow hedges	444	(1,643)	(7,857)
Reclassification adjustment for losses included in net income	4,892	6,417	5,025
Net unrealized gains (losses) on derivatives used for cash flow hedges	5,336	4,774	(2,832)
Tax effect	(2,083)	(1,849)	1,087
Net of tax amount	3,253	2,925	(1,745)
Total other comprehensive income (loss), net of tax	5,754	(9,371)	(15,755)
Total Comprehensive Income	$ 122,131	$ 111,760	$ 100,372

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Paid-in Capital	Retained Earnings Substantially Restricted	Accumulated Other Comprehensive Income (Loss)
Balance, shares at Dec. 31, 2014		75,026,092
Balance at Dec. 31, 2014	$ 1,028,047	$ 750	$ 708,356	$ 301,197	$ 17,744
Net income	116,127			116,127
Other comprehensive income (loss)	(15,755)				(15,755)
Cash dividends declared	(79,792)			(79,792)
Stock issued in connection with acquisitions, shares		997,850
Stock issued in connection with acquisitions, amount	25,939	$ 10	25,929
Stock issuances under stock incentive plans, shares		62,346
Stock issuances under stock incentive plans, value	17	$ 1	16
Stock-based compensation and related taxes	2,067		2,067
Balance, shares at Dec. 31, 2015		76,086,288
Balance at Dec. 31, 2015	1,076,650	$ 761	736,368	337,532	1,989
Net income	121,131			121,131
Other comprehensive income (loss)	(9,371)				(9,371)
Cash dividends declared	(84,284)			(84,284)
Stock issued in connection with acquisitions, shares		349,545
Stock issued in connection with acquisitions, amount	10,465	$ 3	10,462
Stock issuances under stock incentive plans, shares		89,569
Stock issuances under stock incentive plans, value	0	$ 1	(1)
Stock-based compensation and related taxes	$ 2,278		2,278
Balance, shares at Dec. 31, 2016	76,525,402	76,525,402
Balance at Dec. 31, 2016	$ 1,116,869	$ 765	749,107	374,379	(7,382)
Net income	116,377			116,377
Other comprehensive income (loss)	5,754			351	5,403
Cash dividends declared	(88,848)			(88,848)
Stock issued in connection with acquisitions, shares		1,381,661
Stock issued in connection with acquisitions, amount	46,673	$ 14	46,659
Stock issuances under stock incentive plans, shares		99,893
Stock issuances under stock incentive plans, value	0	$ 1	(1)
Stock-based compensation and related taxes	$ 2,232		2,232
Balance, shares at Dec. 31, 2017	78,006,956	78,006,956
Balance at Dec. 31, 2017	$ 1,199,057	$ 780	$ 797,997	$ 402,259	$ (1,979)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash dividends declared per share	$ 1.14	$ 1.10	$ 1.05
Retained Earnings Substantially Restricted
Cash dividends declared per share	$ 1.14	$ 1.10	$ 1.05

Consolidated Statements of Cash

Consolidated Statements of Cash Flows $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)		Dec. 31, 2016USD ($)		Dec. 31, 2015USD ($)
Operating Activities
Net income	$ 116,377		$ 121,131		$ 116,127
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	10,824		2,333		2,284
Net amortization of investment securities premiums and discounts	20,026		26,210		26,709
Net (accretion) amortization of purchase accounting adjustments	(5,131)		(2,252)		1,264
Amortization of debt modification costs	471		0		0
Loans held for sale originated or acquired	(889,212)		(1,098,864)		(888,676)
Proceeds from sales of loans held for sale	984,506		1,155,186		925,353
Gain on sale of loans	(30,439)		(33,606)		(26,389)
Loss (gain) on sale of investments	660		1,463		(19)
Bank-owned life insurance income, net	(1,395)		(1,142)		(1,137)
Stock-based compensation expense, net of tax benefits	2,952		1,844		1,695
Depreciation of premises and equipment	14,758		15,294		14,365
(Gain) loss on sale of other real estate owned and write-downs, net	(1,641)		1,217		938
Deferred tax expense (benefit)	25,887	[1]	(82)	[1]	(4,080)	[1]
Core deposit intangible amortization	2,494		2,970		2,964
Amortization of investments in variable interest entities	4,692		2,578		3,297
Net decrease (increase) in accrued interest receivable	2,466		(1,144)		(2,377)
Net decrease in other assets	1,139		6,621		2,701
Net (decrease) increase in accrued interest payable	(135)		60		(828)
Net (decrease) increase in other liabilities	(4,558)		(6,730)		2,580
Net cash provided by operating activities	254,741		193,087		176,771
Investing Activities
Sales of available-for-sale securities	247,748		62,817		136,777
Maturities, prepayments and calls of available-for-sale securities	446,695		662,003		663,828
Purchases of available-for-sale securities	(36,239)		(585,064)		(961,224)
Maturities, prepayments and calls of held-to-maturity securities	25,187		25,405		20,997
Purchases of held-to-maturity securities	0		(1,222)		(203,554)
Principal collected on loans	2,099,292		1,781,534		1,736,198
Loans originated or acquired	(2,740,281)		(2,375,136)		(2,112,154)
Net additions to premises and equipment	(10,128)		(8,306)		(18,224)
Proceeds from sale of other real estate owned	12,335		10,145		10,278
Proceeds from sale of non-marketable equity securities	68,610		73,611		38,607
Purchases of non-marketable equity securities	(71,396)		(67,594)		(10,837)
Proceeds from bank-owned life insurance	437		437		1,143
Investments in variable interest entities	(14,514)		(6,644)		(4,576)
Net cash (paid) received in acquisitions	(4,091)		6,701		21,427
Net cash provided by (used in) investing activities	23,655		(421,313)		(681,314)
Financing Activities
Net (decrease) increase in deposits	(89,397)		368,006		215,895
Net (decrease) increase in securities sold under agreements to repurchase	(111,077)		50,236		24,951
Net increase (decrease) in short-term Federal Home Loan Bank advances	137,200		(100,000)		140,000
Proceeds from long-term Federal Home Loan Bank advances	150,000		0		49,816
Repayments of long-term Federal Home Loan Bank advances	(208,192)		(45,567)		(94,621)
Net increase (decrease) in other borrowed funds	3,784		(521)		(709)
Cash dividends paid	(111,720)		(84,040)		(79,456)
Tax withholding payments for stock-based compensation	(1,531)		(600)		(489)
Net cash (used in) provided by financing activities	(230,933)		187,514		255,387
Net increase (decrease) in cash and cash equivalents	47,463		(40,712)		(249,156)
Cash and cash equivalents at beginning of period	152,541		193,253		442,409
Cash and cash equivalents at end of period	200,004		152,541		193,253
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest	30,000		29,576		30,103
Cash paid during the period for income taxes	40,219		36,225		39,622
Supplemental Disclosure of Non-Cash Investing Activities
Sale and refinancing of other real estate owned	553		728		446
Transfer of loans to other real estate owned	4,466		5,198		7,989
Dividends declared but not paid	265		23,137		22,893
Fair value of common stock shares issued	46,673		10,465		25,939
Cash consideration for outstanding shares	17,342		3,475		28,364
Fair value of assets acquired	355,230		69,750		434,963
Liabilities assumed	$ 321,824		$ 62,225		$ 391,592
[1]	Includes tax benefit of operating loss carryforwards of $644,000, $571,000 and $391,000 for the years ended December 31, 2017, 2016, and 2015, respectively.

Nature of Operations and Summar

Nature of Operations and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations and Summary of Significant Accounting Policies	Nature of Operations and Summary of Significant Accounting Policies General Glacier Bancorp, Inc. (“Company”) is a Montana corporation headquartered in Kalispell, Montana. The Company provides a full range of banking services to individuals and businesses in Montana, Idaho, Utah, Washington, Wyoming, Colorado and Arizona through its wholly-owned bank subsidiary, Glacier Bank (“Bank”). The Company offers a wide range of banking products and services, including: 1) retail banking; 2) business banking; 3) real estate, commercial, agriculture and consumer loans; and 4) mortgage origination services. The Company serves individuals, small to medium-sized businesses, community organizations and public entities. The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of income and expenses during the reporting period. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change include: 1) the determination of the allowance for loan and lease losses (“ALLL” or “allowance”); 2) the valuation of investment securities; 3) the valuation of real estate acquired in connection with foreclosures or in satisfaction of loans; and 4) the evaluation of goodwill impairment. For the determination of the ALLL and real estate valuation estimates, management obtains independent appraisals (new or updated) for significant items. Estimates relating to investment valuations are obtained from independent third parties. Estimates relating to the evaluation of goodwill for impairment are determined based on internal calculations using significant independent party inputs. Principles of Consolidation The consolidated financial statements of the Company include the parent holding company and the Bank. The Bank consists of fourteen bank divisions, a treasury division, an information technology division and a centralized mortgage division. The treasury division includes the Bank’s investment portfolio and wholesale borrowings, the information technology division includes the Bank’s internal data processing, and the centralized mortgage division includes mortgage loan servicing and secondary market sales. The Bank divisions operate under separate names, management teams and advisory directors. The Company considers the Bank to be its sole operating segment as the Bank 1) engages in similar bank business activity from which it earns revenues and incurs expenses; 2) the operating results of the Bank are regularly reviewed by the Chief Executive Officer (“CEO”) (i.e., the chief operating decision maker) who makes decisions about resources to be allocated to the Bank; and 3) financial information is available for the Bank. All significant inter-company transactions have been eliminated in consolidation. The Bank has subsidiary interests in variable interest entities (“VIE”) for which the Bank has both the power to direct the VIE’s significant activities and the obligation to absorb losses or right to receive benefits of the VIE that could potentially be significant to the VIE. These subsidiary interests are included in the Company’s consolidated financial statements. The Bank also has subsidiary interests in VIEs for which the Bank does not have a controlling financial interest and is not the primary beneficiary. These subsidiary interests are not included in the Company’s consolidated financial statements. The parent holding company owns non-bank subsidiaries that have issued trust preferred securities as Tier 1 capital instruments. The trust subsidiaries are not included in the Company’s consolidated financial statements. The Company's investments in the trust subsidiaries are included in non-marketable equity securities on the Company's statements of financial condition. In April 2017, the Company completed its acquisition of TFB Bancorp, Inc. and its wholly-owned subsidiary, The Foothills Bank, a community bank based in Yuma, Arizona (collectively, “Foothills”). In August 2016, the Company completed its acquisition of Treasure State Bank (“TSB”), a community bank based in Missoula, Montana. In October 2015, the Company completed its acquisition of Cañon Bank Corporation and its wholly-owned subsidiary, Cañon National Bank, a community bank based in Cañon City, Colorado (collectively, “Cañon”). In February 2015, the Company completed its acquisition of Montana Community Banks, Inc. and its wholly-owned subsidiary, Community Bank, Inc., a community bank based in Ronan, Montana (collectively, “CB”). The transactions were accounted for using the acquisition method, and their results of operations have been included in the Company’s consolidated financial statements as of the acquisition dates. For additional information relating to recent mergers and acquisitions, see Note 22. In January 2018, the Company acquired the outstanding common stock of Columbine Capital Corp., and its wholly-owned subsidiary, Collegiate Peaks Bank, a community bank based in Buena Vista, Colorado (collectively, “Collegiate”). As of December 31, 2017, Collegiate had total assets of $532,958,000 , gross loans of $345,687,000 and total deposits of $463,970,000 . For additional information relating to this subsequent event, see Note 23. Note 1. Nature of Operations and Summary of Significant Accounting Policies (continued) In October 2017, the Company announced the signing of a definitive agreement to acquire Inter-Mountain Bancorp, Inc. and its wholly-owned subsidiary, First Security Bank, a community bank based in Bozeman, Montana (collectively, “FSB”). FSB provides banking services to individuals and businesses throughout Montana with banking offices located in Bozeman, Belgrade, Big Sky, Choteau, Fairfield, Fort Benton, Three Forks, Vaughn and West Yellowstone. As of December 31, 2017, FSB had total assets of $1,027,685,000 , gross loans of $639,880,000 and total deposits of $891,390,000 . Upon closing of the transaction, which is anticipated to take place in February 2018, FSB will become a new bank division headquartered in Bozeman. Big Sky Western Bank, the Bank’s existing Bozeman-based division will combine with the new FSB division. The agriculture-focused northern branches of FSB, located in the area known as the Golden Triangle, will combine with the Bank’s First Bank of Montana division. Cash and Cash Equivalents Cash and cash equivalents include cash on hand, cash held as demand deposits at various banks and the Federal Reserve Bank (“FRB”), interest bearing deposits, federal funds sold, and liquid investments with original maturities of three months or less. The Bank is required to maintain an average reserve balance with either the FRB or in the form of cash on hand. The required reserve balance at December 31, 2017 was $10,916,000 . Investment Securities Debt securities for which the Company has the positive intent and ability to hold to maturity are classified as held-to-maturity and are carried at amortized cost. Debt and equity securities held primarily for the purpose of selling in the near term are classified as trading securities and are reported at fair value, with unrealized gains and losses included in income. Debt and equity securities not classified as held-to-maturity or trading are classified as available-for-sale and are reported at fair value with unrealized gains and losses, net of income taxes, as a separate component of other comprehensive income (“OCI”). Premiums and discounts on investment securities are amortized or accreted into income using a method that approximates the interest method. The objective of the interest method is to calculate periodic interest income at a constant effective yield. The Company does not have any investment securities classified as trading securities. The Company reviews and analyzes the various risks that may be present within the investment portfolio on an ongoing basis, including market risk and credit risk. Market risk is the risk to an entity’s financial condition resulting from adverse changes in the value of its holdings arising from movements in interest rates, foreign exchange rates, equity prices or commodity prices. The Company assesses the market risk of individual securities as well as the investment portfolio as a whole. Credit risk, broadly defined, is the risk that an issuer or counterparty will fail to perform on an obligation. A security is investment grade if the issuer has an adequate capacity to meet its commitment over the expected life of the investment, i.e., the risk of default is low and full and timely repayment of interest and principal is expected. To determine investment grade status for securities, the Company conducts due diligence of the creditworthiness of the issuer or counterparty prior to acquisition and ongoing thereafter consistent with the risk characteristics of the security and the overall risk of the investment portfolio. Credit quality due diligence takes into account the extent to which a security is guaranteed by the U.S. government and other agencies of the U.S. government. The depth of the due diligence is based on the complexity of the structure, the size of the security, and takes into account material positions and specific groups of securities or stratifications for analysis and review of similar risk positions. The due diligence includes consideration of payment performance, collateral adequacy, internal analyses, third party research and analytics, external credit ratings and default statistics. For additional information relating to investment securities, see Note 2. Temporary versus Other-Than-Temporary Impairment The Company assesses individual securities in its investment portfolio for impairment at least on a quarterly basis, and more frequently when economic or market conditions warrant. An investment is impaired if the fair value of the security is less than its carrying value at the financial statement date. If impairment is determined to be other-than-temporary, an impairment loss is recognized by reducing the amortized cost for the credit loss portion of the impairment with a corresponding charge to earnings for a like amount. In evaluating impaired securities for other-than-temporary impairment losses, management considers 1) the severity and duration of the impairment; 2) the credit ratings of the security; and 3) the overall deal structure, including the Company’s position within the structure, the overall and near term financial performance of the issuer and underlying collateral, delinquencies, defaults, loss severities, recoveries, prepayments, cumulative loss projections, discounted cash flows and fair value estimates. Note 1. Nature of Operations and Summary of Significant Accounting Policies (continued) In evaluating debt securities for other-than-temporary impairment losses, management assesses whether the Company intends to sell the security or if it is more-likely-than-not that the Company will be required to sell the debt security. In so doing, management considers contractual constraints, liquidity, capital, asset/liability management and securities portfolio objectives. If impairment is determined to be other-than-temporary and the Company does not intend to sell a debt security, and it is more-likely-than-not the Company will not be required to sell the security before recovery of its cost basis, it recognizes the credit component of an other-than-temporary impairment of a debt security in earnings and the remaining portion (noncredit portion) in OCI, net of tax. For held-to-maturity debt securities, the amount of an other-than-temporary impairment recorded in OCI for the noncredit portion of a previous other-than-temporary impairment is amortized prospectively, as an increase to the carrying amount of the security, over the remaining life of the security on the basis of the timing of future estimated cash flows of the security. If impairment is determined to be other-than-temporary and the Company intends to sell a debt security or it is more-likely-than-not the Company will be required to sell the security before recovery of its cost basis, it recognizes the entire amount of the other-than-temporary impairment in earnings. For debt securities with other-than-temporary impairment, the previous amortized cost basis less the other-than-temporary impairment recognized in earnings shall be the new amortized cost basis of the security. In subsequent periods, the Company accretes into interest income the difference between the new amortized cost basis and cash flows expected to be collected prospectively over the life of the debt security. Loans Held for Sale Loans held for sale generally consist of long-term, fixed rate, conforming, single-family residential real estate loans intended to be sold on the secondary market. Loans held for sale may be carried at the lower of cost or estimated fair value in the aggregate basis, or at fair value where the Company has elected the fair value option. When an election is made to carry the loans held for sale at fair value, the fair value includes the servicing value of the loans and any change in fair value is recognized in non-interest income. Fair value elections are made at the time of origination or purchase based on the Company’s fair value election policy. Beginning in 2017, the Company elected fair value accounting for all of its loans held for sale. Loans Receivable Loans that are intended to be held-to-maturity are reported at the unpaid principal balance less net charge-offs and adjusted for deferred fees and costs on originated loans and unamortized premiums or discounts on acquired loans. Fees and costs on originated loans and premiums or discounts on acquired loans are deferred and subsequently amortized or accreted as a yield adjustment over the expected life of the loan utilizing the interest method. The objective of the interest method is to calculate periodic interest income at a constant effective yield. When a loan is paid off prior to maturity, the remaining fees and costs on originated loans and premiums or discounts on acquired loans are immediately recognized into interest income. The Company’s loan segments, which are based on the purpose of the loan, include residential real estate, commercial, and consumer loans. The Company’s loan classes, a further disaggregation of segments, include residential real estate loans (residential real estate segment), commercial real estate and other commercial loans (commercial segment), and home equity and other consumer loans (consumer segment). Loans that are thirty days or more past due based on payments received and applied to the loan are considered delinquent. Loans are designated non-accrual and the accrual of interest is discontinued when the collection of the contractual principal or interest is unlikely. A loan is typically placed on non-accrual when principal or interest is due and has remained unpaid for ninety days or more. When a loan is placed on non-accrual status, interest previously accrued but not collected is reversed against current period interest income. Subsequent payments on non-accrual loans are applied to the outstanding principal balance if doubt remains as to the ultimate collectability of the loan. Interest accruals are not resumed on partially charged-off impaired loans. For other loans on nonaccrual, interest accruals are resumed on such loans only when they are brought fully current with respect to interest and principal and when, in the judgment of management, the loans are estimated to be fully collectible as to both principal and interest. Note 1. Nature of Operations and Summary of Significant Accounting Policies (continued) The Company considers impaired loans to be the primary credit quality indicator for monitoring the credit quality of the loan portfolio. Loans are designated impaired when, based upon current information and events, it is probable that the Company will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement and, therefore, the Company has serious doubts as to the ability of such borrowers to fulfill the contractual obligation. Impaired loans include non-performing loans (i.e., non-accrual loans and accruing loans ninety days or more past due) and accruing loans under ninety days past due where it is probable payments will not be received according to the loan agreement (e.g., troubled debt restructuring). Interest income on accruing impaired loans is recognized using the interest method. The Company measures impairment on a loan-by-loan basis in the same manner for each class within the loan portfolio. An insignificant delay or shortfall in the amounts of payments would not cause a loan or lease to be considered impaired. The Company determines the significance of payment delays and shortfalls on a case-by-case basis, taking into consideration all of the facts and circumstances surrounding the loan and the borrower, including the length and reasons for the delay, the borrower’s prior payment record, and the amount of the shortfall in relation to the principal and interest due. A restructured loan is considered a troubled debt restructuring (“TDR”) if the creditor, for economic or legal reasons related to the debtor’s financial difficulties, grants a concession to the debtor that it would not otherwise consider. The Company periodically enters into restructure agreements with borrowers whereby the loans were previously identified as TDRs. When such circumstances occur, the Company carefully evaluates the facts of the subsequent restructure to determine the appropriate accounting and under certain circumstances it may be acceptable not to account for the subsequently restructured loan as a TDR. When assessing whether a concession has been granted by the Company, any prior forgiveness on a cumulative basis is considered a continuing concession. A TDR loan is considered an impaired loan and a specific valuation allowance is established when the fair value of the collateral-dependent loan or present value of the loan’s expected future cash flows (discounted at the loan’s effective interest rate based on the original contractual rate) is lower than the carrying value of the impaired loan. The Company has made the following types of loan modifications, some of which were considered a TDR: • reduction of the stated interest rate for the remaining term of the debt; • extension of the maturity date(s) at a stated rate of interest lower than the current market rate for newly originated debt having similar risk characteristics; and • reduction of the face amount of the debt as stated in the debt agreements. The Company recognizes that while borrowers may experience deterioration in their financial condition, many continue to be creditworthy customers who have the willingness and capacity for debt repayment. In determining whether non-restructured or unimpaired loans issued to a single or related party group of borrowers should continue to accrue interest when the borrower has other loans that are impaired or are TDRs, the Company on a quarterly or more frequent basis performs an updated and comprehensive assessment of the willingness and capacity of the borrowers to timely and ultimately repay their total debt obligations, including contingent obligations. Such analysis takes into account current financial information about the borrowers and financially responsible guarantors, if any, including for example: • analysis of global, i.e., aggregate debt service for total debt obligations; • assessment of the value and security protection of collateral pledged using current market conditions and alternative market assumptions across a variety of potential future situations; and • loan structures and related covenants. For additional information relating to loans, see Note 3. Allowance for Loan and Lease Losses Based upon management’s analysis of the Company’s loan portfolio, the balance of the ALLL is an estimate of probable credit losses known and inherent within the Bank’s loan portfolio as of the date of the consolidated financial statements. The ALLL is analyzed at the loan class level and is maintained within a range of estimated losses. Determining the adequacy of the ALLL involves a high degree of judgment and is inevitably imprecise as the risk of loss is difficult to quantify. The determination of the ALLL and the related provision for loan losses is a critical accounting estimate that involves management’s judgments about known relevant internal and external environmental factors that affect loan losses. The balance of the ALLL is highly dependent upon management’s evaluations of borrowers’ current and prospective performance, appraisals and other variables affecting the quality of the loan portfolio. Individually significant loans and major lending areas are reviewed periodically to determine potential problems at an early date. Changes in management’s estimates and assumptions are reasonably possible and may have a material impact upon the Company’s consolidated financial statements, results of operations or capital. Note 1. Nature of Operations and Summary of Significant Accounting Policies (continued) Risk characteristics considered in the ALLL analysis applicable to each loan class within the Company's loan portfolio are as follows: Residential Real Estate. Residential real estate loans are secured by owner-occupied 1-4 family residences. Repayment of these loans is primarily dependent on the personal income and credit rating of the borrowers. Credit risk in these loans is impacted by economic conditions within the Company’s market areas that affect the value of the property securing the loans and affect the borrowers' personal incomes. Mitigating risk factors for this loan class include a large number of borrowers, geographic dispersion of market areas and the loans are originated for relatively smaller amounts. Commercial Real Estate . Commercial real estate loans typically involve larger principal amounts, and repayment of these loans is generally dependent on the successful operation of the property securing the loan and/or the business conducted on the property securing the loan. Credit risk in these loans is impacted by the creditworthiness of a borrower, valuation of the property securing the loan and conditions within the local economies in the Company’s diverse, geographic market areas. Commercial . Commercial loans consist of loans to commercial customers for use in financing working capital needs, equipment purchases and business expansions. The loans in this category are repaid primarily from the cash flow of a borrower’s principal business operation. Credit risk in these loans is driven by creditworthiness of a borrower and the economic conditions that impact the cash flow stability from business operations across the Company’s diverse, geographic market areas. Home Equity . Home equity loans consist of junior lien mortgages and first and junior lien lines of credit (revolving open-end and amortizing closed-end) secured by owner-occupied 1-4 family residences. Repayment of these loans is primarily dependent on the personal income and credit rating of the borrowers. Credit risk in these loans is impacted by economic conditions within the Company’s market areas that affect the value of the residential property securing the loans and affect the borrowers' personal incomes. Mitigating risk factors for this loan class are a large number of borrowers, geographic dispersion of market areas and the loans are originated for terms that range from 10 years to 15 years . Other Consumer . The other consumer loan portfolio consists of various short-term loans such as automobile loans and loans for other personal purposes. Repayment of these loans is primarily dependent on the personal income of the borrowers. Credit risk is driven by consumer economic factors (such as unemployment and general economic conditions in the Company’s diverse, geographic market area) and the creditworthiness of a borrower. The ALLL consists of a specific valuation allowance component and a general valuation allowance component. The specific component relates to loans that are determined to be impaired and individually evaluated for impairment. The Company measures impairment on a loan-by-loan basis based on the present value of expected future cash flows discounted at the loan’s effective interest rate, except when it is determined that repayment of the loan is expected to be provided solely by the underlying collateral. For impairment based on expected future cash flows, the Company considers all information available as of a measurement date, including past events, current conditions, potential prepayments, and estimated cost to sell when such costs are expected to reduce the cash flows available to repay or otherwise satisfy the loan. For alternative ranges of cash flows, the likelihood of the possible outcomes is considered in determining the best estimate of expected future cash flows. The effective interest rate for a loan restructured in a TDR is based on the original contractual rate. For collateral-dependent loans and real estate loans for which foreclosure or a deed-in-lieu of foreclosure is probable, impairment is measured by the fair value of the collateral, less estimated cost to sell. The fair value of the collateral is determined primarily based upon appraisal or evaluation of the underlying real property value. The general valuation allowance component relates to probable credit losses inherent in the balance of the loan portfolio based on historical loss experience, adjusted for changes in trends and conditions of qualitative or environmental factors. The historical loss experience is based on the previous twelve quarters loss experience by loan class adjusted for risk characteristics in the existing loan portfolio. The same trends and conditions are evaluated for each class within the loan portfolio; however, the risk characteristics are weighted separately at the individual class level based on the Company’s judgment and experience. Note 1. Nature of Operations and Summary of Significant Accounting Policies (continued) The changes in trends and conditions evaluated for each class within the loan portfolio include the following: • changes in lending policies and procedures, including changes in underwriting standards and collection, charge-off, and recovery practices not considered elsewhere in estimating credit losses; • changes in global, national, regional, and local economic and business conditions and developments that affect the collectability of the portfolio, including the condition of various market segments; • changes in the nature and volume of the portfolio and in the terms of loans; • changes in experience, ability, and depth of lending management and other relevant staff; • changes in the volume and severity of past due and nonaccrual loans; • changes in the quality of the Company’s loan review system; • changes in the value of underlying collateral for collateral-dependent loans; • the existence and effect of any concentrations of credit, and changes in the level of such concentrations; and • the effect of other external factors such as competition and legal and regulatory requirements on the level of estimated credit losses in the Company’s existing portfolio. The ALLL is increased by provisions for loan losses which are charged to expense. The portions of loan and overdraft balances determined by management to be uncollectible are charged off as a reduction of the ALLL and recoveries of amounts previously charged off are credited as an increase to the ALLL. The Company’s charge-off policy is consistent with bank regulatory standards. Consumer loans generally are charged off when the loan becomes over 120 days delinquent. Real estate acquired as a result of foreclosure or by deed-in-lieu of foreclosure is classified as OREO until such time as it is sold. At acquisition date, the assets and liabilities of acquired banks are recorded at their estimated fair values which results in no ALLL carried over from acquired banks. Subsequent to acquisition, an allowance will be recorded on the acquired loan portfolios for further credit deterioration, if any. Premises and Equipment Premises and equipment are accounted for at cost less depreciation. Depreciation is computed on a straight-line method over the estimated useful lives or the term of the related lease. The estimated useful life for office buildings is 15 - 40 years and the estimated useful life for furniture, fixtures, and equipment is 3 - 10 years. Interest is capitalized for any significant building projects. For additional information relating to premises and equipment, see Note 4. Leases The Company leases certain land, premises and equipment from third parties under operating and capital leases. The lease payments for operating lease agreements are recognized on a straight-line basis. The present value of the future minimum rental payments for capital leases is recognized as an asset when the lease is formed. Lease improvements incurred at the inception of the lease are recorded as an asset and depreciated over the initial term of the lease and lease improvements incurred subsequently are depreciated over the remaining term of the lease. For additional information relating to leases, see Note 4. Other Real Estate Owned Property acquired by foreclosure or deed-in-lieu of foreclosure is initially recorded at fair value, less estimated selling cost, at acquisition date (i.e., cost of the property). The Company is considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loan upon the occurrence of either the Company obtaining legal title to the property or the borrower conveying all interest in the property through a deed-in-lieu or similar agreement. Fair value is determined as the amount that could be reasonably expected in a current sale between a willing buyer and a willing seller in an orderly transaction between market participants at the measurement date. Subsequent to the initial acquisition, if the fair value of the asset, less estimated selling cost, is less than the cost of the property, a loss is recognized in other expense and the asset carrying value is reduced. Gain or loss on disposition of other real estate owned (“OREO”) is recorded in non-interest income or non-interest expense, respectively. In determining the fair value of the properties on the date of transfer and any subsequent estimated losses of net realizable value, the fair value of other real estate acquired by foreclosure or deed-in-lieu of foreclosure is determined primarily based upon appraisal or evaluation of the underlying property value. Long-lived Assets Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. An asset is deemed impaired if the sum of the expected future cash flows is less than the carrying amount of the asset. If impaired, an impairment loss is recognized in other expense to reduce the carrying value of the asset to fair value. At December 31, 2017 and 2016 , no long-lived assets were considered materially impaired. Note 1. Nature of Operations and Summary of Significant Accounting Policies (continued) Business Combinations and Intangible Assets Acquisition accounting requires the total purchase price to be allocated to the estimated fair values of assets acquired and liabilities assumed, including certain intangible assets. Goodwill is recorded if the purchase price exceeds the net fair value of assets acquired and a bargain purchase gain is recorded in other income if the net fair value of assets acquired exceeds the purchase price. Adjustment of the allocated purchase price may be related to fair value estimates for which all information has not been obtained of the acquired entity known or discovered during the allocation period, the period of time required to identify and measure the fair values of the assets and liabilities acquired in the business combination. The allocation period is generally limited to one year following consummation of a business combination. Core deposit intangible represents the intangible value of

Investment Securities

Investment Securities	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Investment Securities	Investment Securities The following tables present the amortized cost, the gross unrealized gains and losses and the fair value of the Company’s investment securities: December 31, 2017 Amortized Cost Gross Unrealized Fair Value (Dollars in thousands) Gains Losses Available-for-sale U.S. government and federal agency $ 31,216 54 (143 ) 31,127 U.S. government sponsored enterprises 19,195 — (104 ) 19,091 State and local governments 614,366 20,299 (5,164 ) 629,501 Corporate bonds 216,443 802 (483 ) 216,762 Residential mortgage-backed securities 785,960 1,253 (7,930 ) 779,283 Commercial mortgage-backed securities 104,324 25 (1,870 ) 102,479 Total available-for-sale 1,771,504 22,433 (15,694 ) 1,778,243 Held-to-maturity State and local governments 648,313 20,346 (8,573 ) 660,086 Total held-to-maturity 648,313 20,346 (8,573 ) 660,086 Total investment securities $ 2,419,817 42,779 (24,267 ) 2,438,329 December 31, 2016 Amortized Cost Gross Unrealized Fair Value (Dollars in thousands) Gains Losses Available-for-sale U.S. government and federal agency $ 39,554 15 (162 ) 39,407 U.S. government sponsored enterprises 19,557 55 (42 ) 19,570 State and local governments 775,395 20,941 (9,963 ) 786,373 Corporate bonds 471,569 1,175 (793 ) 471,951 Residential mortgage-backed securities 1,014,518 2,744 (9,747 ) 1,007,515 Commercial mortgage-backed securities 102,209 30 (1,578 ) 100,661 Total available-for-sale 2,422,802 24,960 (22,285 ) 2,425,477 Held-to-maturity State and local governments 675,674 21,400 (7,985 ) 689,089 Total held-to-maturity 675,674 21,400 (7,985 ) 689,089 Total investment securities $ 3,098,476 46,360 (30,270 ) 3,114,566 Note 2. Investment Securities (continued) The following table presents the amortized cost and fair value of available-for-sale and held-to-maturity securities by contractual maturity at December 31, 2017 . Actual maturities may differ from expected or contractual maturities since issuers have the right to prepay obligations with or without prepayment penalties. December 31, 2017 Available-for-Sale Held-to-Maturity (Dollars in thousands) Amortized Cost Fair Value Amortized Cost Fair Value Due within one year $ 69,596 69,650 — — Due after one year through five years 228,415 228,881 2,108 2,136 Due after five years through ten years 228,766 236,318 86,741 88,264 Due after ten years 354,443 361,632 559,464 569,686 881,220 896,481 648,313 660,086 Mortgage-backed securities 1 890,284 881,762 — — Total $ 1,771,504 1,778,243 648,313 660,086 ______________________________ 1 Mortgage-backed securities, which have prepayment provisions, are not assigned to maturity categories due to fluctuations in their prepayment speeds. Proceeds from sales and calls of investment securities and the associated gains and losses that have been included in earnings are listed below: Years ended (Dollars in thousands) December 31, December 31, December 31, Available-for-sale Proceeds from sales and calls of investment securities $ 280,783 212,140 167,660 Gross realized gains 1 3,369 2,459 1,877 Gross realized losses 1 (4,005 ) (3,794 ) (1,808 ) Held-to-maturity Proceeds from calls of investment securities 23,020 25,405 20,997 Gross realized gains 1 204 97 50 Gross realized losses 1 (228 ) (225 ) (100 ) ______________________________ 1 The gain or loss on the sale or call of each investment security is determined by the specific identification method. At December 31, 2017 and 2016 , the Company had investment securities with carrying values of $1,447,808,000 and $1,878,739,000 , respectively, pledged as collateral for FHLB advances, FRB discount window borrowings, securities sold under agreements to repurchase (“repurchase agreements”), interest rate swap agreements and deposits of several local government units. Note 2. Investment Securities (continued) Investment securities with an unrealized loss position are summarized as follows: December 31, 2017 Less than 12 Months 12 Months or More Total (Dollars in thousands) Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Available-for-sale U.S. government and federal agency $ 1,208 (5 ) 13,179 (138 ) 14,387 (143 ) U.S. government sponsored enterprises 14,926 (56 ) 3,425 (48 ) 18,351 (104 ) State and local governments 61,126 (689 ) 121,181 (4,475 ) 182,307 (5,164 ) Corporate bonds 99,636 (264 ) 29,034 (219 ) 128,670 (483 ) Residential mortgage-backed securities 372,175 (3,050 ) 254,721 (4,880 ) 626,896 (7,930 ) Commercial mortgage-backed securities 37,650 (469 ) 62,968 (1,401 ) 100,618 (1,870 ) Total available-for-sale $ 586,721 (4,533 ) 484,508 (11,161 ) 1,071,229 (15,694 ) Held-to-maturity State and local governments $ 21,207 (186 ) 105,486 (8,387 ) 126,693 (8,573 ) Total held-to-maturity $ 21,207 (186 ) 105,486 (8,387 ) 126,693 (8,573 ) December 31, 2016 Less than 12 Months 12 Months or More Total (Dollars in thousands) Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Available-for-sale U.S. government and federal agency $ 6,718 (24 ) 26,239 (138 ) 32,957 (162 ) U.S. government sponsored enterprises 6,049 (42 ) — — 6,049 (42 ) State and local governments 222,700 (4,949 ) 81,783 (5,014 ) 304,483 (9,963 ) Corporate bonds 174,821 (774 ) 6,141 (19 ) 180,962 (793 ) Residential mortgage-backed securities 688,811 (9,079 ) 29,957 (668 ) 718,768 (9,747 ) Commercial mortgage-backed securities 89,298 (1,578 ) — — 89,298 (1,578 ) Total available-for-sale $ 1,188,397 (16,446 ) 144,120 (5,839 ) 1,332,517 (22,285 ) Held-to-maturity State and local governments $ 117,912 (1,712 ) 86,601 (6,273 ) 204,513 (7,985 ) Total held-to-maturity $ 117,912 (1,712 ) 86,601 (6,273 ) 204,513 (7,985 ) Based on an analysis of its investment securities with unrealized losses as of December 31, 2017 and 2016 , the Company determined that none of such securities had other-than-temporary impairment and the unrealized losses were primarily the result of interest rate changes and market spreads subsequent to acquisition. The fair value of the investment securities is expected to recover as payments are received and the securities approach maturity. At December 31, 2017 , management determined that it did not intend to sell investment securities with unrealized losses, and there was no expected requirement to sell any of its investment securities with unrealized losses before recovery of their amortized cost.

Loans Receivable, Net

Loans Receivable, Net	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Loans Receivable, Net	Loans Receivable, Net The Company’s loan portfolio is comprised of three segments: residential real estate, commercial, and consumer and other loans. The loan segments are further disaggregated into the following classes: residential real estate, commercial real estate, other commercial, home equity and other consumer loans. The following table presents loans receivable for each portfolio class of loans: At or for the Years ended (Dollars in thousands) December 31, December 31, Residential real estate loans $ 720,728 674,347 Commercial loans Real estate 3,577,139 2,990,141 Other commercial 1,579,353 1,342,250 Total 5,156,492 4,332,391 Consumer and other loans Home equity 457,918 434,774 Other consumer 242,686 242,951 Total 700,604 677,725 Loans receivable 6,577,824 5,684,463 Allowance for loan and lease losses (129,568 ) (129,572 ) Loans receivable, net $ 6,448,256 5,554,891 Net deferred origination (fees) costs included in loans receivable $ (2,643 ) (1,228 ) Net purchase accounting (discounts) premiums included in loans receivable $ (16,325 ) (12,144 ) Weighted-average interest rate on loans (tax-equivalent) 4.81 % 4.77 % The following tables summarize the activity in the ALLL by portfolio segment: Year ended December 31, 2017 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Balance at beginning of period $ 129,572 12,436 65,773 37,823 7,572 5,968 Provision for loan losses 10,824 (1,521 ) 7,152 2,545 (1,103 ) 3,751 Charge-offs (19,331 ) (199 ) (6,188 ) (2,856 ) (489 ) (9,599 ) Recoveries 8,503 82 1,778 1,791 224 4,628 Balance at end of period $ 129,568 10,798 68,515 39,303 6,204 4,748 Year ended December 31, 2016 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Balance at beginning of period $ 129,697 14,427 67,877 32,525 8,998 5,870 Provision for loan losses 2,333 (1,734 ) (2,686 ) 5,164 (520 ) 2,109 Charge-offs (11,496 ) (464 ) (3,082 ) (1,778 ) (1,185 ) (4,987 ) Recoveries 9,038 207 3,664 1,912 279 2,976 Balance at end of period $ 129,572 12,436 65,773 37,823 7,572 5,968 Note 3. Loans Receivable, Net (continued) Year ended December 31, 2015 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Balance at beginning of period $ 129,753 14,680 67,799 30,891 9,963 6,420 Provision for loan losses 2,284 640 (696 ) 3,030 (480 ) (210 ) Charge-offs (7,002 ) (985 ) (1,920 ) (2,322 ) (809 ) (966 ) Recoveries 4,662 92 2,694 926 324 626 Balance at end of period $ 129,697 14,427 67,877 32,525 8,998 5,870 The following tables disclose the recorded investment in loans and the balance in the ALLL by portfolio segment: December 31, 2017 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Loans receivable Individually evaluated for impairment $ 119,994 12,399 77,536 23,032 3,755 3,272 Collectively evaluated for impairment 6,457,830 708,329 3,499,603 1,556,321 454,163 239,414 Total loans receivable $ 6,577,824 720,728 3,577,139 1,579,353 457,918 242,686 ALLL Individually evaluated for impairment $ 5,223 246 500 3,851 56 570 Collectively evaluated for impairment 124,345 10,552 68,015 35,452 6,148 4,178 Total ALLL $ 129,568 10,798 68,515 39,303 6,204 4,748 December 31, 2016 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Loans receivable Individually evaluated for impairment $ 130,263 11,612 85,634 23,950 5,934 3,133 Collectively evaluated for impairment 5,554,200 662,735 2,904,507 1,318,300 428,840 239,818 Total loans receivable $ 5,684,463 674,347 2,990,141 1,342,250 434,774 242,951 ALLL Individually evaluated for impairment $ 6,881 856 922 4,419 296 388 Collectively evaluated for impairment 122,691 11,580 64,851 33,404 7,276 5,580 Total ALLL $ 129,572 12,436 65,773 37,823 7,572 5,968 Substantially all of the Company’s loans receivable are with customers in the Company’s geographic market areas. Although the Company has a diversified loan portfolio, a substantial portion of its customers’ ability to honor their obligations is dependent upon the economic performance in the Company’s market areas. The Company is subject to regulatory limits for the amount of loans to any individual borrower and the Company is in compliance with this regulation as of December 31, 2017 and 2016 . No borrower had outstanding loans or commitments exceeding 10 percent of the Company’s consolidated stockholders’ equity as of December 31, 2017 . At December 31, 2017 , the Company had $4,189,489,000 in variable rate loans and $2,388,335,000 in fixed rate loans. At December 31, 2017 , the Company had loans of $3,836,190,000 pledged as collateral for FHLB advances and FRB discount window. There were no significant purchases or sales of portfolio loans during 2017 , 2016 and 2015 . Note 3. Loans Receivable, Net (continued) The Company has entered into transactions with its executive officers and directors and their affiliates. The aggregate amount of loans outstanding to such related parties at December 31, 2017 and 2016 was $82,350,000 and $58,438,000 , respectively. During 2017 , new loans to such related parties were $33,322,000 and repayments were $9,410,000 . In management’s opinion, such loans were made in the ordinary course of business and were made on substantially the same terms as those prevailing at the time for comparable transaction with other persons. The following tables disclose information related to impaired loans by portfolio segment: At or for the Year ended December 31, 2017 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Loans with a specific valuation allowance Recorded balance $ 17,689 2,978 4,545 8,183 186 1,797 Unpaid principal balance 18,400 3,046 4,573 8,378 199 2,204 Specific valuation allowance 5,223 246 500 3,851 56 570 Average balance 18,986 2,928 5,851 8,477 359 1,371 Loans without a specific valuation allowance Recorded balance 102,305 9,421 72,991 14,849 3,569 1,475 Unpaid principal balance 122,833 10,380 89,839 16,931 4,098 1,585 Average balance 107,945 9,834 76,427 15,129 4,734 1,821 Total Recorded balance 119,994 12,399 77,536 23,032 3,755 3,272 Unpaid principal balance 141,233 13,426 94,412 25,309 4,297 3,789 Specific valuation allowance 5,223 246 500 3,851 56 570 Average balance 126,931 12,762 82,278 23,606 5,093 3,192 At or for the Year ended December 31, 2016 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Loans with a specific valuation allowance Recorded balance $ 22,128 2,759 9,129 8,814 334 1,092 Unpaid principal balance 22,374 2,825 9,130 8,929 345 1,145 Specific valuation allowance 6,881 856 922 4,419 296 388 Average balance 26,745 4,942 10,441 9,840 257 1,265 Loans without a specific valuation allowance Recorded balance 108,135 8,853 76,505 15,136 5,600 2,041 Unpaid principal balance 131,059 9,925 94,180 17,724 7,120 2,110 Average balance 108,827 12,858 72,323 15,537 6,004 2,105 Total Recorded balance 130,263 11,612 85,634 23,950 5,934 3,133 Unpaid principal balance 153,433 12,750 103,310 26,653 7,465 3,255 Specific valuation allowance 6,881 856 922 4,419 296 388 Average balance 135,572 17,800 82,764 25,377 6,261 3,370 Interest income recognized on impaired loans for the years ended December 31, 2017 , 2016 , and 2015 was not significant. Note 3. Loans Receivable, Net (continued) The following tables present an aging analysis of the recorded investment in loans by portfolio segment: December 31, 2017 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Accruing loans 30-59 days past due $ 26,375 6,252 12,546 3,634 2,142 1,801 Accruing loans 60-89 days past due 11,312 794 5,367 3,502 987 662 Accruing loans 90 days or more past due 6,077 2,366 609 2,973 — 129 Non-accrual loans 44,833 4,924 27,331 8,298 3,338 942 Total past due and non-accrual loans 88,597 14,336 45,853 18,407 6,467 3,534 Current loans receivable 6,489,227 706,392 3,531,286 1,560,946 451,451 239,152 Total loans receivable $ 6,577,824 720,728 3,577,139 1,579,353 457,918 242,686 December 31, 2016 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Accruing loans 30-59 days past due $ 20,599 6,338 5,079 5,388 2,439 1,355 Accruing loans 60-89 days past due 5,018 1,398 754 1,352 844 670 Accruing loans 90 days or more past due 1,099 266 145 283 191 214 Non-accrual loans 49,332 4,528 30,216 8,817 5,240 531 Total past due and non-accrual loans 76,048 12,530 36,194 15,840 8,714 2,770 Current loans receivable 5,608,415 661,817 2,953,947 1,326,410 426,060 240,181 Total loans receivable $ 5,684,463 674,347 2,990,141 1,342,250 434,774 242,951 Interest income that would have been recorded on non-accrual loans if such loans had been current for the entire period would have been approximately $2,162,000 , $2,364,000 , and $2,471,000 for the years ended December 31, 2017 , 2016 , and 2015 , respectively. The following tables present TDRs that occurred during the periods presented and the TDRs that occurred within the previous twelve months that subsequently defaulted during the periods presented: Year ended December 31, 2017 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer TDRs that occurred during the period Number of loans 32 5 13 11 2 1 Pre-modification recorded balance $ 41,521 841 31,109 9,403 158 10 Post-modification recorded balance $ 38,838 841 28,426 9,403 158 10 TDRs that subsequently defaulted Number of loans 1 — — 1 — — Recorded balance $ 18 — — 18 — — Note 3. Loans Receivable, Net (continued) Year ended December 31, 2016 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer TDRs that occurred during the period Number of loans 34 — 10 21 3 — Pre-modification recorded balance $ 22,907 — 8,454 14,183 270 — Post-modification recorded balance $ 22,848 — 8,415 14,166 267 — TDRs that subsequently defaulted Number of loans 1 — — 1 — — Recorded balance $ 6 — — 6 — — Year ended December 31, 2015 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer TDRs that occurred during the period Number of loans 64 3 25 22 1 13 Pre-modification recorded balance $ 22,316 2,259 8,877 10,545 137 498 Post-modification recorded balance $ 23,110 2,203 9,927 10,325 157 498 TDRs that subsequently defaulted Number of loans 7 1 1 4 — 1 Recorded balance $ 2,556 1,947 78 529 — 2 The modifications for the TDRs that occurred during the years ended December 31, 2017 , 2016 and 2015 included one or a combination of the following: an extension of the maturity date, a reduction of the interest rate or a reduction in the principal amount. In addition to the TDRs that occurred during the period provided in the preceding tables, the Company had TDRs with pre-modification loan balances of $5,987,000 , $5,331,000 and $8,893,000 for the years ended December 31, 2017 , 2016 and 2015 , respectively, for which OREO was received in full or partial satisfaction of the loans. The majority of such TDRs were in commercial real estate for the years ended December 31, 2017 and 2015 and in residential real estate for the year ended December 31, 2016 . At December 31, 2017 and 2016 , the Company had $743,000 and $1,770,000 , respectively, of consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings are in process. At December 31, 2017 and 2016 , the Company had $893,000 and $2,699,000 , respectively, of OREO secured by residential real estate properties. There were $1,960,000 and $4,785,000 of additional unfunded commitments on TDRs outstanding at December 31, 2017 and 2016 , respectively. The amount of charge-offs on TDRs during 2017 , 2016 and 2015 was $2,984,000 , $557,000 and $1,310,000 , respectively.

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Premises and Equipment	Premises and Equipment Premises and equipment, net of accumulated depreciation, consist of the following: (Dollars in thousands) December 31, 2017 December 31, 2016 Land $ 31,370 29,648 Office buildings and construction in progress 182,592 173,886 Furniture, fixtures and equipment 83,177 84,559 Leasehold improvements 8,085 7,853 Accumulated depreciation (127,876 ) (119,748 ) Net premises and equipment $ 177,348 176,198 Depreciation expense for the years ended December 31, 2017 , 2016 , and 2015 was $14,758,000 , $15,294,000 , and $14,365,000 , respectively. The Company leases certain land, premises and equipment from third parties under operating and capital leases. Total rent expense for the years ended December 31, 2017 , 2016 , and 2015 was $3,629,000 , $3,255,000 , and $3,137,000 , respectively. Amortization of building capital lease assets is included in depreciation. The Company has entered into lease transactions with related parties. Rent expense with such related parties for the years ended December 31, 2017 , 2016 , and 2015 was $164,000 , $153,000 , and $150,000 , respectively. The total future minimum rental commitments required under operating and capital leases that have initial or remaining noncancelable lease terms in excess of one year at December 31, 2017 are as follows: (Dollars in thousands) Capital Leases Operating Leases Total Years ending December 31, 2018 $ 92 2,633 2,725 2019 92 2,502 2,594 2020 92 2,039 2,131 2021 11 1,593 1,604 2022 — 953 953 Thereafter — 5,541 5,541 Total minimum lease payments 287 15,261 15,548 Less: Amount representing interest 27 Present value of minimum lease payments 260 Less: Current portion of obligations under capital leases 79 Long-term portion of obligations under capital leases $ 181

Other Intangible Assets and Goo

Other Intangible Assets and Goodwill	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Other Intangible Assets and Goodwill	Other Intangible Assets and Goodwill The following table sets forth information regarding the Company’s core deposit intangibles: At or for the Years ended (Dollars in thousands) December 31, December 31, December 31, Gross carrying value $ 21,649 21,943 38,527 Accumulated amortization (7,465 ) (9,596 ) (23,972 ) Net carrying value $ 14,184 12,347 14,555 Aggregate amortization expense $ 2,494 2,970 2,964 Estimated amortization expense for the years ending December 31, 2018 $ 2,209 2019 2,100 2020 2,027 2021 1,952 2022 1,871 Core deposit intangibles increased $4,331,000 , $762,000 and $6,619,000 during 2017 , 2016 and 2015 , respectively, due to acquisitions. For additional information relating to acquisitions, see Note 22. The following schedule discloses the changes in the carrying value of goodwill: Years ended (Dollars in thousands) December 31, December 31, December 31, Net carrying value at beginning of period $ 147,053 140,638 129,706 Acquisitions and adjustments 30,758 6,415 10,932 Net carrying value at end of period $ 177,811 147,053 140,638 The Company’s first step in evaluating goodwill for possible impairment is a control premium analysis. The analysis first calculates the market capitalization and then adjusts such value for a control premium range which results in an implied fair value. The control premium range is determined based on historical control premiums for acquisitions that are comparable to the Company and is obtained from an independent third party. The calculated implied fair value is then compared to the book value to determine whether the Company needs to proceed to step two of the goodwill impairment assessment. The Company performed its annual goodwill impairment test during the third quarter of 2017 and determined the fair value of the aggregated reporting units exceeded the carrying value, such that the Company’s goodwill was not considered impaired. In recognition there were no events or circumstances that occurred during the fourth quarter of 2017 that would more-likely-than-not reduce the fair value of a reporting unit below its carrying value, the Company did not perform interim testing at December 31, 2017. Changes in the economic environment, operations of the aggregated reporting units, or other factors could result in the decline in the fair value of the aggregated reporting units which could result in a goodwill impairment in the future. Accumulated impairment charges were $40,159,000 as of December 31, 2017 and 2016 .

Variable Interest Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Variable Interest Entities	Variable Interest Entities A VIE is a partnership, limited liability company, trust or other legal entity that meets one of the following criteria: 1) the entity’s equity investment at risk is not sufficient to permit the entity to finance its activities without additional subordinated financial support from other parties; 2) the holders of the equity investment at risk, as a group, lack the characteristics of a controlling financial interest; and 3) the voting rights of some holders of the equity investment at risk are disproportionate to their obligation to absorb losses or receive returns, and substantially all of the activities are conducted on behalf of the holder of equity investment at risk with disproportionately few voting rights. A VIE must be consolidated by the Company if it is deemed to be the primary beneficiary, which is the party involved with the VIE that has both: 1) the power to direct the activities of the VIE that most significantly affect the VIE’s economic performance; and 2) the obligation to absorb the losses of the VIE that could potentially be significant to the VIE or the right to receive benefits from the VIE that could potentially be significant to the VIE. The Company’s VIEs are regularly monitored to determine if any reconsideration events have occurred that could cause the primary beneficiary status to change. A previously unconsolidated VIE is consolidated when the Company becomes the primary beneficiary. A previously consolidated VIE is deconsolidated when the Company ceases to be the primary beneficiary or the entity is no longer a VIE. Consolidated Variable Interest Entities The Company has equity investments in Certified Development Entities (“CDE”) which have received allocations of New Markets Tax Credits (“NMTC”). The NMTC program provides federal tax incentives to investors to make investments in distressed communities and promotes economic improvements through the development of successful businesses in these communities. The NMTC is available to investors over a seven -year period and is subject to recapture if certain events occur during such period. The maximum exposure to loss in the CDEs is the amount of equity invested and credit extended by the Company. However, the Company has credit protection in the form of indemnification agreements, guarantees, and collateral arrangements. The Company has evaluated the variable interests held by the Company in each CDE (NMTC) investment and determined the Company does not individually meet the characteristics of a primary beneficiary; however, the related-party group does meet the criteria as a group and substantially all of the activities of the CDEs either involve or are conducted on behalf of the Company. As a result, the Company is the primary beneficiary of the CDEs and their assets, liabilities, and results of operations are included in the Company’s consolidated financial statements. The primary activities of the CDEs are recognized in commercial loans interest income and other borrowed funds interest expense on the Company’s statements of operations and the federal income tax credit allocations from the investments are recognized in the Company’s statements of operations as a component of income tax expense. Such related cash flows are recognized in loans originated, principal collected on loans and change in other borrowed funds. The following table summarizes the carrying amounts of the consolidated VIEs’ assets and liabilities included in the Company’s statements of financial condition and are adjusted for intercompany eliminations. All assets presented can be used only to settle obligations of the consolidated VIEs and all liabilities presented consist of liabilities for which creditors and other beneficial interest holders therein have no recourse to the general credit of the Company. (Dollars in thousands) December 31, December 31, Assets Loans receivable $ 57,796 36,950 Accrued interest receivable 94 120 Other assets 15,885 10,024 Total assets $ 73,775 47,094 Liabilities Other borrowed funds $ 7,964 4,105 Accrued interest payable 1 2 Other liabilities 98 27 Total liabilities $ 8,063 4,134 Note 6. Variable Interest Entities (continued) Unconsolidated Variable Interest Entities The Company has equity investments in Low-Income Housing Tax Credit (“LIHTC”) partnerships with carrying values of $9,169,000 and $7,282,000 as of December 31, 2017 and 2016 , respectively. The LIHTCs are indirect federal subsidies to finance low-income housing and are used in connection with both newly constructed and renovated residential rental buildings. Once a project is placed in service, it is generally eligible for the tax credit for ten consecutive years. To continue generating the tax credit and to avoid tax credit recapture, a LIHTC building must satisfy specific low-income housing compliance rules for a full fifteen -year period. The maximum exposure to loss in the VIEs is the amount of equity invested and credit extended by the Company. However, the Company has credit protection in the form of indemnification agreements, guarantees, and collateral arrangements. The Company has evaluated the variable interests held by the Company in each LIHTC investment and determined that the Company does not have controlling financial interests in such investments, and is not the primary beneficiary. The Company reports the investments in the unconsolidated LIHTCs as other assets on the Company’s statements of financial condition. Total unfunded contingent commitments related to the Company’s LIHTC investments totaled $27,831,000 at December 31, 2017 , and the Company expects to fulfill these commitments during 2018 . There were no impairment losses on the Company’s LIHTC investments during the years ended December 31, 2017 , 2016 , and 2015 . The Company has elected to use the proportional amortization method, and more specifically the practical expedient method, for the amortization of all eligible LIHTC investments and amortization expense is recognized as a component of income tax expense. The following table summarizes the amortization expense and the amount of tax credits and other tax benefits recognized for qualified affordable housing project investments during the periods presented. Years ended (Dollars in thousands) December 31, 2017 December 31, 2016 December 31, Amortization expense $ 2,507 1,125 974 Tax credits and other tax benefits recognized 3,827 1,515 1,552 The Company also owns the following trust subsidiaries, each of which issued trust preferred securities as Tier 1 capital instruments: Glacier Capital Trust II, Glacier Capital Trust III, Glacier Capital Trust IV, Citizens (ID) Statutory Trust I, Bank of the San Juans Bancorporation Trust I, First Company Statutory Trust 2001, and First Company Statutory Trust 2003. The trust subsidiaries have no assets, operations, revenues or cash flows other than those related to the issuance, administration and repayment of the securities held by third parties. The trust subsidiaries are not included in the Company’s consolidated financial statements because the sole asset of each trust subsidiary is a receivable from the Company, even though the Company owns all of the voting equity shares of the trust subsidiaries, has fully guaranteed the obligations of the trust subsidiaries and may have the right to redeem the third party securities under certain circumstances. The Company reports the trust preferred securities issued to the trust subsidiaries as subordinated debentures on the Company’s statements of financial condition. For additional information on the Company’s investments in trust subsidiaries, see Note 9.

Deposits

Deposits	12 Months Ended
	Dec. 31, 2017
Deposits [Abstract]
Deposits	Deposits Time deposits that meet or exceed the Federal Deposit Insurance Corporation Insurance (“FDIC”) limit of $250,000 at December 31, 2017 and 2016 were $193,962,000 and $254,611,000 , respectively. The scheduled maturities of time deposits are as follows: (Dollars in thousands) Amount Years ending December 31, 2018 $ 557,693 2019 120,657 2020 65,284 2021 45,409 2022 27,974 Thereafter 242 $ 817,259 The Company reclassified $4,402,000 and $3,618,000 of overdraft demand deposits to loans as of December 31, 2017 and 2016 , respectively. The Company has entered into deposit transactions with its executive officers, directors and their affiliates. The aggregate amount of deposits with such related parties at December 31, 2017 and 2016 was $25,641,000 and $27,977,000 , respectively.

Borrowings

Borrowings	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Borrowings	Borrowings The Company’s repurchase agreements totaled $362,573,000 and $473,650,000 at December 31, 2017 and 2016 , respectively, and are secured by investment securities with carrying values of $475,601,000 and $472,239,000 , respectively. Securities are pledged to customers at the time of the transaction in an amount at least equal to the outstanding balance and are held in custody accounts by third parties. The fair value of collateral is continually monitored and additional collateral is provided as deemed appropriate. The following tables summarize the carrying value of the Company’s repurchase agreements by remaining contractual maturity and category of collateral: December 31, 2017 Remaining Contractual Maturity of the Agreements (Dollars in thousands) Overnight and Continuous Up to 30 Days Total Residential mortgage-backed securities $ 360,751 — 360,751 Commercial mortgage-backed securities 1,822 — 1,822 Total $ 362,573 — 362,573 December 31, 2016 Remaining Contractual Maturity of the Agreements (Dollars in thousands) Overnight and Continuous Up to 30 Days Total Residential mortgage-backed securities $ 471,706 643 472,349 Commercial mortgage-backed securities 1,301 — 1,301 Total $ 473,007 643 473,650 Note 8. Borrowings (continued) The Company’s FHLB advances bear a fixed rate of interest and are subject to restrictions or penalties in the event of prepayment. The advances are collateralized by specifically pledged loans and investment securities, FHLB stock owned by the Company, and a blanket assignment of the unpledged qualifying loans and investments. During the year ended December 31, 2017 , the Company modified the majority of its long-term FHLB advances, including prepaying higher cost advances, to strategically manage its asset size. The scheduled maturities of FHLB advances consist of the following: December 31, 2017 December 31, 2016 (Dollars in thousands) Amount Weighted Rate Amount Weighted Rate Maturing within one year $ 200,869 1.64 % $ 41,099 0.84 % Maturing one year through two years 887 2.05 % 70,983 1.42 % Maturing two years through three years 1,651 3.58 % 927 2.16 % Maturing three years through four years 148,721 2.69 % 1,728 3.66 % Maturing four years through five years 945 5.25 % 135,000 3.08 % Thereafter 922 5.42 % 2,012 5.33 % Total $ 353,995 2.11 % $ 251,749 2.27 % The Company’s other borrowings consisted of capital lease obligations and other debt obligations through consolidation of certain VIEs. At December 31, 2017 , the Company had $230,000,000 in unsecured lines of credit which are typically renewed on an annual basis with various correspondent entities.

Subordinated Debentures

Subordinated Debentures	12 Months Ended
	Dec. 31, 2017
Debt Instruments [Abstract]
Subordinated Debentures	Subordinated Debentures Trust preferred securities were issued by the Company’s trust subsidiaries, the common stock of which is wholly-owned by the Company, in conjunction with the Company issuing subordinated debentures to the trust subsidiaries. The terms of the subordinated debentures are the same as the terms of the trust preferred securities. The Company guaranteed the payment of distributions and payments for redemption or liquidation of the trust preferred securities to the extent of funds held by the trust subsidiaries. The obligations of the Company under the subordinated debentures together with the guarantee and other back-up obligations, in the aggregate, constitute a full and unconditional guarantee by the Company of the obligations of all trusts under the trust preferred securities. The trust preferred securities are subject to mandatory redemption upon repayment of the subordinated debentures at their stated maturity date or the earlier redemption in an amount equal to their liquidation amount plus accumulated and unpaid distributions to the date of redemption. Interest distributions are payable quarterly. The Company may defer the payment of interest at any time for a period not exceeding 20 consecutive quarters provided that the deferral period does not extend past the stated maturity. During any such deferral period, distributions on the trust preferred securities will also be deferred and the Company’s ability to pay dividends on its common shares will be restricted. Subject to prior approval by the FRB, the trust preferred securities may be redeemed at par prior to maturity at the Company’s option on or after the redemption date. All of the Company’s trust preferred securities have reached the redemption date and could be redeemed at the Company’s option. The trust preferred securities may also be redeemed at any time in whole (but not in part) for the Trusts in the event of unfavorable changes in laws or regulations that result in 1) subsidiary trusts becoming subject to federal income tax on income received on the subordinated debentures; 2) interest payable by the Company on the subordinated debentures becoming non-deductible for federal tax purposes; 3) the requirement for the trusts to register under the Investment Company Act of 1940, as amended; or 4) loss of the ability to treat the trust preferred securities as Tier 1 capital under the FRB capital adequacy guidelines. For regulatory capital purposes, the FRB has allowed bank holding companies to continue to include trust preferred securities in Tier 1 capital up to a certain limit. Provisions of the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010 (“Dodd-Frank Act”) require the FRB to exclude trust preferred securities from Tier 1 capital, but a permanent grandfather provision applicable to the Company permits bank holding companies with consolidated assets of less than $15 billion to continue counting existing trust preferred securities as Tier 1 capital until they mature, even after the Company’s total assets exceed $15 billion . All of the Company’s trust preferred securities qualified as Tier 1 capital instruments at December 31, 2017 . For additional information on regulatory capital, see Note 11. Note 9. Subordinated Debentures (continued) The terms of the subordinated debentures, arranged by maturity date, are reflected in the table below. The amounts include fair value adjustments from acquisitions. December 31, 2017 Variable Rate Structure Maturity Date (Dollars in thousands) Balance Rate First Company Statutory Trust 2001 $ 3,269 4.680 % 3 month LIBOR plus 3.30% 07/31/2031 First Company Statutory Trust 2003 2,407 4.925 % 3 month LIBOR plus 3.25% 03/26/2033 Glacier Capital Trust II 46,393 4.109 % 3 month LIBOR plus 2.75% 04/07/2034 Citizens (ID) Statutory Trust I 5,155 4.250 % 3 month LIBOR plus 2.65% 06/17/2034 Glacier Capital Trust III 36,083 2.649 % 3 month LIBOR plus 1.29% 04/07/2036 Glacier Capital Trust IV 30,928 3.158 % 3 month LIBOR plus 1.57% 09/15/2036 Bank of the San Juans Bancorporation Trust I 1,900 3.301 % 3 month LIBOR plus 1.82% 03/01/2037 $ 126,135

Derivatives and Hedging Activit

Derivatives and Hedging Activities	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedging Activities	Derivatives and Hedging Activities The Company is exposed to certain risk relating to its ongoing business operations. The primary risk managed by using derivative instruments is interest rate risk. Interest rate swaps are entered into to manage interest rate risk associated with the Company’s forecasted variable rate borrowings. The Company recognizes interest rate swaps as either assets or liabilities at fair value in the statements of financial condition, after taking into account the effects of bilateral collateral and master netting agreements. These agreements allow the Company to settle all interest rate swap agreements held with a single counterparty on a net basis, and to offset net interest rate swap derivative positions with related collateral, where applicable. The interest rate swaps on variable rate borrowings were designated as cash flow hedges and were over-the-counter contracts. The contracts were entered into by the Company with a single counterparty, and the specific terms and conditions were negotiated, including forecasted notional amounts, interest rates and maturity dates. The Company is exposed to credit-related losses in the event of nonperformance by the counterparty to the agreements. The Company controls the counterparty credit risk by maintaining bilateral collateral agreements and through monitoring policy and procedures. The Company only conducts business with primary dealers and believes that the credit risk inherent in these contracts was not significant. The Company’s interest rate swap derivative financial instruments as of December 31, 2017 are as follows: (Dollars in thousands) Forecasted Notional Amount Variable Interest Rate 1 Fixed Interest Rate 1 Payment Term Interest rate swap $ 160,000 3 month LIBOR 3.378 % Oct. 21, 2014 - Oct. 21, 2021 Interest rate swap 100,000 3 month LIBOR 2.498 % Nov. 30, 2015 - Nov. 30, 2022 ______________________________ 1 The Company pays the fixed interest rate and the counterparty pays the Company the variable interest rate. The hedging strategy converts the LIBOR-based variable interest rate on borrowings to a fixed interest rate, thereby protecting the Company from interest rate variability. Note 10. Derivatives and Hedging Activities (continued) The interest rate swaps with the $160,000,000 and $100,000,000 notional amounts began their payment terms in October 2014 and November 2015, respectively. The Company designated wholesale deposits and FHLB advances as the cash flow hedge and these hedged items were determined to be fully effective during current and prior years. As such, no amount of ineffectiveness has been included in the Company’s statements of operations for the years ended December 31, 2017 , 2016 and 2015 . Therefore, the aggregate fair value of the interest rate swaps was recorded in other liabilities with changes recorded in OCI. The Company expects the hedges to remain highly effective during the remaining terms of the interest rate swaps. Interest expense recorded on the interest rate swaps totaled $8,013,000 , $8,035,000 and $5,695,000 during 2017 , 2016 and 2015 , respectively, and is reported as a component of interest expense on deposits and FHLB advances. Unless the interest rate swaps are terminated during the next year, the Company expects $4,228,000 of the unrealized loss reported in OCI at December 31, 2017 to be reclassified to interest expense during the next twelve months. The following table presents the pre-tax gains or losses recorded in OCI and the Company’s statements of operations relating to the interest rate swap derivative financial instruments: Years ended (Dollars in thousands) December 31, December 31, December 31, Interest rate swaps Amount of gain (loss) recognized in OCI (effective portion) $ 444 (1,643 ) (7,857 ) Amount of loss reclassified from OCI to interest expense (4,892 ) (6,417 ) (5,025 ) Amount of loss recognized in other non-interest expense (ineffective portion) — — — The following table discloses the offsetting of financial liabilities and interest rate swap derivative liabilities. There were no interest rate swap derivative assets at the dates presented. December 31, 2017 December 31, 2016 (Dollars in thousands) Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Statements of Financial Position Net Amounts of Liabilities Presented in the Statements of Financial Position Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Statements of Financial Position Net Amounts of Liabilities Presented in the Statements of Financial Position Interest rate swaps $ 9,389 — 9,389 14,725 — 14,725 Pursuant to the interest rate swap agreements, the Company pledged collateral to the counterparty in the form of investment securities totaling $23,692,000 at December 31, 2017 . There was $0 collateral pledged from the counterparty to the Company as of December 31, 2017 . There is the possibility that the Company may need to pledge additional collateral in the future if there were declines in the fair value of the interest rate swap derivative financial instruments versus the collateral pledged.

Regulatory Capital

Regulatory Capital	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Regulatory Capital	Regulatory Capital The Federal Reserve has adopted capital adequacy guidelines that are used to assess the adequacy of capital in supervising a bank holding company. The federal banking agencies implemented final rules (“Final Rules”) to establish a new comprehensive regulatory capital framework with a phase-in period beginning on January 1, 2015 and ending on January 1, 2019. The Final Rules implemented certain regulatory amendments based on the recommendation of the Basel Committee on Banking Supervision and certain requirements of the Dodd-Frank Act and substantially amended the regulatory risk-based capital rules applicable to the Company. The Final Rules require the Company to hold a conservation buffer designed to absorb losses during periods of economic stress. The capital conservation buffer for 2017 is 1.25 percent . The Company has elected to opt-out of the requirement to include most components of AOCI. As of December 31, 2017 , management believes the Company and Bank meet all capital adequacy requirements to which they are subject. Prompt corrective action regulations provide the following classifications: well capitalized, adequately capitalized, undercapitalized, significantly undercapitalized and critically undercapitalized. If undercapitalized, capital distributions (including payment of a dividend) are generally restricted, as is paying management fees to its bank holding company. Failure to meet minimum capital requirements set forth in the table below can initiate certain mandatory and possible additional discretionary actions by regulators that, if undertaken, could have a direct material effect on the Company’s and Bank’s financial condition. The Company’s and Bank’s capital amounts and classification are also subject to qualitative judgments by the regulators about components, risk weightings and other factors. At December 31, 2017 and 2016 , the most recent regulatory notifications categorized the Company and Bank as well capitalized under the regulatory framework for prompt corrective action. To be well capitalized, the Bank must maintain minimum total capital, Tier 1 capital, Common Tier 1 capital and Tier 1 Leverage ratios as set forth in the table below. There are no conditions or events since December 31, 2017 that management believes have changed the Company’s or Bank’s risk-based capital category. Current guidance from the Federal Reserve provides, among other things, that dividends per share on the Company’s common stock generally should not exceed earnings per share, measured over the previous four fiscal quarters. The Bank is also subject to Montana state law and cannot declare a dividend greater than the previous two years’ net earnings without providing notice to the state. The following tables illustrate the FRB’s adequacy guidelines and the Company’s and the Bank’s compliance with those guidelines: December 31, 2017 Actual Required for Capital Adequacy Purposes To Be Well Capitalized Under Prompt Corrective Action Regulations (Dollars in thousands) Amount Ratio Amount Ratio Amount Ratio Total capital (to risk-weighted assets) Consolidated $ 1,232,089 15.64 % $ 630,109 8.00 % N/A N/A Glacier Bank 1,182,509 15.04 % 628,823 8.00 % $ 786,029 10.00 % Tier 1 capital (to risk-weighted assets) Consolidated 1,133,125 14.39 % 472,582 6.00 % N/A N/A Glacier Bank 1,083,744 13.79 % 471,617 6.00 % 628,823 8.00 % Common Equity Tier 1 (to risk-weighted assets) Consolidated 1,009,276 12.81 % 354,437 4.50 % N/A N/A Glacier Bank 1,083,744 13.79 % 353,713 4.50 % 510,919 6.50 % Tier 1 capital (to average assets) Consolidated 1,133,125 11.90 % 380,770 4.00 % N/A N/A Glacier Bank 1,083,744 11.47 % 377,809 4.00 % 472,261 5.00 % Note 11. Regulatory Capital (continued) December 31, 2016 Actual Required for Capital Adequacy Purposes To Be Well Capitalized (Dollars in thousands) Amount Ratio Amount Ratio Amount Ratio Total capital (to risk-weighted assets) Consolidated $ 1,179,673 16.38 % $ 576,092 8.00 % N/A N/A Glacier Bank 1,131,949 15.76 % 574,658 8.00 % $ 718,323 10.00 % Tier 1 capital (to risk-weighted assets) Consolidated 1,089,142 15.12 % 432,069 6.00 % N/A N/A Glacier Bank 1,041,640 14.50 % 430,994 6.00 % 574,658 8.00 % Common Equity Tier 1 (to risk-weighted assets) Consolidated 966,701 13.42 % 324,052 4.50 % N/A N/A Glacier Bank 1,041,640 14.50 % 323,245 4.50 % 466,910 6.50 % Tier 1 capital (to average assets) Consolidated 1,089,142 11.90 % 365,994 4.00 % N/A N/A Glacier Bank 1,041,640 11.45 % 363,945 4.00 % 454,932 5.00 % ______________________________ N/A - Not applicable

Stock-based Compensation Plan

Stock-based Compensation Plan	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based Compensation Plan	Stock-based Compensation Plan The Company has two stock-based compensation plans in effect at December 31, 2017 . The 2005 Stock Incentive Plan expired in April 2015, but still has non-vested restricted stock awards at December 31, 2017 . The 2015 Stock Incentive Plan provides incentives and awards to select employees and directors of the Company and permits the granting of stock options, share appreciation rights, restricted shares, restricted share units, unrestricted shares and performance awards. At December 31, 2017 , the number of shares available to award to employees and directors under the 2015 Stock Incentive Plan was 2,249,767 . Restricted Stock Awards The Company has awarded restricted stock to select employees and directors under the 2005 and 2015 Stock Incentive Plans. Common stock is issued as vesting restrictions lapse, which may be immediately or according to the terms of a vesting schedule. Restricted stock awards may not be sold, pledged or otherwise transferred until restrictions have lapsed. Under the 2005 Stock Incentive Plan, the recipient does not have the right to vote until the restricted stock award has vested but does have the right to receive dividends. Under the 2015 Stock Incentive Plan, the recipient does not have the right to vote or to receive dividends until the restricted stock award has vested. The fair value of the restricted stock awarded is the closing price of the Company’s common stock on the award date. Compensation expense related to restricted stock awards for the years ended December 31, 2017 , 2016 and 2015 was $3,764,000 , $2,870,000 and $2,470,000 , respectively, and the recognized income tax benefit related to this expense was $1,452,000 , $1,112,000 and $957,000 . As of December 31, 2017 , total unrecognized compensation expense of $3,288,000 related to restricted stock awards is expected to be recognized over a weighted-average period of 1.8 years . The fair value of restricted stock awards that vested during the years ended December 31, 2017 , 2016 and 2015 was $3,746,000 , $2,624,000 and $1,761,000 , respectively, and the income tax benefit related to these awards was $1,998,000 , $1,053,000 and $795,000 , respectively. Upon vesting of restricted stock awards, the shares are issued from the Company’s authorized stock balance. Note 12. Stock-based Compensation Plan (continued) The following table summarizes the restricted stock award activity for the year ended December 31, 2017 : Restricted Stock Weighted- Average Grant Date Fair Value Non-vested at December 31, 2016 222,732 $ 24.46 Granted 104,836 36.59 Vested (141,864 ) 26.41 Forfeited (2,526 ) 29.07 Non-vested at December 31, 2017 183,178 29.84 The average remaining contractual term on non-vested restricted stock awards at December 31, 2017 is 0.8 years . The aggregate intrinsic value of the non-vested restricted stock awards at December 31, 2017 was $7,215,000 .

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Employee Benefit Plans	Employee Benefit Plans The Company provides its qualified employees with a comprehensive benefit program, including health, dental and vision insurance, life and accident insurance, short- and long-term disability coverage, vacation and sick leave, 401(k) plan, profit sharing plan, stock-based compensation plan, deferred compensation plans, and supplemental executive retirement plan. The Company has elected to self-insure certain costs related to employee health, dental and vision benefit programs. Costs resulting from noninsured losses are expensed as incurred. The Company has purchased insurance that limits its exposure on an individual claim basis for the employee health benefit programs. 401(k) Plan and Profit Sharing Plan The Company’s 401(k) plan and profit sharing plan have safe harbor and employer discretionary components. To be considered eligible for the 401(k) and safe harbor components of the profit sharing plan, an employee must be 21 years of age and employed for three full months. Employees are eligible to participate in the 401(k) plan the first day of the month once they have met the eligibility requirements. To be considered eligible for the employer discretionary contribution of the profit sharing plan, an employee must be 21 years of age, worked one full calendar quarter, worked 501 hours in the plan year and be employed as of the last day of the plan year. Participants are at all times fully vested in all contributions. The profit sharing plan contributions consists of a 3 percent non-elective safe harbor contribution fully funded by the Company and an employer discretionary contribution. The employer discretionary contribution depends on the Company’s profitability. The total profit sharing plan expense for the years ended December 31, 2017 , 2016 , and 2015 was $10,100,000 , $9,041,000 and $8,017,000 respectively. The 401(k) plan allows eligible employees under the age of 50 to contribute up to 60 percent , and those 50 and older to contribute up to 100 percent of their eligible annual compensation up to the limit set annually by the Internal Revenue Service (“IRS”). The Company matches an amount equal to 50 percent of the first 6 percent of an employee’s contribution. The Company’s contribution to the 401(k) for the years ended December 31, 2017 , 2016 and 2015 was $3,224,000 , $2,946,000 , and $2,629,000 , respectively. Deferred Compensation Plans The Company has non-funded deferred compensation plans for directors, senior officers and certain nonemployee service providers. The plans provide for participants’ elective deferral of cash payments of up to 50 percent of a participants’ salary and 100 percent of bonuses and directors fees. The total amount deferred for the plans was $739,000 , $967,000 , and $720,000 , for the years ending December 31, 2017 , 2016 , and 2015 , respectively. The participant receives an earnings credit at a rate equal to 50 percent of the Company’s return on average equity. The total earnings for the years ended December 31, 2017 , 2016 , and 2015 for the plans was $481,000 , $431,000 and $386,000 , respectively. In connection with several acquisitions, the Company assumed the obligations of deferred compensation plans for certain key employees. As of December 31, 2017 and 2016 , the liability related to the obligations was $11,275,000 and $11,273,000 , respectively, and was included in other liabilities. The total earnings for the years ended December 31, 2017 , 2016 , and 2015 for the acquired plans was insignificant. Note 13. Employee Benefit Plans (continued) Supplemental Executive Retirement Plan The Company has a Supplemental Executive Retirement Plan (“SERP”) which is intended to supplement payments due to participants upon retirement under the Company’s other qualified plans. The Company credits the participant’s account on an annual basis for an amount equal to employer contributions that would have otherwise been allocated to the participant’s account under the tax-qualified plans were it not for limitations imposed by the IRS or the participation in the non-funded deferred compensation plan. Eligible employees include participants of the non-funded deferred compensation plan and employees whose benefits were limited as a result of IRS regulations. The Company’s required contribution to the SERP for the years ended December 31, 2017 , 2016 and 2015 was $287,000 , $299,000 , and $224,000 , respectively. The participant receives an earnings credit at a rate equal to 50 percent of the Company’s return on average equity. The total earnings for the years ended December 31, 2017 , 2016 , and 2015 for this plan was $105,000 , $85,000 , and $69,000 , respectively.

Other Expenses

Other Expenses	12 Months Ended
	Dec. 31, 2017
Other Expenses [Abstract]
Other Expenses	Other Expenses Other expenses consists of the following: Years ended (Dollars in thousands) December 31, December 31, December 31, Debit card expenses $ 7,189 8,462 6,153 Consulting and outside services 5,331 5,683 3,845 Employee expenses 4,160 3,573 2,425 Telephone 3,891 3,828 3,318 VIE amortization and other expenses 3,109 2,702 4,528 Loan expenses 3,080 3,611 2,824 Postage 2,684 2,785 3,716 Printing and supplies 2,661 2,800 3,529 Mergers and acquisition expenses 2,130 1,732 2,459 Business development 1,929 1,847 1,526 Accounting and audit fees 1,848 1,613 1,331 Checking and operating expenses 1,760 2,942 3,553 ATM expenses 1,720 880 1,082 Legal fees 1,106 1,027 866 Other 4,447 4,085 3,892 Total other expenses $ 47,045 47,570 45,047

Federal and State Income Taxes

Federal and State Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Federal and State Income Taxes	Federal and State Income Taxes The Tax Act was enacted on December 22, 2017 and resulted in a decrease in the federal marginal tax rate from 35 percent to 21 percent beginning in 2018. As a result of the Tax Act, the Company incurred a one-time tax expense adjustment of $19,699,000 during 2 017 due to the Company’s revaluation of its net deferred tax assets. This adjustment is reflected in the following tables. The following table is a summary of consolidated income tax expense: Years ended (Dollars in thousands) December 31, December 31, December 31, Current Federal $ 29,555 30,461 28,705 State 9,183 9,283 9,374 Total current income tax expense 38,738 39,744 38,079 Deferred 1 Federal 22,246 (70 ) (3,451 ) State 3,641 (12 ) (629 ) Total deferred income tax expense (benefit) 25,887 (82 ) (4,080 ) Total income tax expense $ 64,625 39,662 33,999 ______________________________ 1 Includes tax benefit of operating loss carryforwards of $644,000 , $571,000 and $391,000 for the years ended December 31, 2017 , 2016 , and 2015 , respectively. Combined federal and state income tax expense differs from that computed at the federal statutory corporate tax rate as follows: Years ended December 31, December 31, December 31, Federal statutory rate 35.0 % 35.0 % 35.0 % State taxes, net of federal income tax benefit 4.6 % 3.8 % 3.7 % Tax rate change 10.9 % — % — % Tax-exempt interest income (10.5 )% (12.2 )% (12.6 )% Tax credits (3.2 )% (2.1 )% (3.0 )% Other, net (1.1 )% 0.2 % (0.5 )% Effective tax rate 35.7 % 24.7 % 22.6 % Note 15. Federal and State Income Taxes (continued) The tax effect of temporary differences which give rise to a significant portion of deferred tax assets and deferred tax liabilities are as follows: (Dollars in thousands) December 31, December 31, Deferred tax assets Allowance for loan and lease losses $ 32,890 50,172 Deferred compensation 5,640 8,320 Other real estate owned 5,126 8,309 Acquisition fair market value adjustments 4,139 4,763 Net operating loss carryforwards 2,841 4,737 Employee benefits 2,615 3,927 Interest rate swap agreements 2,379 5,705 Other 3,673 5,569 Total gross deferred tax assets 59,303 91,502 Deferred tax liabilities Deferred loan costs (5,854 ) (8,061 ) Intangibles (4,161 ) (5,477 ) Depreciation of premises and equipment (2,863 ) (3,111 ) FHLB stock dividends (2,602 ) (3,976 ) Available-for-sale securities (1,707 ) (1,036 ) Debt modification costs (1,591 ) — Other (2,181 ) (2,720 ) Total gross deferred tax liabilities (20,959 ) (24,381 ) Net deferred tax asset $ 38,344 67,121 The Company has federal net operating loss carryforwards of $10,635,000 expiring between 2030 and 2035 . The Company has Colorado net operating loss carryforwards of $13,987,000 expiring between 2031 and 2032 . The net operating loss carryforwards originated from bank acquisitions. The Company has federal tax credit carryforwards with no expiration dates of $411,000 . The Company and the Bank file consolidated income tax returns in the following jurisdictions: federal, Montana, Idaho, Utah, Colorado and Arizona. Although the Bank has operations in Wyoming and Washington, neither Wyoming nor Washington imposes a corporate-level income tax. All required income tax returns have been timely filed. The following schedule summarizes the years that remain subject to examination as of December 31, 2017 : Years ended December 31, Federal 2013, 2014, 2015 and 2016 Montana 2014, 2015 and 2016 Idaho 2014, 2015 and 2016 Utah 2014, 2015 and 2016 Colorado 2013, 2014, 2015 and 2016 Arizona 2013, 2014, 2015 and 2016 Note 15. Federal and State Income Taxes (continued) The Company had no unrecognized income tax benefits as of December 31, 2017 and 2016 . The Company recognizes interest related to unrecognized income tax benefits in interest expense and penalties are recognized in other expense. Interest expense and penalties recognized with respect to income tax liabilities for the years ended December 31, 2017 , 2016 , and 2015 was not significant. The Company had no accrued liabilities for the payment of interest or penalties at December 31, 2017 and 2016 . The Company has assessed the need for a valuation allowance and determined that a valuation allowance was not necessary at December 31, 2017 and 2016 . The Company believes that it is more-likely-than-not that the Company’s deferred tax assets will be realizable by offsetting future taxable income from reversing taxable temporary differences and anticipated future taxable income (exclusive of reversing temporary differences). In its assessment, the Company considered its strong earnings history, no history of income tax credit carryforwards expiring unused, and no future net operating losses (for tax purposes) are expected.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) The following table illustrates the activity within accumulated other comprehensive income (loss) by component, net of tax: (Dollars in thousands) Gains on Available-For-Sale Securities Losses on Derivatives Used for Cash Flow Hedges Total Balance at December 31, 2014 $ 27,945 (10,201 ) 17,744 Other comprehensive loss before reclassifications (13,968 ) (4,823 ) (18,791 ) Reclassification adjustments for (losses) gains included in net income (42 ) 3,078 3,036 Net current period other comprehensive loss (14,010 ) (1,745 ) (15,755 ) Balance at December 31, 2015 $ 13,935 (11,946 ) 1,989 Other comprehensive loss before reclassifications (13,113 ) (1,006 ) (14,119 ) Reclassification adjustments for gains included in net income 817 3,931 4,748 Net current period other comprehensive (loss) income (12,296 ) 2,925 (9,371 ) Balance at December 31, 2016 $ 1,639 (9,021 ) (7,382 ) Other comprehensive income before reclassifications 2,110 248 2,358 Reclassification adjustments for gains included in net income 391 3,005 3,396 Reclassifications from accumulated other comprehensive income (loss) to retained earnings 1 891 (1,242 ) (351 ) Net current period other comprehensive income 3,392 2,011 5,403 Balance at December 31, 2017 $ 5,031 (7,010 ) (1,979 ) ______________________________ 1 Reclassifications were due to the one-time revaluation of the deferred tax assets and deferred tax liabilities as a result of the Tax Act. For additional information relating to this reclassification, see Note 1.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share Basic earnings per share is computed by dividing net income by the weighted-average number of shares of common stock outstanding during the period presented. Diluted earnings per share is computed by including the net increase in shares as if dilutive outstanding restricted stock awards were vested, using the treasury stock method. Basic and diluted earnings per share has been computed based on the following: Years ended (Dollars in thousands, except per share data) December 31, December 31, December 31, Net income available to common stockholders, basic and diluted $ 116,377 121,131 116,127 Average outstanding shares - basic 77,537,664 76,278,463 75,542,455 Add: dilutive restricted stock awards 69,941 63,373 53,126 Average outstanding shares - diluted 77,607,605 76,341,836 75,595,581 Basic earnings per share $ 1.50 1.59 1.54 Diluted earnings per share $ 1.50 1.59 1.54 There were no restricted stock awards excluded from the diluted average outstanding share calculation for the years ended December 31, 2017 , 2016 , and 2015 . Anti-dilution occurs when the unrecognized compensation cost per share of a restricted stock award exceeds the market price of the Company’s stock.

Parent Holding Company Informat

Parent Holding Company Information (Condensed)	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Parent Holding Company Information (Condensed)	Parent Holding Company Information (Condensed) The following condensed financial information was the unconsolidated information for the parent holding company: Condensed Statements of Financial Condition (Dollars in thousands) December 31, December 31, Assets Cash on hand and in banks $ 9,304 5,906 Interest bearing cash deposits 38,420 57,700 Cash and cash equivalents 47,724 63,606 Investment securities, available-for-sale — 36 Other assets 8,871 10,764 Investment in subsidiaries 1,281,392 1,201,667 Total assets $ 1,337,987 1,276,073 Liabilities and Stockholders’ Equity Dividends payable $ 265 23,137 Subordinated debentures 126,135 125,991 Other liabilities 12,530 10,076 Total liabilities 138,930 159,204 Common stock 780 765 Paid-in capital 797,997 749,107 Retained earnings 402,259 374,379 Accumulated other comprehensive loss (1,979 ) (7,382 ) Total stockholders’ equity 1,199,057 1,116,869 Total liabilities and stockholders’ equity $ 1,337,987 1,276,073 Note 18. Parent Holding Company Information (Condensed) (continued) Condensed Statements of Operations and Comprehensive Income Years ended (Dollars in thousands) December 31, December 31, December 31, Income Dividends from subsidiaries $ 119,000 108,350 109,000 Gain on sale of investments 3 — — Intercompany charges for services 14,299 12,248 10,562 Other income 225 311 196 Total income 133,527 120,909 119,758 Expenses Compensation and employee benefits 17,864 15,665 13,205 Other operating expenses 10,425 7,701 7,313 Total expenses 28,289 23,366 20,518 Income before income tax benefit and equity in undistributed net income of subsidiaries 105,238 97,543 99,240 Income tax benefit 2,983 4,040 3,105 Income before equity in undistributed net income of subsidiaries 108,221 101,583 102,345 Equity in undistributed net income of subsidiaries 8,156 19,548 13,782 Net Income $ 116,377 121,131 116,127 Comprehensive Income $ 122,131 111,760 100,372 Condensed Statements of Cash Flows Years ended (Dollars in thousands) December 31, December 31, December 31, Operating Activities Net income $ 116,377 121,131 116,127 Adjustments to reconcile net income to net cash provided by operating activities: Subsidiary income in excess of dividends distributed (8,156 ) (19,548 ) (13,782 ) Amortization of purchase accounting adjustments 143 143 143 Gain on sale of investments (3 ) — — Stock-based compensation, net of tax benefits 1,460 804 695 Net change in other assets and other liabilities 5,051 (297 ) 118 Net cash provided by operating activities 114,872 102,233 103,301 Investing Activities Sales of available-for-sale securities 27 — — Net (increase) decrease of premises and equipment (79 ) 771 (1,405 ) Proceeds from sale of non-marketable equity securities 114 55 22 Equity contributions to subsidiaries (17,565 ) (3,475 ) (28,457 ) Net cash used in by investing activities (17,503 ) (2,649 ) (29,840 ) Financing Activities Cash dividends paid (111,720 ) (84,040 ) (79,456 ) Tax withholding payments for stock-based compensation (1,531 ) (600 ) (489 ) Net cash used in financing activities (113,251 ) (84,640 ) (79,945 ) Net (decrease) increase in cash and cash equivalents (15,882 ) 14,944 (6,484 ) Cash and cash equivalents at beginning of year 63,606 48,662 55,146 Cash and cash equivalents at end of year $ 47,724 63,606 48,662

Unaudited Quarterly Financial D

Unaudited Quarterly Financial Data (Condensed)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Unaudited Quarterly Financial Data (Condensed)	Unaudited Quarterly Financial Data (Condensed) Summarized unaudited quarterly financial data is as follows: Quarters ended 2017 (Dollars in thousands, except per share data) March 31 June 30 September 30 December 31 Interest income $ 87,628 94,032 96,464 96,898 Interest expense 7,366 7,774 7,652 7,072 Net interest income 80,262 86,258 88,812 89,826 Provision for loan losses 1,598 3,013 3,327 2,886 Net interest income after provision for loan losses 78,664 83,245 85,485 86,940 Non-interest income 25,689 27,656 31,185 27,709 Non-interest expense 63,344 65,309 68,552 68,366 Income before income taxes 41,009 45,592 48,118 46,283 Federal and state income tax expense 9,754 11,905 11,639 31,327 Net income $ 31,255 33,687 36,479 14,956 Basic earnings per share $ 0.41 0.43 0.47 0.19 Diluted earnings per share $ 0.41 0.43 0.47 0.19 Quarters ended 2016 (Dollars in thousands, except per share data) March 31 June 30 September 30 December 31 Interest income $ 84,381 86,069 85,944 87,759 Interest expense 7,675 7,424 7,318 7,214 Net interest income 76,706 78,645 78,626 80,545 Provision for loan losses 568 — 626 1,139 Net interest income after provision for loan losses 76,138 78,645 78,000 79,406 Non-interest income 24,252 26,759 28,293 28,014 Non-interest expense 62,356 64,461 65,180 66,717 Income before income taxes 38,034 40,943 41,113 40,703 Federal and state income tax expense 9,352 10,492 10,156 9,662 Net income $ 28,682 30,451 30,957 31,041 Basic earnings per share $ 0.38 0.40 0.40 0.41 Diluted earnings per share $ 0.38 0.40 0.40 0.41

Fair Value of Assets and Liabil

Fair Value of Assets and Liabilities	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value of Assets and Liabilities	Fair Value of Assets and Liabilities Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. There is a fair value hierarchy which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The three levels of inputs that may be used to measure fair value are as follows: Level 1 Quoted prices in active markets for identical assets or liabilities Level 2 Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities Level 3 Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities Transfers in and out of Level 1 (quoted prices in active markets), Level 2 (significant other observable inputs) and Level 3 (significant unobservable inputs) are recognized on the actual transfer date. There were no transfers between fair value hierarchy levels during the years ended December 31, 2017 and 2016 . Recurring Measurements The following is a description of the inputs and valuation methodologies used for assets and liabilities measured at fair value on a recurring basis, as well as the general classification of such assets and liabilities pursuant to the valuation hierarchy. There have been no significant changes in the valuation techniques during the period ended December 31, 2017 . Investment securities, available-for-sale: fair value for available-for-sale securities is estimated by obtaining quoted market prices for identical assets, where available. If such prices are not available, fair value is based on independent asset pricing services and models, the inputs of which are market-based or independently sourced market parameters, including but not limited to, yield curves, interest rates, volatilities, market spreads, prepayments, defaults, recoveries, cumulative loss projections, and cash flows. Such securities are classified in Level 2 of the valuation hierarchy. Where Level 1 or Level 2 inputs are not available, such securities are classified as Level 3 within the hierarchy. Fair value determinations of available-for-sale securities are the responsibility of the Company’s corporate accounting and treasury departments. The Company obtains fair value estimates from independent third party vendors on a monthly basis. The vendors’ pricing system methodologies, procedures and system controls are reviewed to ensure they are appropriately designed and operating effectively. The Company reviews the vendors’ inputs for fair value estimates and the recommended assignments of levels within the fair value hierarchy. The review includes the extent to which markets for investment securities are determined to have limited or no activity, or are judged to be active markets. The Company reviews the extent to which observable and unobservable inputs are used as well as the appropriateness of the underlying assumptions about risk that a market participant would use in active markets, with adjustments for limited or inactive markets. In considering the inputs to the fair value estimates, the Company places less reliance on quotes that are judged to not reflect orderly transactions, or are non-binding indications. In assessing credit risk, the Company reviews payment performance, collateral adequacy, third party research and analyses, credit rating histories and issuers’ financial statements. For those markets determined to be inactive or limited, the valuation techniques used are models for which management has verified that discount rates are appropriately adjusted to reflect illiquidity and credit risk. Loans held for sale: loans held for sale measured at fair value, for which an active secondary market and readily available market prices exist, are initially valued at the transaction price and are subsequently valued by using quoted prices for similar assets, adjusted for specific attributes of that loan or other observable market data, such as outstanding commitments from third party investors. Loans held for sale measured at fair value are classified within Level 2. Included in gain on sale of loans were net gains of $994,000 , $0 and $0 for the years ended December 31, 2017 , 2016 and 2015 , respectively, from the changes in fair value of these loans held for sale measured at fair value. Electing to measure loans held for sale at fair value reduces certain timing differences and better matches changes in fair value of these assets with changes in the value of the derivative instruments used to economically hedge them without the burden of complying with the requirements for hedge accounting. Note 20. Fair Value of Assets and Liabilities (continued) Interest rate swap derivative financial instruments: fair values for interest rate swap derivative financial instruments are based upon the estimated amounts to settle the contracts considering current interest rates and are calculated using discounted cash flows that are observable or that can be corroborated by observable market data and, therefore, are classified within Level 2 of the valuation hierarchy. The inputs used to determine fair value include the 3 month LIBOR forward curve to estimate variable rate cash inflows and the Fed Funds Effective Swap Rate to estimate the discount rate. The estimated variable rate cash inflows are compared to the fixed rate outflows and such difference is discounted to a present value to estimate the fair value of the interest rate swaps. The Company also obtains and compares the reasonableness of the pricing from an independent third party. The following tables disclose the fair value measurement of assets and liabilities measured at fair value on a recurring basis: Fair Value Measurements At the End of the Reporting Period Using (Dollars in thousands) Fair Value December 31, 2017 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Investment securities, available-for-sale U.S. government and federal agency $ 31,127 — 31,127 — U.S. government sponsored enterprises 19,091 — 19,091 — State and local governments 629,501 — 629,501 — Corporate bonds 216,762 — 216,762 — Residential mortgage-backed securities 779,283 — 779,283 — Commercial mortgage-backed securities 102,479 — 102,479 — Loans held for sale 38,833 — 38,833 — Total assets measured at fair value on a recurring basis $ 1,817,076 — 1,817,076 — Interest rate swaps $ 9,389 — 9,389 — Total liabilities measured at fair value on a recurring basis $ 9,389 — 9,389 — Note 20. Fair Value of Assets and Liabilities (continued) Fair Value Measurements At the End of the Reporting Period Using (Dollars in thousands) Fair Value December 31, 2016 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Investment securities, available-for-sale U.S. government and federal agency $ 39,407 — 39,407 — U.S. government sponsored enterprises 19,570 — 19,570 — State and local governments 786,373 — 786,373 — Corporate bonds 471,951 — 471,951 — Residential mortgage-backed securities 1,007,515 — 1,007,515 — Commercial mortgage-backed securities 100,661 — 100,661 — Total assets measured at fair value on a recurring basis $ 2,425,477 — 2,425,477 — Interest rate swaps $ 14,725 — 14,725 — Total liabilities measured at fair value on a recurring basis $ 14,725 — 14,725 — Non-recurring Measurements The following is a description of the inputs and valuation methodologies used for assets recorded at fair value on a non-recurring basis, as well as the general classification of such assets pursuant to the valuation hierarchy. There have been no significant changes in the valuation techniques during the period ended December 31, 2017 . Other real estate owned: OREO is carried at the lower of fair value at acquisition date or current estimated fair value, less estimated cost to sell. Estimated fair value of OREO is based on appraisals or evaluations (new or updated). OREO is classified within Level 3 of the fair value hierarchy. Collateral-dependent impaired loans, net of ALLL: loans included in the Company’s loan portfolio for which it is probable that the Company will not collect all principal and interest due according to contractual terms are considered impaired. Estimated fair value of collateral-dependent impaired loans is based on the fair value of the collateral, less estimated cost to sell. Collateral-dependent impaired loans are classified within Level 3 of the fair value hierarchy. The Company’s credit department reviews appraisals for OREO and collateral-dependent loans, giving consideration to the highest and best use of the collateral. The appraisal or evaluation (new or updated) is considered the starting point for determining fair value. The valuation techniques used in preparing appraisals or evaluations (new or updated) include the cost approach, income approach, sales comparison approach, or a combination of the preceding valuation techniques. The key inputs used to determine the fair value of the collateral-dependent loans and OREO include selling costs, discounted cash flow rate or capitalization rate, and adjustment to comparables. Valuations and significant inputs obtained by independent sources are reviewed by the Company for accuracy and reasonableness. The Company also considers other factors and events in the environment that may affect the fair value. The appraisals or evaluations (new or updated) are reviewed at least quarterly and more frequently based on current market conditions, including deterioration in a borrower’s financial condition and when property values may be subject to significant volatility. After review and acceptance of the collateral appraisal or evaluation (new or updated), adjustments to the impaired loan or OREO may occur. The Company generally obtains appraisals or evaluations (new or updated) annually. Note 20. Fair Value of Assets and Liabilities (continued) The following tables disclose the fair value measurement of assets with a recorded change during the period resulting from re-measuring the assets at fair value on a non-recurring basis: Fair Value Measurements At the End of the Reporting Period Using (Dollars in thousands) Fair Value December 31, 2017 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Other real estate owned $ 2,296 — — 2,296 Collateral-dependent impaired loans, net of ALLL 6,339 — — 6,339 Total assets measured at fair value on a non-recurring basis $ 8,635 — — 8,635 Fair Value Measurements At the End of the Reporting Period Using (Dollars in thousands) Fair Value December 31, 2016 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Other real estate owned $ 7,839 — — 7,839 Collateral-dependent impaired loans, net of ALLL 5,664 — — 5,664 Total assets measured at fair value on a non-recurring basis $ 13,503 — — 13,503 Non-recurring Measurements Using Significant Unobservable Inputs (Level 3) The following tables present additional quantitative information about assets measured at fair value on a non-recurring basis and for which the Company has utilized Level 3 inputs to determine fair value: Fair Value Quantitative Information about Level 3 Fair Value Measurements (Dollars in thousands) December 31, Valuation Technique Unobservable Input Range (Weighted- Average) 1 Other real estate owned $ 2,296 Sales comparison approach Selling costs 0.0% - 10.0% (6.0%) Collateral-dependent impaired loans, net of ALLL $ 238 Cost approach Selling costs 10.0% - 20.0% (10.6%) 2,541 Sales comparison approach Selling costs 8.0% - 10.0% (9.4%) 3,560 Combined approach Selling costs 10.0% - 10.0% (10.0%) $ 6,339 Note 20. Fair Value of Assets and Liabilities (continued) Fair Value Quantitative Information about Level 3 Fair Value Measurements (Dollars in thousands) December 31, Valuation Technique Unobservable Input Range (Weighted- Average) 1 Other real estate owned $ 7,767 Sales comparison approach Selling costs 6.0% - 10.0% (6.9%) Adjustment to comparables 0.0% - 10.0% (0.1%) 72 Combined approach Selling costs 10.0% - 10.0% (10.0%) Adjustment to comparables 10.0% - 10.0% (10.0%) $ 7,839 Collateral-dependent impaired loans, net of ALLL $ 110 Cost approach Selling costs 6.0% - 20.0% (6.6%) 1,982 Sales comparison approach Selling costs 8.0% - 10.0% (9.6%) 3,572 Combined approach Selling costs 10.0% - 10.0% (10.0%) Adjustment to comparables 20.0% - 20.0% (20.0%) $ 5,664 ______________________________ 1 The range for selling costs and adjustments to comparables indicate reductions to the fair value. Fair Value of Financial Instruments The following is a description of the methods used to estimate the fair value of all other assets and liabilities recognized at amounts other than fair value. Cash and cash equivalents: fair value is estimated at book value. Investment securities, held-to-maturity: fair value for held-to-maturity securities is estimated in the same manner as available-for-sale securities, which is described above. Loans held for sale: fair value of loans held for sale for which the fair value election has not been made is estimated at book value. Loans receivable, net of ALLL: fair value is estimated by discounting the future cash flows using the rates at which similar notes would be written for the same remaining maturities. The market rates used are based on current rates the Company would impose for similar loans and reflect a market participant assumption about risks associated with non-performance, illiquidity, and the structure and term of the loans along with local economic and market conditions. Estimated fair value of impaired loans is based on the fair value of the collateral, less estimated cost to sell, or the present value of the loan’s expected future cash flows (discounted at the loan’s effective interest rate). All impaired loans are classified as Level 3 and all other loans are classified as Level 2 within the valuation hierarchy. Accrued interest receivable: fair value is estimated at book value. Non-marketable equity securities: fair value is estimated at book value due to restrictions that limit the sale or transfer of such securities. Deposits: fair value of term deposits is estimated by discounting the future cash flows using rates of similar deposits with similar maturities. The market rates used were obtained from an independent third party and reviewed by the Company. The rates were the average of current rates offered by the Company’s local competitors. The estimated fair value of demand deposits such as NOW, DDA, savings, and money market deposit accounts is the book value since rates are regularly adjusted to market rates and transactions are executed at book value daily. Therefore, such deposits are classified in Level 1 of the valuation hierarchy. Certificate accounts and wholesale deposits are classified as Level 2 within the hierarchy. Federal Home Loan Bank advances: fair value of non-callable FHLB advances is estimated by discounting the future cash flows using rates of similar advances with similar maturities. Such rates were obtained from current rates offered by FHLB. The estimated fair value of callable FHLB advances was obtained from FHLB and the model was reviewed by the Company. Note 20. Fair Value of Assets and Liabilities (continued) Securities sold under agreements to repurchase and other borrowed funds: fair value of term repurchase agreements and other term borrowings is estimated based on current repurchase rates and borrowing rates currently available to the Company for repurchases and borrowings with similar terms and maturities. The estimated fair value for overnight repurchase agreements and other borrowings is book value. Subordinated debentures: fair value of the subordinated debt is estimated by discounting the estimated future cash flows using current estimated market rates. The market rates used were averages of currently traded trust preferred securities with similar characteristics to the Company’s issuances and obtained from an independent third party. Accrued interest payable: fair value is estimated at book value. Off-balance sheet financial instruments: unused lines of credit and letters of credit represent the principal categories of off-balance sheet financial instruments. The fair value of commitments is based on fees currently charged to enter into similar agreements, taking into account the remaining terms of the agreements and the counterparties’ credit standing. The fair value of unused lines of credit and letters of credit is not material; therefore, such commitments are not included in the following tables. The following tables present the carrying amounts, estimated fair values and the level within the fair value hierarchy of the Company’s financial instruments: Fair Value Measurements At the End of the Reporting Period Using (Dollars in thousands) Carrying Amount December 31, 2017 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial assets Cash and cash equivalents $ 200,004 200,004 — — Investment securities, available-for-sale 1,778,243 — 1,778,243 — Investment securities, held-to-maturity 648,313 — 660,086 — Loans held for sale 38,833 — 38,833 — Loans receivable, net of ALLL 6,448,256 — 6,219,515 114,771 Accrued interest receivable 44,462 44,462 — — Non-marketable equity securities 29,884 — 29,884 — Total financial assets $ 9,187,995 244,466 8,726,561 114,771 Financial liabilities Deposits $ 7,579,747 6,602,445 978,803 — FHLB advances 353,995 — 352,886 — Repurchase agreements and other borrowed funds 370,797 — 370,797 — Subordinated debentures 126,135 — 98,023 — Accrued interest payable 3,450 3,450 — — Interest rate swaps 9,389 — 9,389 — Total financial liabilities $ 8,443,513 6,605,895 1,809,898 — Note 20. Fair Value of Assets and Liabilities (continued) Fair Value Measurements At the End of the Reporting Period Using (Dollars in thousands) Carrying Amount December 31, 2016 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial assets Cash and cash equivalents $ 152,541 152,541 — — Investment securities, available-for-sale 2,425,477 — 2,425,477 — Investment securities, held-to-maturity 675,674 — 689,089 — Loans held for sale 72,927 72,927 — — Loans receivable, net of ALLL 5,554,891 — 5,380,286 123,382 Accrued interest receivable 45,832 45,832 — — Non-marketable equity securities 25,550 — 25,550 — Total financial assets $ 8,952,892 271,300 8,520,402 123,382 Financial liabilities Deposits $ 7,372,279 6,090,879 1,283,532 — FHLB advances 251,749 — 257,643 — Repurchase agreements and other borrowed funds 478,090 — 478,090 — Subordinated debentures 125,991 — 85,557 — Accrued interest payable 3,584 3,584 — — Interest rate swaps 14,725 — 14,725 — Total financial liabilities $ 8,246,418 6,094,463 2,119,547 —

Contingencies and Commitments

Contingencies and Commitments	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Contingencies and Commitments	Contingencies and Commitments The Company is a party to financial instruments with off-balance sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to extend credit and letters of credit, and involve, to varying degrees, elements of credit risk. The Company’s exposure to credit loss in the event of nonperformance by the other party to the financial instrument for commitments to extend credit is represented by the contractual amount of those instruments. The Company uses the same credit policies in making commitments and conditional obligations as it does for on-balance sheet instruments. The Company had the following outstanding commitments: (Dollars in thousands) December 31, December 31, Unused lines of credit $ 1,565,112 1,325,236 Letters of credit 40,082 26,162 Total outstanding commitments $ 1,605,194 1,351,398 The Company is a defendant in legal proceedings arising in the normal course of business. In the opinion of management, the disposition of pending litigation will not have a material affect on the Company’s consolidated financial position, results of operations or liquidity.

Mergers and Acquisitions

Mergers and Acquisitions	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Mergers and Acquisitions	Mergers and Acquisitions On April 30, 2017 , the Company acquired 100 percent of the outstanding common stock of TFB Bancorp, Inc. and its wholly-owned subsidiary, The Foothills Bank, a community bank based in Yuma, Arizona. Foothills provides banking services to individuals and businesses in Arizona, with banking offices located in Yuma, Prescott and Casa Grande, Arizona. The acquisition expands the Company’s market into the state of Arizona and further diversifies the Company’s loan, customer and deposit base. Foothills merged into the Bank and operates as a separate Bank division under its existing name and management team. The Foothills acquisition was valued at $64,015,000 and resulted in the Company issuing 1,381,661 shares of its common stock and $17,342,000 in cash in exchange for all of Foothills’ outstanding common stock shares. The fair value of the Company shares issued was determined on the basis of the closing market price of the Company’s common stock on the April 30, 2017 acquisition date. The excess of the fair value of consideration transferred over total identifiable net assets was recorded as goodwill. The goodwill arising from the acquisition consists largely of the synergies and economies of scale expected from combining the operations of the Company and Foothills. None of the goodwill is deductible for income tax purposes as the acquisition was accounted for as a tax-free exchange. On August 31, 2016 , the Company acquired 100 percent of the outstanding common stock of Treasure State Bank, a community bank based in Missoula, Montana. TSB provides banking services to individuals and businesses in the greater Missoula market. TSB merged into the Bank and became a part of the First Security Bank of Missoula bank division. The TSB acquisition was valued at $13,940,000 and resulted in the Company issuing 349,545 shares of its common stock and $3,475,000 in cash in exchange for all of TSB’s outstanding common stock shares. The fair value of the Company shares issued was determined on the basis of the closing market price of the Company’s common stock on the August 31, 2016 acquisition date. The excess of the fair value of consideration transferred over total identifiable net assets was recorded as goodwill. The goodwill arising from the acquisition consists largely of the synergies and economies of scale expected from combining the operations of the Company and TSB. None of the goodwill is deductible for income tax purposes as the acquisition was accounted for as a tax-free exchange. The assets and liabilities of Foothills and TSB were recorded on the Company’s consolidated statements of financial condition at their estimated fair values as of the April 30, 2017 and August 31, 2016 acquisition dates, respectively, and their results of operations have been included in the Company’s consolidated statements of operations since those dates. The following table discloses the calculation of the fair value of the consideration transferred, the total identifiable net assets acquired and the resulting goodwill arising from the Foothills and TSB acquisitions: Foothills TSB (Dollars in thousands) April 30, August 31, Fair value of consideration transferred Fair value of Company shares issued, net of equity issuance costs $ 46,673 10,465 Cash consideration for outstanding shares 17,342 3,475 Contingent consideration — — Total fair value of consideration transferred 64,015 13,940 Recognized amounts of identifiable assets acquired and liabilities assumed Identifiable assets acquired Cash and cash equivalents 13,251 10,176 Investment securities 25,420 — Loans receivable 292,529 51,875 Core deposit intangible 1 4,331 762 Accrued income and other assets 19,699 6,937 Total identifiable assets acquired 355,230 69,750 Liabilities assumed Deposits 296,760 58,364 FHLB advances 22,800 3,260 Accrued expenses and other liabilities 2,264 601 Total liabilities assumed 321,824 62,225 Total identifiable net assets 33,406 7,525 Goodwill recognized $ 30,609 6,415 ______________________________ 1 The core deposit intangible for each acquisition was determined to have an estimated life of 10 years . Note 22. Mergers and Acquisitions (continued) The fair value of the Foothills and TSB assets acquired includes loans with fair values of $292,529,000 and $51,875,000 , respectively. The gross principal and contractual interest due under the Foothills and TSB contracts is $303,527,000 and $54,819,000 , respectively. The Company evaluated the principal and contractual interest due at each of the acquisition dates and determined that insignificant amounts were not expected to be collectible. The Company incurred $1,127,000 of third-party acquisition-related costs in connection with the Foothills acquisition during the year ended December 31, 2017 . The Company incurred $456,000 of third-party acquisition-related costs in connection with the TSB acquisition during the year ended December 31, 2016. The expenses are included in other expense in the Company's consolidated statements of operations. Total income consisting of net interest income and non-interest income of the acquired operations of Foothills was approximately $13,625,000 and net income was approximately $2,626,000 from April 30, 2017 to December 31, 2017. The following unaudited pro forma summary presents consolidated information of the Company as if the Foothills acquisition had occurred on January 1, 2016: Years ended (Dollars in thousands) December 31, December 31, Net interest income and non-interest income $ 462,603 436,678 Net income 114,187 124,373 Total income consisting of net interest income and non-interest income of the acquired operations of TSB was approximately $1,800,000 and net income was approximately $897,000 from August 31, 2016 to December 31, 2016. The following unaudited pro forma summary presents consolidated information of the Company as if the TSB acquisition had occurred on January 1, 2015: Years ended (Dollars in thousands) December 31, December 31, Net interest income and non-interest income $ 424,242 392,252 Net income 120,929 116,577

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On January 31, 2018, the Company acquired 100 percent of the outstanding common stock of Columbine Capital Corp., and its wholly-owned subsidiary, Collegiate Peaks Bank, a community bank based in Buena Vista, Colorado. Collegiate provides banking services to businesses and individuals in the Mountain and Front Range communities of Colorado, with banking offices located in Aurora, Buena Vista, Denver and Salida. Collegiate will operate as a division of the Bank under the name “Collegiate Peaks Bank, division of Glacier Bank.” The Collegiate acquisition was valued at $96,083,000 and resulted in the Company issuing common stock and paying cash and other considerations in exchange for all of Collegiate's outstanding common stock shares. The fair value of the Company shares issued was determined on the basis of the closing market price of the Company's common stock shares on the January 31, 2018 acquisition date. The initial accounting for the Collegiate acquisition has not been completed because the fair value of financial assets, financial liabilities and goodwill have not yet been determined. As a result of the closing of the Collegiate acquisition, the Company crossed the $10 billion asset threshold and will now be subject to heightened regulations required by the Dodd-Frank Act. The Company will be required to, among other requirements: 1) perform annual stress tests; 2) calculate its FDIC deposit assessment base using a performance score and a loss-severity score system; and 3) be examined for compliance with federal consumer protection laws primarily by the Consumer Financial Protection Bureau (the “CFPB”). The Company will also be subject to the interchange fee cap imposed by the Durbin Amendment to the Dodd-Frank Act, which is expected to have a significant financial impact to the Company’s earnings.

Nature of Operations and Summ32

Nature of Operations and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General	General Glacier Bancorp, Inc. (“Company”) is a Montana corporation headquartered in Kalispell, Montana. The Company provides a full range of banking services to individuals and businesses in Montana, Idaho, Utah, Washington, Wyoming, Colorado and Arizona through its wholly-owned bank subsidiary, Glacier Bank (“Bank”). The Company offers a wide range of banking products and services, including: 1) retail banking; 2) business banking; 3) real estate, commercial, agriculture and consumer loans; and 4) mortgage origination services. The Company serves individuals, small to medium-sized businesses, community organizations and public entities. The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of income and expenses during the reporting period. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change include: 1) the determination of the allowance for loan and lease losses (“ALLL” or “allowance”); 2) the valuation of investment securities; 3) the valuation of real estate acquired in connection with foreclosures or in satisfaction of loans; and 4) the evaluation of goodwill impairment. For the determination of the ALLL and real estate valuation estimates, management obtains independent appraisals (new or updated) for significant items. Estimates relating to investment valuations are obtained from independent third parties. Estimates relating to the evaluation of goodwill for impairment are determined based on internal calculations using significant independent party inputs.
Principles of Consolidation	Principles of Consolidation The consolidated financial statements of the Company include the parent holding company and the Bank. The Bank consists of fourteen bank divisions, a treasury division, an information technology division and a centralized mortgage division. The treasury division includes the Bank’s investment portfolio and wholesale borrowings, the information technology division includes the Bank’s internal data processing, and the centralized mortgage division includes mortgage loan servicing and secondary market sales. The Bank divisions operate under separate names, management teams and advisory directors. The Company considers the Bank to be its sole operating segment as the Bank 1) engages in similar bank business activity from which it earns revenues and incurs expenses; 2) the operating results of the Bank are regularly reviewed by the Chief Executive Officer (“CEO”) (i.e., the chief operating decision maker) who makes decisions about resources to be allocated to the Bank; and 3) financial information is available for the Bank. All significant inter-company transactions have been eliminated in consolidation. The Bank has subsidiary interests in variable interest entities (“VIE”) for which the Bank has both the power to direct the VIE’s significant activities and the obligation to absorb losses or right to receive benefits of the VIE that could potentially be significant to the VIE. These subsidiary interests are included in the Company’s consolidated financial statements. The Bank also has subsidiary interests in VIEs for which the Bank does not have a controlling financial interest and is not the primary beneficiary. These subsidiary interests are not included in the Company’s consolidated financial statements. The parent holding company owns non-bank subsidiaries that have issued trust preferred securities as Tier 1 capital instruments. The trust subsidiaries are not included in the Company’s consolidated financial statements. The Company's investments in the trust subsidiaries are included in non-marketable equity securities on the Company's statements of financial condition. In April 2017, the Company completed its acquisition of TFB Bancorp, Inc. and its wholly-owned subsidiary, The Foothills Bank, a community bank based in Yuma, Arizona (collectively, “Foothills”). In August 2016, the Company completed its acquisition of Treasure State Bank (“TSB”), a community bank based in Missoula, Montana. In October 2015, the Company completed its acquisition of Cañon Bank Corporation and its wholly-owned subsidiary, Cañon National Bank, a community bank based in Cañon City, Colorado (collectively, “Cañon”). In February 2015, the Company completed its acquisition of Montana Community Banks, Inc. and its wholly-owned subsidiary, Community Bank, Inc., a community bank based in Ronan, Montana (collectively, “CB”). The transactions were accounted for using the acquisition method, and their results of operations have been included in the Company’s consolidated financial statements as of the acquisition dates. For additional information relating to recent mergers and acquisitions, see Note 22. In January 2018, the Company acquired the outstanding common stock of Columbine Capital Corp., and its wholly-owned subsidiary, Collegiate Peaks Bank, a community bank based in Buena Vista, Colorado (collectively, “Collegiate”). As of December 31, 2017, Collegiate had total assets of $532,958,000 , gross loans of $345,687,000 and total deposits of $463,970,000 . For additional information relating to this subsequent event, see Note 23. Note 1. Nature of Operations and Summary of Significant Accounting Policies (continued) In October 2017, the Company announced the signing of a definitive agreement to acquire Inter-Mountain Bancorp, Inc. and its wholly-owned subsidiary, First Security Bank, a community bank based in Bozeman, Montana (collectively, “FSB”). FSB provides banking services to individuals and businesses throughout Montana with banking offices located in Bozeman, Belgrade, Big Sky, Choteau, Fairfield, Fort Benton, Three Forks, Vaughn and West Yellowstone. As of December 31, 2017, FSB had total assets of $1,027,685,000 , gross loans of $639,880,000 and total deposits of $891,390,000 . Upon closing of the transaction, which is anticipated to take place in February 2018, FSB will become a new bank division headquartered in Bozeman. Big Sky Western Bank, the Bank’s existing Bozeman-based division will combine with the new FSB division. The agriculture-focused northern branches of FSB, located in the area known as the Golden Triangle, will combine with the Bank’s First Bank of Montana division.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents include cash on hand, cash held as demand deposits at various banks and the Federal Reserve Bank (“FRB”), interest bearing deposits, federal funds sold, and liquid investments with original maturities of three months or less. The Bank is required to maintain an average reserve balance with either the FRB or in the form of cash on hand. The required reserve balance at December 31, 2017 was $10,916,000 .
Investment Securities	Investment Securities Debt securities for which the Company has the positive intent and ability to hold to maturity are classified as held-to-maturity and are carried at amortized cost. Debt and equity securities held primarily for the purpose of selling in the near term are classified as trading securities and are reported at fair value, with unrealized gains and losses included in income. Debt and equity securities not classified as held-to-maturity or trading are classified as available-for-sale and are reported at fair value with unrealized gains and losses, net of income taxes, as a separate component of other comprehensive income (“OCI”). Premiums and discounts on investment securities are amortized or accreted into income using a method that approximates the interest method. The objective of the interest method is to calculate periodic interest income at a constant effective yield. The Company does not have any investment securities classified as trading securities. The Company reviews and analyzes the various risks that may be present within the investment portfolio on an ongoing basis, including market risk and credit risk. Market risk is the risk to an entity’s financial condition resulting from adverse changes in the value of its holdings arising from movements in interest rates, foreign exchange rates, equity prices or commodity prices. The Company assesses the market risk of individual securities as well as the investment portfolio as a whole. Credit risk, broadly defined, is the risk that an issuer or counterparty will fail to perform on an obligation. A security is investment grade if the issuer has an adequate capacity to meet its commitment over the expected life of the investment, i.e., the risk of default is low and full and timely repayment of interest and principal is expected. To determine investment grade status for securities, the Company conducts due diligence of the creditworthiness of the issuer or counterparty prior to acquisition and ongoing thereafter consistent with the risk characteristics of the security and the overall risk of the investment portfolio. Credit quality due diligence takes into account the extent to which a security is guaranteed by the U.S. government and other agencies of the U.S. government. The depth of the due diligence is based on the complexity of the structure, the size of the security, and takes into account material positions and specific groups of securities or stratifications for analysis and review of similar risk positions. The due diligence includes consideration of payment performance, collateral adequacy, internal analyses, third party research and analytics, external credit ratings and default statistics. For additional information relating to investment securities, see Note 2.
Temporary versus Other-Than-Temporary Impairment	Temporary versus Other-Than-Temporary Impairment The Company assesses individual securities in its investment portfolio for impairment at least on a quarterly basis, and more frequently when economic or market conditions warrant. An investment is impaired if the fair value of the security is less than its carrying value at the financial statement date. If impairment is determined to be other-than-temporary, an impairment loss is recognized by reducing the amortized cost for the credit loss portion of the impairment with a corresponding charge to earnings for a like amount. In evaluating impaired securities for other-than-temporary impairment losses, management considers 1) the severity and duration of the impairment; 2) the credit ratings of the security; and 3) the overall deal structure, including the Company’s position within the structure, the overall and near term financial performance of the issuer and underlying collateral, delinquencies, defaults, loss severities, recoveries, prepayments, cumulative loss projections, discounted cash flows and fair value estimates. Note 1. Nature of Operations and Summary of Significant Accounting Policies (continued) In evaluating debt securities for other-than-temporary impairment losses, management assesses whether the Company intends to sell the security or if it is more-likely-than-not that the Company will be required to sell the debt security. In so doing, management considers contractual constraints, liquidity, capital, asset/liability management and securities portfolio objectives. If impairment is determined to be other-than-temporary and the Company does not intend to sell a debt security, and it is more-likely-than-not the Company will not be required to sell the security before recovery of its cost basis, it recognizes the credit component of an other-than-temporary impairment of a debt security in earnings and the remaining portion (noncredit portion) in OCI, net of tax. For held-to-maturity debt securities, the amount of an other-than-temporary impairment recorded in OCI for the noncredit portion of a previous other-than-temporary impairment is amortized prospectively, as an increase to the carrying amount of the security, over the remaining life of the security on the basis of the timing of future estimated cash flows of the security. If impairment is determined to be other-than-temporary and the Company intends to sell a debt security or it is more-likely-than-not the Company will be required to sell the security before recovery of its cost basis, it recognizes the entire amount of the other-than-temporary impairment in earnings. For debt securities with other-than-temporary impairment, the previous amortized cost basis less the other-than-temporary impairment recognized in earnings shall be the new amortized cost basis of the security. In subsequent periods, the Company accretes into interest income the difference between the new amortized cost basis and cash flows expected to be collected prospectively over the life of the debt security.
Loans Held for Sale	Loans Held for Sale Loans held for sale generally consist of long-term, fixed rate, conforming, single-family residential real estate loans intended to be sold on the secondary market. Loans held for sale may be carried at the lower of cost or estimated fair value in the aggregate basis, or at fair value where the Company has elected the fair value option. When an election is made to carry the loans held for sale at fair value, the fair value includes the servicing value of the loans and any change in fair value is recognized in non-interest income. Fair value elections are made at the time of origination or purchase based on the Company’s fair value election policy. Beginning in 2017, the Company elected fair value accounting for all of its loans held for sale.
Loans Receivable	Loans Receivable Loans that are intended to be held-to-maturity are reported at the unpaid principal balance less net charge-offs and adjusted for deferred fees and costs on originated loans and unamortized premiums or discounts on acquired loans. Fees and costs on originated loans and premiums or discounts on acquired loans are deferred and subsequently amortized or accreted as a yield adjustment over the expected life of the loan utilizing the interest method. The objective of the interest method is to calculate periodic interest income at a constant effective yield. When a loan is paid off prior to maturity, the remaining fees and costs on originated loans and premiums or discounts on acquired loans are immediately recognized into interest income. The Company’s loan segments, which are based on the purpose of the loan, include residential real estate, commercial, and consumer loans. The Company’s loan classes, a further disaggregation of segments, include residential real estate loans (residential real estate segment), commercial real estate and other commercial loans (commercial segment), and home equity and other consumer loans (consumer segment). Loans that are thirty days or more past due based on payments received and applied to the loan are considered delinquent. Loans are designated non-accrual and the accrual of interest is discontinued when the collection of the contractual principal or interest is unlikely. A loan is typically placed on non-accrual when principal or interest is due and has remained unpaid for ninety days or more. When a loan is placed on non-accrual status, interest previously accrued but not collected is reversed against current period interest income. Subsequent payments on non-accrual loans are applied to the outstanding principal balance if doubt remains as to the ultimate collectability of the loan. Interest accruals are not resumed on partially charged-off impaired loans. For other loans on nonaccrual, interest accruals are resumed on such loans only when they are brought fully current with respect to interest and principal and when, in the judgment of management, the loans are estimated to be fully collectible as to both principal and interest. Note 1. Nature of Operations and Summary of Significant Accounting Policies (continued) The Company considers impaired loans to be the primary credit quality indicator for monitoring the credit quality of the loan portfolio. Loans are designated impaired when, based upon current information and events, it is probable that the Company will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement and, therefore, the Company has serious doubts as to the ability of such borrowers to fulfill the contractual obligation. Impaired loans include non-performing loans (i.e., non-accrual loans and accruing loans ninety days or more past due) and accruing loans under ninety days past due where it is probable payments will not be received according to the loan agreement (e.g., troubled debt restructuring). Interest income on accruing impaired loans is recognized using the interest method. The Company measures impairment on a loan-by-loan basis in the same manner for each class within the loan portfolio. An insignificant delay or shortfall in the amounts of payments would not cause a loan or lease to be considered impaired. The Company determines the significance of payment delays and shortfalls on a case-by-case basis, taking into consideration all of the facts and circumstances surrounding the loan and the borrower, including the length and reasons for the delay, the borrower’s prior payment record, and the amount of the shortfall in relation to the principal and interest due. A restructured loan is considered a troubled debt restructuring (“TDR”) if the creditor, for economic or legal reasons related to the debtor’s financial difficulties, grants a concession to the debtor that it would not otherwise consider. The Company periodically enters into restructure agreements with borrowers whereby the loans were previously identified as TDRs. When such circumstances occur, the Company carefully evaluates the facts of the subsequent restructure to determine the appropriate accounting and under certain circumstances it may be acceptable not to account for the subsequently restructured loan as a TDR. When assessing whether a concession has been granted by the Company, any prior forgiveness on a cumulative basis is considered a continuing concession. A TDR loan is considered an impaired loan and a specific valuation allowance is established when the fair value of the collateral-dependent loan or present value of the loan’s expected future cash flows (discounted at the loan’s effective interest rate based on the original contractual rate) is lower than the carrying value of the impaired loan. The Company has made the following types of loan modifications, some of which were considered a TDR: • reduction of the stated interest rate for the remaining term of the debt; • extension of the maturity date(s) at a stated rate of interest lower than the current market rate for newly originated debt having similar risk characteristics; and • reduction of the face amount of the debt as stated in the debt agreements. The Company recognizes that while borrowers may experience deterioration in their financial condition, many continue to be creditworthy customers who have the willingness and capacity for debt repayment. In determining whether non-restructured or unimpaired loans issued to a single or related party group of borrowers should continue to accrue interest when the borrower has other loans that are impaired or are TDRs, the Company on a quarterly or more frequent basis performs an updated and comprehensive assessment of the willingness and capacity of the borrowers to timely and ultimately repay their total debt obligations, including contingent obligations. Such analysis takes into account current financial information about the borrowers and financially responsible guarantors, if any, including for example: • analysis of global, i.e., aggregate debt service for total debt obligations; • assessment of the value and security protection of collateral pledged using current market conditions and alternative market assumptions across a variety of potential future situations; and • loan structures and related covenants. For additional information relating to loans, see Note 3.
Allowance for Loan and Lease Losses	Allowance for Loan and Lease Losses Based upon management’s analysis of the Company’s loan portfolio, the balance of the ALLL is an estimate of probable credit losses known and inherent within the Bank’s loan portfolio as of the date of the consolidated financial statements. The ALLL is analyzed at the loan class level and is maintained within a range of estimated losses. Determining the adequacy of the ALLL involves a high degree of judgment and is inevitably imprecise as the risk of loss is difficult to quantify. The determination of the ALLL and the related provision for loan losses is a critical accounting estimate that involves management’s judgments about known relevant internal and external environmental factors that affect loan losses. The balance of the ALLL is highly dependent upon management’s evaluations of borrowers’ current and prospective performance, appraisals and other variables affecting the quality of the loan portfolio. Individually significant loans and major lending areas are reviewed periodically to determine potential problems at an early date. Changes in management’s estimates and assumptions are reasonably possible and may have a material impact upon the Company’s consolidated financial statements, results of operations or capital. Note 1. Nature of Operations and Summary of Significant Accounting Policies (continued) Risk characteristics considered in the ALLL analysis applicable to each loan class within the Company's loan portfolio are as follows: Residential Real Estate. Residential real estate loans are secured by owner-occupied 1-4 family residences. Repayment of these loans is primarily dependent on the personal income and credit rating of the borrowers. Credit risk in these loans is impacted by economic conditions within the Company’s market areas that affect the value of the property securing the loans and affect the borrowers' personal incomes. Mitigating risk factors for this loan class include a large number of borrowers, geographic dispersion of market areas and the loans are originated for relatively smaller amounts. Commercial Real Estate . Commercial real estate loans typically involve larger principal amounts, and repayment of these loans is generally dependent on the successful operation of the property securing the loan and/or the business conducted on the property securing the loan. Credit risk in these loans is impacted by the creditworthiness of a borrower, valuation of the property securing the loan and conditions within the local economies in the Company’s diverse, geographic market areas. Commercial . Commercial loans consist of loans to commercial customers for use in financing working capital needs, equipment purchases and business expansions. The loans in this category are repaid primarily from the cash flow of a borrower’s principal business operation. Credit risk in these loans is driven by creditworthiness of a borrower and the economic conditions that impact the cash flow stability from business operations across the Company’s diverse, geographic market areas. Home Equity . Home equity loans consist of junior lien mortgages and first and junior lien lines of credit (revolving open-end and amortizing closed-end) secured by owner-occupied 1-4 family residences. Repayment of these loans is primarily dependent on the personal income and credit rating of the borrowers. Credit risk in these loans is impacted by economic conditions within the Company’s market areas that affect the value of the residential property securing the loans and affect the borrowers' personal incomes. Mitigating risk factors for this loan class are a large number of borrowers, geographic dispersion of market areas and the loans are originated for terms that range from 10 years to 15 years . Other Consumer . The other consumer loan portfolio consists of various short-term loans such as automobile loans and loans for other personal purposes. Repayment of these loans is primarily dependent on the personal income of the borrowers. Credit risk is driven by consumer economic factors (such as unemployment and general economic conditions in the Company’s diverse, geographic market area) and the creditworthiness of a borrower. The ALLL consists of a specific valuation allowance component and a general valuation allowance component. The specific component relates to loans that are determined to be impaired and individually evaluated for impairment. The Company measures impairment on a loan-by-loan basis based on the present value of expected future cash flows discounted at the loan’s effective interest rate, except when it is determined that repayment of the loan is expected to be provided solely by the underlying collateral. For impairment based on expected future cash flows, the Company considers all information available as of a measurement date, including past events, current conditions, potential prepayments, and estimated cost to sell when such costs are expected to reduce the cash flows available to repay or otherwise satisfy the loan. For alternative ranges of cash flows, the likelihood of the possible outcomes is considered in determining the best estimate of expected future cash flows. The effective interest rate for a loan restructured in a TDR is based on the original contractual rate. For collateral-dependent loans and real estate loans for which foreclosure or a deed-in-lieu of foreclosure is probable, impairment is measured by the fair value of the collateral, less estimated cost to sell. The fair value of the collateral is determined primarily based upon appraisal or evaluation of the underlying real property value. The general valuation allowance component relates to probable credit losses inherent in the balance of the loan portfolio based on historical loss experience, adjusted for changes in trends and conditions of qualitative or environmental factors. The historical loss experience is based on the previous twelve quarters loss experience by loan class adjusted for risk characteristics in the existing loan portfolio. The same trends and conditions are evaluated for each class within the loan portfolio; however, the risk characteristics are weighted separately at the individual class level based on the Company’s judgment and experience. Note 1. Nature of Operations and Summary of Significant Accounting Policies (continued) The changes in trends and conditions evaluated for each class within the loan portfolio include the following: • changes in lending policies and procedures, including changes in underwriting standards and collection, charge-off, and recovery practices not considered elsewhere in estimating credit losses; • changes in global, national, regional, and local economic and business conditions and developments that affect the collectability of the portfolio, including the condition of various market segments; • changes in the nature and volume of the portfolio and in the terms of loans; • changes in experience, ability, and depth of lending management and other relevant staff; • changes in the volume and severity of past due and nonaccrual loans; • changes in the quality of the Company’s loan review system; • changes in the value of underlying collateral for collateral-dependent loans; • the existence and effect of any concentrations of credit, and changes in the level of such concentrations; and • the effect of other external factors such as competition and legal and regulatory requirements on the level of estimated credit losses in the Company’s existing portfolio. The ALLL is increased by provisions for loan losses which are charged to expense. The portions of loan and overdraft balances determined by management to be uncollectible are charged off as a reduction of the ALLL and recoveries of amounts previously charged off are credited as an increase to the ALLL. The Company’s charge-off policy is consistent with bank regulatory standards. Consumer loans generally are charged off when the loan becomes over 120 days delinquent. Real estate acquired as a result of foreclosure or by deed-in-lieu of foreclosure is classified as OREO until such time as it is sold. At acquisition date, the assets and liabilities of acquired banks are recorded at their estimated fair values which results in no ALLL carried over from acquired banks. Subsequent to acquisition, an allowance will be recorded on the acquired loan portfolios for further credit deterioration, if any.
Premises and Equipment	Premises and Equipment Premises and equipment are accounted for at cost less depreciation. Depreciation is computed on a straight-line method over the estimated useful lives or the term of the related lease. The estimated useful life for office buildings is 15 - 40 years and the estimated useful life for furniture, fixtures, and equipment is 3 - 10 years. Interest is capitalized for any significant building projects. For additional information relating to premises and equipment, see Note 4.
Leases	Leases The Company leases certain land, premises and equipment from third parties under operating and capital leases. The lease payments for operating lease agreements are recognized on a straight-line basis. The present value of the future minimum rental payments for capital leases is recognized as an asset when the lease is formed. Lease improvements incurred at the inception of the lease are recorded as an asset and depreciated over the initial term of the lease and lease improvements incurred subsequently are depreciated over the remaining term of the lease. For additional information relating to leases, see Note 4.
Other Real Estate Owned	Other Real Estate Owned Property acquired by foreclosure or deed-in-lieu of foreclosure is initially recorded at fair value, less estimated selling cost, at acquisition date (i.e., cost of the property). The Company is considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loan upon the occurrence of either the Company obtaining legal title to the property or the borrower conveying all interest in the property through a deed-in-lieu or similar agreement. Fair value is determined as the amount that could be reasonably expected in a current sale between a willing buyer and a willing seller in an orderly transaction between market participants at the measurement date. Subsequent to the initial acquisition, if the fair value of the asset, less estimated selling cost, is less than the cost of the property, a loss is recognized in other expense and the asset carrying value is reduced. Gain or loss on disposition of other real estate owned (“OREO”) is recorded in non-interest income or non-interest expense, respectively. In determining the fair value of the properties on the date of transfer and any subsequent estimated losses of net realizable value, the fair value of other real estate acquired by foreclosure or deed-in-lieu of foreclosure is determined primarily based upon appraisal or evaluation of the underlying property value.
Long-lived Assets	Long-lived Assets Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. An asset is deemed impaired if the sum of the expected future cash flows is less than the carrying amount of the asset. If impaired, an impairment loss is recognized in other expense to reduce the carrying value of the asset to fair value. At December 31, 2017 and 2016 , no long-lived assets were considered materially impaired.
Business Combinations and Intangible Assets	Business Combinations and Intangible Assets Acquisition accounting requires the total purchase price to be allocated to the estimated fair values of assets acquired and liabilities assumed, including certain intangible assets. Goodwill is recorded if the purchase price exceeds the net fair value of assets acquired and a bargain purchase gain is recorded in other income if the net fair value of assets acquired exceeds the purchase price. Adjustment of the allocated purchase price may be related to fair value estimates for which all information has not been obtained of the acquired entity known or discovered during the allocation period, the period of time required to identify and measure the fair values of the assets and liabilities acquired in the business combination. The allocation period is generally limited to one year following consummation of a business combination. Core deposit intangible represents the intangible value of depositor relationships resulting from deposit liabilities assumed in acquisitions and is amortized using an accelerated method based on an estimated runoff of the related deposits. The core deposit intangible is evaluated for impairment and recoverability whenever events or changes in circumstances indicate that its carrying amount may not be recoverable, with any changes in estimated useful life accounted for prospectively over the revised remaining life. For additional information relating to core deposit intangibles, see Note 5. The Company tests goodwill for impairment at the reporting unit level annually during the third quarter. The Company has identified that each of the Bank divisions are reporting units (i.e., components of the Glacier Bank operating segment) given that each division has a separate management team that regularly reviews its respective division financial information; however, the reporting units are aggregated into a single reporting unit due to the reporting units having similar economic characteristics. The goodwill of a reporting unit is tested for impairment between annual tests if an event occurs or circumstances change that would more-likely-than-not reduce the fair value of a reporting unit below its carrying amount. Examples of events and circumstances that could trigger the need for interim impairment testing include: • a significant change in legal factors or in the business climate; • an adverse action or assessment by a regulator; • unanticipated competition; • a loss of key personnel; • a more-likely-than-not expectation that a reporting unit or a significant portion of a reporting unit will be sold or otherwise disposed of; and • the testing for recoverability of a significant asset group within a reporting unit. For the goodwill impairment assessment, the Company has the option, prior to the two-step process, to first assess qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more-likely-than-not that the fair value of a reporting unit is less than its carrying value. The Company opted to bypass the qualitative assessment for its 2017 and 2016 annual goodwill impairment testing and proceed directly to the two -step goodwill impairment test. The goodwill impairment two-step process requires the Company to make assumptions and judgments regarding fair value. In the first step, the Company calculates an implied fair value based on a control premium analysis. If the implied fair value is less than the carrying value, the second step is completed to compute the impairment amount, if any, by determining the “implied fair value” of goodwill. This determination requires the allocation of the estimated fair value of the reporting units to the assets and liabilities of the reporting units. Any remaining unallocated fair value represents the “implied fair value” of goodwill, which is compared to the corresponding carrying value of goodwill to compute impairment, if any. For additional information relating to goodwill, see Note 5.
Non-Marketable Equity Securities	Non-Marketable Equity Securities Non-marketable equity securities primarily consist of Federal Home Loan Bank (“FHLB”) stock. FHLB stock is restricted because such stock may only be sold to FHLB at its par value. Due to restrictive terms, and the lack of a readily determinable market value, FHLB stock is carried at cost. The investments in FHLB stock are required investments related to the Company’s borrowings from FHLB. FHLB obtains its funding primarily through issuance of consolidated obligations of the FHLB system. The U.S. government does not guarantee these obligations, and each of the regional FHLBs is jointly and severally liable for repayment of each other’s debt.
Bank-Owned Life Insurance	Bank-Owned Life Insurance The Company maintains bank-owned life insurance policies on certain current and former employees and directors, which are recorded at their cash surrender values as determined by the insurance carriers. At December 31, 2017 and 2016 , the carrying value associated with these policies is $59,351,000 and $50,451,000 , respectively, and is recorded in other assets in the Company’s statements of financial position. The appreciation in the cash surrender value of the policies is recognized as a component of other non-interest income in the Company’s statements of operations.
Derivatives and Hedging Activities	Derivatives and Hedging Activities For asset and liability management purposes, the Company has entered into interest rate swap agreements to hedge against changes in forecasted cash flows due to interest rate exposures. The interest rate swaps are recognized as assets or liabilities on the Company’s statements of financial condition and measured at fair value. Fair value estimates are obtained from third parties and are based on pricing models. The Company does not enter into interest rate swap agreements for trading or speculative purposes. The Company takes into account the impact of bilateral collateral and master netting agreements that allows the Company to settle all interest rate swap agreements held with a single counterparty on a net basis, and to offset the net interest rate swap derivative position with the related collateral when recognizing interest rate swap derivative assets and liabilities. Interest rate swaps are contracts in which a series of interest payments are exchanged over a prescribed period. The notional amount upon which the interest payments are based is not exchanged. The swap agreements are derivative instruments and convert a portion of the Company’s forecasted variable rate debt to a fixed rate (i.e., cash flow hedge) over the payment term of the interest rate swap. The effective portion of the gain or loss on the cash flow hedging instruments is initially reported as a component of OCI and subsequently reclassified into earnings in the same period during which the transaction affects earnings. The ineffective portion of the gain or loss on derivative instruments, if any, is recognized in earnings. For the years ended December 31, 2017 , 2016 , and 2015 , the Company’s cash flow hedges were determined to be fully effective. Interest rate derivative financial instruments receive hedge accounting treatment only if they are designated as a hedge and are expected to be, and are, highly effective in substantially reducing interest rate risk arising from the assets and liabilities identified as exposing the Company to risk. Derivative financial instruments that do not meet specified hedging criteria are recorded at fair value with changes in fair value recorded in income. The Company’s interest rate swaps are considered highly effective and currently meet the hedge accounting criteria. Cash flows resulting from the interest rate derivative financial instruments that are accounted for as hedges of assets and liabilities are classified in the Company’s cash flow statement in the same category as the cash flows of the items being hedged. For additional information relating to interest rate swap agreements, see Note 10. At December 31, 2017 , the Company also had residential real estate derivatives for 1) commitments to fund certain residential real estate loans (interest rate locks) of $67,861,000 to be sold into the secondary market; and 2) forward commitments for the future delivery of residential real estate loans to third party investors on a best efforts basis. It is the Company’s practice to enter into forward commitments for the future delivery of residential real estate loans when interest rate lock commitments are entered into in order to economically hedge the effect of changes in interest rates resulting from its commitments to fund the loans. These derivatives are not designated in hedge relationships. Such derivatives are short-term in nature and changes in the fair values of these derivatives are not recorded as gains on sale of loans because the changes were not significant.
Stock-based Compensation	Stock-based Compensation Stock-based compensation awards granted are valued at fair value and compensation cost is recognized on a straight-line basis over the requisite service period of each award. The impact of forfeitures of stock-based compensation awards on compensation expense is recognized as forfeitures occur. For additional information relating to stock-based compensation, see Note 12.
Advertising and Promotion	Advertising and Promotion Advertising and promotion costs are recognized in the period incurred.
Income Taxes	Income Taxes The Company’s income tax expense consists of current and deferred income tax expense. Current income tax expense reflects taxes to be paid or refunded for the current period by applying the provisions of enacted tax law to earnings or losses. Deferred income tax expense results from changes in deferred assets and liabilities between periods. The Company recognizes interest and penalties related to income tax matters in income tax expense. Note 1. Nature of Operations and Summary of Significant Accounting Policies (continued) Deferred tax assets and liabilities are recognized for estimated future income tax consequences attributable to differences between the financial statement carrying amounts of assets and liabilities and their respective tax bases. The effect on deferred tax assets and liabilities of a change in income tax rates is recognized in income in the period that includes the enactment date. Deferred tax assets are reduced by a valuation allowance if, based on the weight of available evidence, it is more-likely-than-not that some portion or all of the deferred tax assets will not be realized. The term more-likely-than-not means a likelihood of more than fifty percent . The recognition threshold considers the facts, circumstances, and information available at the reporting date and is subject to the Company’s judgment. In assessing the need for a valuation allowance, the Company considers both positive and negative evidence. For additional information relating to income taxes, see Note 15.
Comprehensive Income	Comprehensive Income Comprehensive income consists of net income and OCI. OCI includes unrealized gains and losses, net of tax effect, on available-for-sale securities and derivatives used for cash flow hedges. For additional information relating to OCI, see Note 16.
Earnings Per Share	Earnings Per Share Basic earnings per share is computed by dividing net income by the weighted-average number of shares of common stock outstanding during the period presented. Diluted earnings per share is computed by including the net increase in shares as if dilutive outstanding stock options were exercised and restricted stock awards were vested, using the treasury stock method. For additional information relating to earnings per share, see Note 17.
Reclassifications	Reclassifications Certain reclassifications have been made to the 2016 and 2015 financial statements to conform to the 2017 presentation.
Accounting Guidance Adopted in 2017 and Pending Adoption at December 31, 2017	Accounting Guidance Adopted in 2017 The Accounting Standards Codification ™ (“ASC”) is the Financial Accounting Standards Board’s (“FASB”) officially recognized source of authoritative GAAP applicable to all public and non-public non-governmental entities. Rules and interpretive releases of the Securities and Exchange Commission (“SEC”) under the authority of the federal securities laws are also sources of authoritative GAAP for the Company as an SEC registrant. All other accounting literature is non-authoritative. The following paragraphs provide descriptions of recently adopted accounting standards that may have had a material effect on the Company’s financial position or results of operations. Comprehensive Income. In February 2018, FASB amended ASC Topic 220 to allow a reclassification from accumulated other comprehensive income (“AOCI”) to retained earnings for stranded tax effects resulting from the newly enacted Tax Cuts and Jobs Act (“Tax Act”). The amount of the reclassification consists of the difference between the historical corporate income tax rates and the newly enacted 21 percent corporate income tax rate. The amendments are effective for all entities for the interim and annual reporting periods beginning after December 15, 2018 and early adoption is permitted, including interim periods in those years. The Company adopted the amendments as of December 31, 2017, which resulted in a net reclassification of $351,000 between AOCI and retained earnings. The Company’s policy is to release material stranded tax effects on a specific identification basis. Stock Compensation. In March 2016, FASB amended ASC Topic 718 to address certain aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification of awards on the statements of cash flows. The amendments were effective for public business entities for the first interim and annual reporting periods beginning after December 15, 2016 and the Company adopted the amendments as of January 1, 2017. The amendments require entities to recognize all income tax effects related to share-based payment awards in the statements of operations when the awards vest or are settled. Previously, income tax benefits at the settlement of awards were reported as increases (or decreases) to additional paid-in capital to the extent that those benefits were greater than (or less than) the income tax benefits recognized in earnings during the awards’ vesting periods. Such amounts are to be classified as an operating activity in the statements of cash flows instead of the prior accounting treatment, which required it to be classified as both an operating and a financing activity. The Company has elected to apply this classification change on a retrospective basis. Also in connection with the adoption of the Update, the Company has elected to change its accounting policy to recognize forfeitures as they occur. The requirement to report income tax effects in earnings has been applied to the settlement of awards on a prospective basis and the impact of applying the guidance reduced reported income tax expense for the year ended December 31, 2017 by $553,000 , or approximately $0.01 per diluted common share. The implementation of the remaining provisions of the Update did not have a significant impact on the Company’s consolidated financial statements. Note 1. Nature of Operations and Summary of Significant Accounting Policies (continued) Accounting Guidance Pending Adoption at December 31, 2017 The following paragraphs provide descriptions of newly issued but not yet effective accounting standards that could have a material effect on the Company’s financial position or results of operations. Derivatives and Hedging. In August 2017, FASB amended ASC Topic 815 to improve the financial reporting of hedging relationships to better portray the economic results of an entity’s risk management activities in its financial statements. In addition, the amendments made targeted improvements to simplify the application of the hedge accounting guidance. The amendments are effective for public business entities for the first interim and annual reporting periods beginning after December 15, 2018 and early adoption is permitted. The Company is currently evaluating the full impact of the amendments on its existing interest rate swaps and whether it will early adopt. The Company does not expect there to be an impact to the Company’s financial position and results of operations, although, there may be additional financial statement disclosures. The accounting policies and procedures will be modified after the Company has fully evaluated the standard, although significant changes are not expected. For additional information on derivatives, see Note 10. Receivables - Nonrefundable Fees and Other Costs. In March 2017, FASB amended ASC Subtopic 310-20 to shorten the amortization period for certain callable debt securities held at a premium. Specifically, the amendments require the premium to be amortized to the earliest call date instead of the maturity date. The amendments do not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. The amendments are effective for public business entities for the first interim and annual reporting periods beginning after December 15, 2018. Early adoption is permitted and if adopted in an interim period, any adjustments should be reflected as of the beginning of the year that includes the interim period. The entity should apply the amendments on a modified retrospective basis through a cumulative-effective adjustment directly to retained earnings as of the beginning of the period of adoption. The Company has premiums on debt securities that are currently being amortized to the maturity date, primarily in the state and local governments category. If the Company were to adopt these amendments as of January 1, 2018, the Company estimates that $21,219,000 of the premium associated with debt securities would be adjusted to retained earnings. The Company is still determining when it will adopt these amendments and accounting policies and procedures will be modified upon adoption of the standard. Goodwill and Other Intangibles. In January 2017, FASB amended ASC Topic 350 to simplify the measurement of goodwill by eliminating Step 2 from the goodwill impairment test. Instead, under these amendments, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss should not exceed the total amount of goodwill allocated to that reporting unit. The amendments are effective for public business entities for the first interim and annual reporting periods beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company has goodwill from prior business combinations and performs an annual impairment test or more frequently if changes or circumstances occur that would more-likely-than-not reduce the fair value of the reporting unit below its carrying value. During the third quarter of 2017, the Company performed its impairment assessment and determined the fair value of the aggregated reporting units exceed the carrying value, such that the Company’s goodwill was not considered impaired. Although the Company cannot anticipate future goodwill impairment assessments, based on the most recent assessment, it is unlikely that an impairment amount would need to be calculated and, therefore, the Company does not anticipate a material impact from these amendments to the Company’s financial position and results of operations. The current accounting policies and processes are not anticipated to change, except for the elimination of the Step 2 analysis. For additional information regarding goodwill impairment testing, see Note 5. Financial Instruments. In June 2016, FASB amended ASC Topic 326 to replace the incurred loss model with a methodology that reflects expected credit losses over the life of the loan and requires consideration of a broader range of reasonable and supportable information to calculate credit loss estimates. The amendments are effective for public business entities for the first interim and annual reporting periods beginning after December 15, 2019. The Company is currently evaluating the impact of these amendments to the Company’s financial position and results of operations and currently does not know or cannot reasonably quantify the impact of the adoption of the amendments as a result of the complexity and extensive changes from the amendments. The ALLL is a material estimate of the Company and given the change from an incurred loss model to a methodology that considers the credit loss over the life of the loan, there is the potential for an increase in the ALLL at adoption date. The Company is anticipating a significant change in the processes and procedures to calculate the ALLL, including changes in assumptions and estimates to consider expected credit losses over the life of the loan versus the current accounting practice that utilizes the incurred loss model. The Company will also develop new procedures for determining an allowance for credit losses relating to held-to-maturity investment securities. In addition, the current accounting policy and procedures for other-than-temporary impairment on available-for-sale investment securities will be replaced with an allowance approach. The Company has formed a project team and is actively reviewing the standard for developing and implementing processes and procedures during the next two years to ensure it is fully compliant with the amendments at adoption date. For additional information on the ALLL, see Note 3. Note 1. Nature of Operations and Summary of Significant Accounting Policies (continued) Leases. In February 2016, FASB amended ASC Topic 842 to address several aspects of lease accounting with the significant change being the recognition of lease assets and lease liabilities for leases previously classified as operating leases. The amendments are effective for public business entities for the first interim and annual reporting periods beginning after December 15, 2018, and early adoption is permitted. The Company has several lease agreements for which the amendments will require the Company to recognize a lease liability to make lease payments and a right-of-use asset which will represent its right to use the underlying asset for the lease term. The Company is currently reviewing the amendments to ensure it is fully compliant by the adoption date and doesn’t expect to early adopt. As permitted by the amendments, the Company is anticipating electing an accounting policy to not recognize lease assets and lease liabilities for leases with a term of twelve months or less. The impact is not expected to have a material effect on the Company’s financial position or results of operations since the Company does not have a material amount of lease agreements. The Company is currently in the process of fully evaluating the amendments and will subsequently implement new processes, which are not expected to significantly change, since the Company already has processes for certain lease agreements that recognize the lease assets and lease liabilities. In addition, the Company will change its current accounting policies to comply with the amendments with such changes as mentioned above. For additional information on the Company’s leases, see Note 4. Financial Instruments. In January 2016, FASB amended ASC Topic 825 to address certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. The amendments are effective for public business entities for the first interim and annual reporting periods beginning after December 15, 2017. Early adoption is only permitted under certain circumstances outlined in the amendments. A reporting entity should apply the amendments by means of a cumulative-effect adjustment to the Company’s statements of financial condition as of the beginning of the reporting year of adoption. The amendments will impact the Company in a few areas including requiring equity investments (with certain exclusions) to be measured at fair value with the changes recognized in net income, requirement to utilize an exit price when measuring the fair value of financial instruments, additional disclosures related to OCI, evaluation of a valuation allowance on a deferred tax asset related to available-for-sale investment securities in combination with the entity’s other deferred tax assets, and other disclosure changes. The Company is currently evaluating the impact of these amendments, but does not expect them to have a material effect on the Company’s equity securities, financial position or results of operations. However, the amendments will have an impact on certain items that are disclosed at fair value that are not currently utilizing the exit price notion when measuring fair value. As of December 31, 2017 , the Company cannot quantify the change in the fair value of such disclosures since the Company is currently finalizing the full impact of the Update. The Company has developed processes to comply with the disclosure requirements of such amendments and accounting policies and procedures will be updated and implemented upon adoption of the standard. For additional information on fair value of assets and liabilities, see Note 20. Revenue Recognition. In May 2014, FASB amended ASC Topic 606 to clarify the principles for recognizing revenue and develop a common revenue standard among industries. The new guidance establishes the following core principle: recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for goods or services. Five steps are provided for a company or organization to follow to achieve such core principle. The new guidance also includes a cohesive set of disclosure requirements that will provide users of financial statements with comprehensive information about the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. The entity should apply the amendments using one of two retrospective methods described in the amendment. Accounting Standards Update No. 2015-14, Revenue from Contracts with Customers (Topic 606) delayed the effective date for public entities to annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period. Several subsequent amendments have been issued that provide clarifying guidance and are effective with the adoption of the original Update. The Company has finalized its assessment of the Update and has identified the revenue line items within the scope of the new guidance. The majority of the Company’s revenue sources, such as interest income from investment securities and loans, fee income from loans and gain on sale of loans, are not within the scope of Topic 606. Conversely, the Company has evaluated the revenue sources determined to be in scope of Topic 606, including service charges and fee income on deposits and gain or loss on sale of OREO. The Company has determined the adoption of this guidance will not have a significant impact to the Company’s financial position or results of operations; however, beginning January 2018, updated policies and procedures on the sale of OREO will be implemented and additional quantitative and qualitative disclosures about the Company’s revenue may need to be incorporated into the notes to the financial statements.

Investment Securities (Tables)

Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Amortized cost, gross unrealized gains and losses and the fair value of investment securities	The following tables present the amortized cost, the gross unrealized gains and losses and the fair value of the Company’s investment securities: December 31, 2017 Amortized Cost Gross Unrealized Fair Value (Dollars in thousands) Gains Losses Available-for-sale U.S. government and federal agency $ 31,216 54 (143 ) 31,127 U.S. government sponsored enterprises 19,195 — (104 ) 19,091 State and local governments 614,366 20,299 (5,164 ) 629,501 Corporate bonds 216,443 802 (483 ) 216,762 Residential mortgage-backed securities 785,960 1,253 (7,930 ) 779,283 Commercial mortgage-backed securities 104,324 25 (1,870 ) 102,479 Total available-for-sale 1,771,504 22,433 (15,694 ) 1,778,243 Held-to-maturity State and local governments 648,313 20,346 (8,573 ) 660,086 Total held-to-maturity 648,313 20,346 (8,573 ) 660,086 Total investment securities $ 2,419,817 42,779 (24,267 ) 2,438,329 December 31, 2016 Amortized Cost Gross Unrealized Fair Value (Dollars in thousands) Gains Losses Available-for-sale U.S. government and federal agency $ 39,554 15 (162 ) 39,407 U.S. government sponsored enterprises 19,557 55 (42 ) 19,570 State and local governments 775,395 20,941 (9,963 ) 786,373 Corporate bonds 471,569 1,175 (793 ) 471,951 Residential mortgage-backed securities 1,014,518 2,744 (9,747 ) 1,007,515 Commercial mortgage-backed securities 102,209 30 (1,578 ) 100,661 Total available-for-sale 2,422,802 24,960 (22,285 ) 2,425,477 Held-to-maturity State and local governments 675,674 21,400 (7,985 ) 689,089 Total held-to-maturity 675,674 21,400 (7,985 ) 689,089 Total investment securities $ 3,098,476 46,360 (30,270 ) 3,114,566
Amortized cost and fair value of securities by contractual maturity	The following table presents the amortized cost and fair value of available-for-sale and held-to-maturity securities by contractual maturity at December 31, 2017 . Actual maturities may differ from expected or contractual maturities since issuers have the right to prepay obligations with or without prepayment penalties. December 31, 2017 Available-for-Sale Held-to-Maturity (Dollars in thousands) Amortized Cost Fair Value Amortized Cost Fair Value Due within one year $ 69,596 69,650 — — Due after one year through five years 228,415 228,881 2,108 2,136 Due after five years through ten years 228,766 236,318 86,741 88,264 Due after ten years 354,443 361,632 559,464 569,686 881,220 896,481 648,313 660,086 Mortgage-backed securities 1 890,284 881,762 — — Total $ 1,771,504 1,778,243 648,313 660,086 ______________________________ 1 Mortgage-backed securities, which have prepayment provisions, are not assigned to maturity categories due to fluctuations in their prepayment speeds.
Proceeds from sales and calls of investment securities and associated gains and losses	Proceeds from sales and calls of investment securities and the associated gains and losses that have been included in earnings are listed below: Years ended (Dollars in thousands) December 31, December 31, December 31, Available-for-sale Proceeds from sales and calls of investment securities $ 280,783 212,140 167,660 Gross realized gains 1 3,369 2,459 1,877 Gross realized losses 1 (4,005 ) (3,794 ) (1,808 ) Held-to-maturity Proceeds from calls of investment securities 23,020 25,405 20,997 Gross realized gains 1 204 97 50 Gross realized losses 1 (228 ) (225 ) (100 ) ______________________________ 1 The gain or loss on the sale or call of each investment security is determined by the specific identification method.
Summary of investment securities with an unrealized loss position	Investment securities with an unrealized loss position are summarized as follows: December 31, 2017 Less than 12 Months 12 Months or More Total (Dollars in thousands) Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Available-for-sale U.S. government and federal agency $ 1,208 (5 ) 13,179 (138 ) 14,387 (143 ) U.S. government sponsored enterprises 14,926 (56 ) 3,425 (48 ) 18,351 (104 ) State and local governments 61,126 (689 ) 121,181 (4,475 ) 182,307 (5,164 ) Corporate bonds 99,636 (264 ) 29,034 (219 ) 128,670 (483 ) Residential mortgage-backed securities 372,175 (3,050 ) 254,721 (4,880 ) 626,896 (7,930 ) Commercial mortgage-backed securities 37,650 (469 ) 62,968 (1,401 ) 100,618 (1,870 ) Total available-for-sale $ 586,721 (4,533 ) 484,508 (11,161 ) 1,071,229 (15,694 ) Held-to-maturity State and local governments $ 21,207 (186 ) 105,486 (8,387 ) 126,693 (8,573 ) Total held-to-maturity $ 21,207 (186 ) 105,486 (8,387 ) 126,693 (8,573 ) December 31, 2016 Less than 12 Months 12 Months or More Total (Dollars in thousands) Fair Value Unrealized Loss Fair Value Unrealized Loss Fair Value Unrealized Loss Available-for-sale U.S. government and federal agency $ 6,718 (24 ) 26,239 (138 ) 32,957 (162 ) U.S. government sponsored enterprises 6,049 (42 ) — — 6,049 (42 ) State and local governments 222,700 (4,949 ) 81,783 (5,014 ) 304,483 (9,963 ) Corporate bonds 174,821 (774 ) 6,141 (19 ) 180,962 (793 ) Residential mortgage-backed securities 688,811 (9,079 ) 29,957 (668 ) 718,768 (9,747 ) Commercial mortgage-backed securities 89,298 (1,578 ) — — 89,298 (1,578 ) Total available-for-sale $ 1,188,397 (16,446 ) 144,120 (5,839 ) 1,332,517 (22,285 ) Held-to-maturity State and local governments $ 117,912 (1,712 ) 86,601 (6,273 ) 204,513 (7,985 ) Total held-to-maturity $ 117,912 (1,712 ) 86,601 (6,273 ) 204,513 (7,985 )

Loans Receivable, Net (Tables)

Loans Receivable, Net (Tables)	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Summary of loans receivable	The following table presents loans receivable for each portfolio class of loans: At or for the Years ended (Dollars in thousands) December 31, December 31, Residential real estate loans $ 720,728 674,347 Commercial loans Real estate 3,577,139 2,990,141 Other commercial 1,579,353 1,342,250 Total 5,156,492 4,332,391 Consumer and other loans Home equity 457,918 434,774 Other consumer 242,686 242,951 Total 700,604 677,725 Loans receivable 6,577,824 5,684,463 Allowance for loan and lease losses (129,568 ) (129,572 ) Loans receivable, net $ 6,448,256 5,554,891 Net deferred origination (fees) costs included in loans receivable $ (2,643 ) (1,228 ) Net purchase accounting (discounts) premiums included in loans receivable $ (16,325 ) (12,144 ) Weighted-average interest rate on loans (tax-equivalent) 4.81 % 4.77 %
Summary of the activity in the ALLL	The following tables summarize the activity in the ALLL by portfolio segment: Year ended December 31, 2017 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Balance at beginning of period $ 129,572 12,436 65,773 37,823 7,572 5,968 Provision for loan losses 10,824 (1,521 ) 7,152 2,545 (1,103 ) 3,751 Charge-offs (19,331 ) (199 ) (6,188 ) (2,856 ) (489 ) (9,599 ) Recoveries 8,503 82 1,778 1,791 224 4,628 Balance at end of period $ 129,568 10,798 68,515 39,303 6,204 4,748 Year ended December 31, 2016 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Balance at beginning of period $ 129,697 14,427 67,877 32,525 8,998 5,870 Provision for loan losses 2,333 (1,734 ) (2,686 ) 5,164 (520 ) 2,109 Charge-offs (11,496 ) (464 ) (3,082 ) (1,778 ) (1,185 ) (4,987 ) Recoveries 9,038 207 3,664 1,912 279 2,976 Balance at end of period $ 129,572 12,436 65,773 37,823 7,572 5,968 Note 3. Loans Receivable, Net (continued) Year ended December 31, 2015 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Balance at beginning of period $ 129,753 14,680 67,799 30,891 9,963 6,420 Provision for loan losses 2,284 640 (696 ) 3,030 (480 ) (210 ) Charge-offs (7,002 ) (985 ) (1,920 ) (2,322 ) (809 ) (966 ) Recoveries 4,662 92 2,694 926 324 626 Balance at end of period $ 129,697 14,427 67,877 32,525 8,998 5,870
Summary of recorded investment in loans and the balance in the ALLL	The following tables disclose the recorded investment in loans and the balance in the ALLL by portfolio segment: December 31, 2017 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Loans receivable Individually evaluated for impairment $ 119,994 12,399 77,536 23,032 3,755 3,272 Collectively evaluated for impairment 6,457,830 708,329 3,499,603 1,556,321 454,163 239,414 Total loans receivable $ 6,577,824 720,728 3,577,139 1,579,353 457,918 242,686 ALLL Individually evaluated for impairment $ 5,223 246 500 3,851 56 570 Collectively evaluated for impairment 124,345 10,552 68,015 35,452 6,148 4,178 Total ALLL $ 129,568 10,798 68,515 39,303 6,204 4,748 December 31, 2016 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Loans receivable Individually evaluated for impairment $ 130,263 11,612 85,634 23,950 5,934 3,133 Collectively evaluated for impairment 5,554,200 662,735 2,904,507 1,318,300 428,840 239,818 Total loans receivable $ 5,684,463 674,347 2,990,141 1,342,250 434,774 242,951 ALLL Individually evaluated for impairment $ 6,881 856 922 4,419 296 388 Collectively evaluated for impairment 122,691 11,580 64,851 33,404 7,276 5,580 Total ALLL $ 129,572 12,436 65,773 37,823 7,572 5,968
Summary of the impaired loans	The following tables disclose information related to impaired loans by portfolio segment: At or for the Year ended December 31, 2017 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Loans with a specific valuation allowance Recorded balance $ 17,689 2,978 4,545 8,183 186 1,797 Unpaid principal balance 18,400 3,046 4,573 8,378 199 2,204 Specific valuation allowance 5,223 246 500 3,851 56 570 Average balance 18,986 2,928 5,851 8,477 359 1,371 Loans without a specific valuation allowance Recorded balance 102,305 9,421 72,991 14,849 3,569 1,475 Unpaid principal balance 122,833 10,380 89,839 16,931 4,098 1,585 Average balance 107,945 9,834 76,427 15,129 4,734 1,821 Total Recorded balance 119,994 12,399 77,536 23,032 3,755 3,272 Unpaid principal balance 141,233 13,426 94,412 25,309 4,297 3,789 Specific valuation allowance 5,223 246 500 3,851 56 570 Average balance 126,931 12,762 82,278 23,606 5,093 3,192 At or for the Year ended December 31, 2016 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Loans with a specific valuation allowance Recorded balance $ 22,128 2,759 9,129 8,814 334 1,092 Unpaid principal balance 22,374 2,825 9,130 8,929 345 1,145 Specific valuation allowance 6,881 856 922 4,419 296 388 Average balance 26,745 4,942 10,441 9,840 257 1,265 Loans without a specific valuation allowance Recorded balance 108,135 8,853 76,505 15,136 5,600 2,041 Unpaid principal balance 131,059 9,925 94,180 17,724 7,120 2,110 Average balance 108,827 12,858 72,323 15,537 6,004 2,105 Total Recorded balance 130,263 11,612 85,634 23,950 5,934 3,133 Unpaid principal balance 153,433 12,750 103,310 26,653 7,465 3,255 Specific valuation allowance 6,881 856 922 4,419 296 388 Average balance 135,572 17,800 82,764 25,377 6,261 3,370
Loan portfolio aging analysis	The following tables present an aging analysis of the recorded investment in loans by portfolio segment: December 31, 2017 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Accruing loans 30-59 days past due $ 26,375 6,252 12,546 3,634 2,142 1,801 Accruing loans 60-89 days past due 11,312 794 5,367 3,502 987 662 Accruing loans 90 days or more past due 6,077 2,366 609 2,973 — 129 Non-accrual loans 44,833 4,924 27,331 8,298 3,338 942 Total past due and non-accrual loans 88,597 14,336 45,853 18,407 6,467 3,534 Current loans receivable 6,489,227 706,392 3,531,286 1,560,946 451,451 239,152 Total loans receivable $ 6,577,824 720,728 3,577,139 1,579,353 457,918 242,686 December 31, 2016 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Accruing loans 30-59 days past due $ 20,599 6,338 5,079 5,388 2,439 1,355 Accruing loans 60-89 days past due 5,018 1,398 754 1,352 844 670 Accruing loans 90 days or more past due 1,099 266 145 283 191 214 Non-accrual loans 49,332 4,528 30,216 8,817 5,240 531 Total past due and non-accrual loans 76,048 12,530 36,194 15,840 8,714 2,770 Current loans receivable 5,608,415 661,817 2,953,947 1,326,410 426,060 240,181 Total loans receivable $ 5,684,463 674,347 2,990,141 1,342,250 434,774 242,951
Summary of TDRs	The following tables present TDRs that occurred during the periods presented and the TDRs that occurred within the previous twelve months that subsequently defaulted during the periods presented: Year ended December 31, 2017 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer TDRs that occurred during the period Number of loans 32 5 13 11 2 1 Pre-modification recorded balance $ 41,521 841 31,109 9,403 158 10 Post-modification recorded balance $ 38,838 841 28,426 9,403 158 10 TDRs that subsequently defaulted Number of loans 1 — — 1 — — Recorded balance $ 18 — — 18 — — Note 3. Loans Receivable, Net (continued) Year ended December 31, 2016 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer TDRs that occurred during the period Number of loans 34 — 10 21 3 — Pre-modification recorded balance $ 22,907 — 8,454 14,183 270 — Post-modification recorded balance $ 22,848 — 8,415 14,166 267 — TDRs that subsequently defaulted Number of loans 1 — — 1 — — Recorded balance $ 6 — — 6 — — Year ended December 31, 2015 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer TDRs that occurred during the period Number of loans 64 3 25 22 1 13 Pre-modification recorded balance $ 22,316 2,259 8,877 10,545 137 498 Post-modification recorded balance $ 23,110 2,203 9,927 10,325 157 498 TDRs that subsequently defaulted Number of loans 7 1 1 4 — 1 Recorded balance $ 2,556 1,947 78 529 — 2

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Premises and equipment, net of accumulated depreciation	Premises and equipment, net of accumulated depreciation, consist of the following: (Dollars in thousands) December 31, 2017 December 31, 2016 Land $ 31,370 29,648 Office buildings and construction in progress 182,592 173,886 Furniture, fixtures and equipment 83,177 84,559 Leasehold improvements 8,085 7,853 Accumulated depreciation (127,876 ) (119,748 ) Net premises and equipment $ 177,348 176,198
Future Minimum Rental Commitments required under Operating and Capital Leases	The total future minimum rental commitments required under operating and capital leases that have initial or remaining noncancelable lease terms in excess of one year at December 31, 2017 are as follows: (Dollars in thousands) Capital Leases Operating Leases Total Years ending December 31, 2018 $ 92 2,633 2,725 2019 92 2,502 2,594 2020 92 2,039 2,131 2021 11 1,593 1,604 2022 — 953 953 Thereafter — 5,541 5,541 Total minimum lease payments 287 15,261 15,548 Less: Amount representing interest 27 Present value of minimum lease payments 260 Less: Current portion of obligations under capital leases 79 Long-term portion of obligations under capital leases $ 181

Other Intangible Assets and G36

Other Intangible Assets and Goodwill (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of core deposit intangibles	The following table sets forth information regarding the Company’s core deposit intangibles: At or for the Years ended (Dollars in thousands) December 31, December 31, December 31, Gross carrying value $ 21,649 21,943 38,527 Accumulated amortization (7,465 ) (9,596 ) (23,972 ) Net carrying value $ 14,184 12,347 14,555 Aggregate amortization expense $ 2,494 2,970 2,964 Estimated amortization expense for the years ending December 31, 2018 $ 2,209 2019 2,100 2020 2,027 2021 1,952 2022 1,871
Changes in the carrying value of goodwill	The following schedule discloses the changes in the carrying value of goodwill: Years ended (Dollars in thousands) December 31, December 31, December 31, Net carrying value at beginning of period $ 147,053 140,638 129,706 Acquisitions and adjustments 30,758 6,415 10,932 Net carrying value at end of period $ 177,811 147,053 140,638

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	12 Months Ended
	Dec. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Carrying amounts of consolidated VIEs' assets and liabilities	The following table summarizes the carrying amounts of the consolidated VIEs’ assets and liabilities included in the Company’s statements of financial condition and are adjusted for intercompany eliminations. All assets presented can be used only to settle obligations of the consolidated VIEs and all liabilities presented consist of liabilities for which creditors and other beneficial interest holders therein have no recourse to the general credit of the Company. (Dollars in thousands) December 31, December 31, Assets Loans receivable $ 57,796 36,950 Accrued interest receivable 94 120 Other assets 15,885 10,024 Total assets $ 73,775 47,094 Liabilities Other borrowed funds $ 7,964 4,105 Accrued interest payable 1 2 Other liabilities 98 27 Total liabilities $ 8,063 4,134
Amortization expense and tax credits and other tax benefits recognized for qualified affordable housing project investments	The following table summarizes the amortization expense and the amount of tax credits and other tax benefits recognized for qualified affordable housing project investments during the periods presented. Years ended (Dollars in thousands) December 31, 2017 December 31, 2016 December 31, Amortization expense $ 2,507 1,125 974 Tax credits and other tax benefits recognized 3,827 1,515 1,552

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2017
Deposits [Abstract]
Scheduled maturities of time deposits	The scheduled maturities of time deposits are as follows: (Dollars in thousands) Amount Years ending December 31, 2018 $ 557,693 2019 120,657 2020 65,284 2021 45,409 2022 27,974 Thereafter 242 $ 817,259

Borrowings (Tables)

Borrowings (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Carrying Value of Repurchase Agreements by Maturity and Category of Collateral	The following tables summarize the carrying value of the Company’s repurchase agreements by remaining contractual maturity and category of collateral: December 31, 2017 Remaining Contractual Maturity of the Agreements (Dollars in thousands) Overnight and Continuous Up to 30 Days Total Residential mortgage-backed securities $ 360,751 — 360,751 Commercial mortgage-backed securities 1,822 — 1,822 Total $ 362,573 — 362,573 December 31, 2016 Remaining Contractual Maturity of the Agreements (Dollars in thousands) Overnight and Continuous Up to 30 Days Total Residential mortgage-backed securities $ 471,706 643 472,349 Commercial mortgage-backed securities 1,301 — 1,301 Total $ 473,007 643 473,650
Maturities of FHLB Advances	The scheduled maturities of FHLB advances consist of the following: December 31, 2017 December 31, 2016 (Dollars in thousands) Amount Weighted Rate Amount Weighted Rate Maturing within one year $ 200,869 1.64 % $ 41,099 0.84 % Maturing one year through two years 887 2.05 % 70,983 1.42 % Maturing two years through three years 1,651 3.58 % 927 2.16 % Maturing three years through four years 148,721 2.69 % 1,728 3.66 % Maturing four years through five years 945 5.25 % 135,000 3.08 % Thereafter 922 5.42 % 2,012 5.33 % Total $ 353,995 2.11 % $ 251,749 2.27 %

Subordinated Debentures (Tables

Subordinated Debentures (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Instruments [Abstract]
Summary of Subordinated Debentures	The terms of the subordinated debentures, arranged by maturity date, are reflected in the table below. The amounts include fair value adjustments from acquisitions. December 31, 2017 Variable Rate Structure Maturity Date (Dollars in thousands) Balance Rate First Company Statutory Trust 2001 $ 3,269 4.680 % 3 month LIBOR plus 3.30% 07/31/2031 First Company Statutory Trust 2003 2,407 4.925 % 3 month LIBOR plus 3.25% 03/26/2033 Glacier Capital Trust II 46,393 4.109 % 3 month LIBOR plus 2.75% 04/07/2034 Citizens (ID) Statutory Trust I 5,155 4.250 % 3 month LIBOR plus 2.65% 06/17/2034 Glacier Capital Trust III 36,083 2.649 % 3 month LIBOR plus 1.29% 04/07/2036 Glacier Capital Trust IV 30,928 3.158 % 3 month LIBOR plus 1.57% 09/15/2036 Bank of the San Juans Bancorporation Trust I 1,900 3.301 % 3 month LIBOR plus 1.82% 03/01/2037 $ 126,135

Derivatives and Hedging Activ41

Derivatives and Hedging Activities (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of Interest Rate Swap Derivative Financial Instruments	The Company’s interest rate swap derivative financial instruments as of December 31, 2017 are as follows: (Dollars in thousands) Forecasted Notional Amount Variable Interest Rate 1 Fixed Interest Rate 1 Payment Term Interest rate swap $ 160,000 3 month LIBOR 3.378 % Oct. 21, 2014 - Oct. 21, 2021 Interest rate swap 100,000 3 month LIBOR 2.498 % Nov. 30, 2015 - Nov. 30, 2022 ______________________________ 1 The Company pays the fixed interest rate and the counterparty pays the Company the variable interest rate.
Summary of Pre-Tax Gains or Losses	The following table presents the pre-tax gains or losses recorded in OCI and the Company’s statements of operations relating to the interest rate swap derivative financial instruments: Years ended (Dollars in thousands) December 31, December 31, December 31, Interest rate swaps Amount of gain (loss) recognized in OCI (effective portion) $ 444 (1,643 ) (7,857 ) Amount of loss reclassified from OCI to interest expense (4,892 ) (6,417 ) (5,025 ) Amount of loss recognized in other non-interest expense (ineffective portion) — — —
Offsetting Liabilities	The following table discloses the offsetting of financial liabilities and interest rate swap derivative liabilities. There were no interest rate swap derivative assets at the dates presented. December 31, 2017 December 31, 2016 (Dollars in thousands) Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Statements of Financial Position Net Amounts of Liabilities Presented in the Statements of Financial Position Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Statements of Financial Position Net Amounts of Liabilities Presented in the Statements of Financial Position Interest rate swaps $ 9,389 — 9,389 14,725 — 14,725

Regulatory Capital (Tables)

Regulatory Capital (Tables)	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Capital adequacy guidelines and compliance	The following tables illustrate the FRB’s adequacy guidelines and the Company’s and the Bank’s compliance with those guidelines: December 31, 2017 Actual Required for Capital Adequacy Purposes To Be Well Capitalized Under Prompt Corrective Action Regulations (Dollars in thousands) Amount Ratio Amount Ratio Amount Ratio Total capital (to risk-weighted assets) Consolidated $ 1,232,089 15.64 % $ 630,109 8.00 % N/A N/A Glacier Bank 1,182,509 15.04 % 628,823 8.00 % $ 786,029 10.00 % Tier 1 capital (to risk-weighted assets) Consolidated 1,133,125 14.39 % 472,582 6.00 % N/A N/A Glacier Bank 1,083,744 13.79 % 471,617 6.00 % 628,823 8.00 % Common Equity Tier 1 (to risk-weighted assets) Consolidated 1,009,276 12.81 % 354,437 4.50 % N/A N/A Glacier Bank 1,083,744 13.79 % 353,713 4.50 % 510,919 6.50 % Tier 1 capital (to average assets) Consolidated 1,133,125 11.90 % 380,770 4.00 % N/A N/A Glacier Bank 1,083,744 11.47 % 377,809 4.00 % 472,261 5.00 % Note 11. Regulatory Capital (continued) December 31, 2016 Actual Required for Capital Adequacy Purposes To Be Well Capitalized (Dollars in thousands) Amount Ratio Amount Ratio Amount Ratio Total capital (to risk-weighted assets) Consolidated $ 1,179,673 16.38 % $ 576,092 8.00 % N/A N/A Glacier Bank 1,131,949 15.76 % 574,658 8.00 % $ 718,323 10.00 % Tier 1 capital (to risk-weighted assets) Consolidated 1,089,142 15.12 % 432,069 6.00 % N/A N/A Glacier Bank 1,041,640 14.50 % 430,994 6.00 % 574,658 8.00 % Common Equity Tier 1 (to risk-weighted assets) Consolidated 966,701 13.42 % 324,052 4.50 % N/A N/A Glacier Bank 1,041,640 14.50 % 323,245 4.50 % 466,910 6.50 % Tier 1 capital (to average assets) Consolidated 1,089,142 11.90 % 365,994 4.00 % N/A N/A Glacier Bank 1,041,640 11.45 % 363,945 4.00 % 454,932 5.00 % ______________________________ N/A - Not applicable

Stock-based Compensation Plan (

Stock-based Compensation Plan (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Activity for restricted stock awards	The following table summarizes the restricted stock award activity for the year ended December 31, 2017 : Restricted Stock Weighted- Average Grant Date Fair Value Non-vested at December 31, 2016 222,732 $ 24.46 Granted 104,836 36.59 Vested (141,864 ) 26.41 Forfeited (2,526 ) 29.07 Non-vested at December 31, 2017 183,178 29.84

Other Expenses (Tables)

Other Expenses (Tables)	12 Months Ended
	Dec. 31, 2017
Other Expenses [Abstract]
Schedule of Other Expenses	Other expenses consists of the following: Years ended (Dollars in thousands) December 31, December 31, December 31, Debit card expenses $ 7,189 8,462 6,153 Consulting and outside services 5,331 5,683 3,845 Employee expenses 4,160 3,573 2,425 Telephone 3,891 3,828 3,318 VIE amortization and other expenses 3,109 2,702 4,528 Loan expenses 3,080 3,611 2,824 Postage 2,684 2,785 3,716 Printing and supplies 2,661 2,800 3,529 Mergers and acquisition expenses 2,130 1,732 2,459 Business development 1,929 1,847 1,526 Accounting and audit fees 1,848 1,613 1,331 Checking and operating expenses 1,760 2,942 3,553 ATM expenses 1,720 880 1,082 Legal fees 1,106 1,027 866 Other 4,447 4,085 3,892 Total other expenses $ 47,045 47,570 45,047

Federal and State Income Taxes

Federal and State Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Summary of consolidated income tax expense	The following table is a summary of consolidated income tax expense: Years ended (Dollars in thousands) December 31, December 31, December 31, Current Federal $ 29,555 30,461 28,705 State 9,183 9,283 9,374 Total current income tax expense 38,738 39,744 38,079 Deferred 1 Federal 22,246 (70 ) (3,451 ) State 3,641 (12 ) (629 ) Total deferred income tax expense (benefit) 25,887 (82 ) (4,080 ) Total income tax expense $ 64,625 39,662 33,999 ______________________________ 1 Includes tax benefit of operating loss carryforwards of $644,000 , $571,000 and $391,000 for the years ended December 31, 2017 , 2016 , and 2015 , respectively.
Summary of effective tax rate	Combined federal and state income tax expense differs from that computed at the federal statutory corporate tax rate as follows: Years ended December 31, December 31, December 31, Federal statutory rate 35.0 % 35.0 % 35.0 % State taxes, net of federal income tax benefit 4.6 % 3.8 % 3.7 % Tax rate change 10.9 % — % — % Tax-exempt interest income (10.5 )% (12.2 )% (12.6 )% Tax credits (3.2 )% (2.1 )% (3.0 )% Other, net (1.1 )% 0.2 % (0.5 )% Effective tax rate 35.7 % 24.7 % 22.6 %
Summary of net deferred tax asset	The tax effect of temporary differences which give rise to a significant portion of deferred tax assets and deferred tax liabilities are as follows: (Dollars in thousands) December 31, December 31, Deferred tax assets Allowance for loan and lease losses $ 32,890 50,172 Deferred compensation 5,640 8,320 Other real estate owned 5,126 8,309 Acquisition fair market value adjustments 4,139 4,763 Net operating loss carryforwards 2,841 4,737 Employee benefits 2,615 3,927 Interest rate swap agreements 2,379 5,705 Other 3,673 5,569 Total gross deferred tax assets 59,303 91,502 Deferred tax liabilities Deferred loan costs (5,854 ) (8,061 ) Intangibles (4,161 ) (5,477 ) Depreciation of premises and equipment (2,863 ) (3,111 ) FHLB stock dividends (2,602 ) (3,976 ) Available-for-sale securities (1,707 ) (1,036 ) Debt modification costs (1,591 ) — Other (2,181 ) (2,720 ) Total gross deferred tax liabilities (20,959 ) (24,381 ) Net deferred tax asset $ 38,344 67,121
Income tax return jurisdictions and years subject to examination	The following schedule summarizes the years that remain subject to examination as of December 31, 2017 : Years ended December 31, Federal 2013, 2014, 2015 and 2016 Montana 2014, 2015 and 2016 Idaho 2014, 2015 and 2016 Utah 2014, 2015 and 2016 Colorado 2013, 2014, 2015 and 2016 Arizona 2013, 2014, 2015 and 2016

Accumulated Other Comprehensi46

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Activity within Accumulated Other Comprehensive Income (Loss), Net of Tax	The following table illustrates the activity within accumulated other comprehensive income (loss) by component, net of tax: (Dollars in thousands) Gains on Available-For-Sale Securities Losses on Derivatives Used for Cash Flow Hedges Total Balance at December 31, 2014 $ 27,945 (10,201 ) 17,744 Other comprehensive loss before reclassifications (13,968 ) (4,823 ) (18,791 ) Reclassification adjustments for (losses) gains included in net income (42 ) 3,078 3,036 Net current period other comprehensive loss (14,010 ) (1,745 ) (15,755 ) Balance at December 31, 2015 $ 13,935 (11,946 ) 1,989 Other comprehensive loss before reclassifications (13,113 ) (1,006 ) (14,119 ) Reclassification adjustments for gains included in net income 817 3,931 4,748 Net current period other comprehensive (loss) income (12,296 ) 2,925 (9,371 ) Balance at December 31, 2016 $ 1,639 (9,021 ) (7,382 ) Other comprehensive income before reclassifications 2,110 248 2,358 Reclassification adjustments for gains included in net income 391 3,005 3,396 Reclassifications from accumulated other comprehensive income (loss) to retained earnings 1 891 (1,242 ) (351 ) Net current period other comprehensive income 3,392 2,011 5,403 Balance at December 31, 2017 $ 5,031 (7,010 ) (1,979 ) ______________________________ 1 Reclassifications were due to the one-time revaluation of the deferred tax assets and deferred tax liabilities as a result of the Tax Act. For additional information relating to this reclassification, see Note 1.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Basic and diluted earnings per share	Basic and diluted earnings per share has been computed based on the following: Years ended (Dollars in thousands, except per share data) December 31, December 31, December 31, Net income available to common stockholders, basic and diluted $ 116,377 121,131 116,127 Average outstanding shares - basic 77,537,664 76,278,463 75,542,455 Add: dilutive restricted stock awards 69,941 63,373 53,126 Average outstanding shares - diluted 77,607,605 76,341,836 75,595,581 Basic earnings per share $ 1.50 1.59 1.54 Diluted earnings per share $ 1.50 1.59 1.54

Parent Holding Company Inform48

Parent Holding Company Information (Condensed) (Tables)	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Statements of Financial Condition	Condensed Statements of Financial Condition (Dollars in thousands) December 31, December 31, Assets Cash on hand and in banks $ 9,304 5,906 Interest bearing cash deposits 38,420 57,700 Cash and cash equivalents 47,724 63,606 Investment securities, available-for-sale — 36 Other assets 8,871 10,764 Investment in subsidiaries 1,281,392 1,201,667 Total assets $ 1,337,987 1,276,073 Liabilities and Stockholders’ Equity Dividends payable $ 265 23,137 Subordinated debentures 126,135 125,991 Other liabilities 12,530 10,076 Total liabilities 138,930 159,204 Common stock 780 765 Paid-in capital 797,997 749,107 Retained earnings 402,259 374,379 Accumulated other comprehensive loss (1,979 ) (7,382 ) Total stockholders’ equity 1,199,057 1,116,869 Total liabilities and stockholders’ equity $ 1,337,987 1,276,073
Condensed Statements of Operations and Comprehensive Income	Condensed Statements of Operations and Comprehensive Income Years ended (Dollars in thousands) December 31, December 31, December 31, Income Dividends from subsidiaries $ 119,000 108,350 109,000 Gain on sale of investments 3 — — Intercompany charges for services 14,299 12,248 10,562 Other income 225 311 196 Total income 133,527 120,909 119,758 Expenses Compensation and employee benefits 17,864 15,665 13,205 Other operating expenses 10,425 7,701 7,313 Total expenses 28,289 23,366 20,518 Income before income tax benefit and equity in undistributed net income of subsidiaries 105,238 97,543 99,240 Income tax benefit 2,983 4,040 3,105 Income before equity in undistributed net income of subsidiaries 108,221 101,583 102,345 Equity in undistributed net income of subsidiaries 8,156 19,548 13,782 Net Income $ 116,377 121,131 116,127 Comprehensive Income $ 122,131 111,760 100,372
Condensed Statements of Cash Flows	Condensed Statements of Cash Flows Years ended (Dollars in thousands) December 31, December 31, December 31, Operating Activities Net income $ 116,377 121,131 116,127 Adjustments to reconcile net income to net cash provided by operating activities: Subsidiary income in excess of dividends distributed (8,156 ) (19,548 ) (13,782 ) Amortization of purchase accounting adjustments 143 143 143 Gain on sale of investments (3 ) — — Stock-based compensation, net of tax benefits 1,460 804 695 Net change in other assets and other liabilities 5,051 (297 ) 118 Net cash provided by operating activities 114,872 102,233 103,301 Investing Activities Sales of available-for-sale securities 27 — — Net (increase) decrease of premises and equipment (79 ) 771 (1,405 ) Proceeds from sale of non-marketable equity securities 114 55 22 Equity contributions to subsidiaries (17,565 ) (3,475 ) (28,457 ) Net cash used in by investing activities (17,503 ) (2,649 ) (29,840 ) Financing Activities Cash dividends paid (111,720 ) (84,040 ) (79,456 ) Tax withholding payments for stock-based compensation (1,531 ) (600 ) (489 ) Net cash used in financing activities (113,251 ) (84,640 ) (79,945 ) Net (decrease) increase in cash and cash equivalents (15,882 ) 14,944 (6,484 ) Cash and cash equivalents at beginning of year 63,606 48,662 55,146 Cash and cash equivalents at end of year $ 47,724 63,606 48,662

Unaudited Quarterly Financial49

Unaudited Quarterly Financial Data (Condensed) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Summarized unaudited quarterly financial data	Summarized unaudited quarterly financial data is as follows: Quarters ended 2017 (Dollars in thousands, except per share data) March 31 June 30 September 30 December 31 Interest income $ 87,628 94,032 96,464 96,898 Interest expense 7,366 7,774 7,652 7,072 Net interest income 80,262 86,258 88,812 89,826 Provision for loan losses 1,598 3,013 3,327 2,886 Net interest income after provision for loan losses 78,664 83,245 85,485 86,940 Non-interest income 25,689 27,656 31,185 27,709 Non-interest expense 63,344 65,309 68,552 68,366 Income before income taxes 41,009 45,592 48,118 46,283 Federal and state income tax expense 9,754 11,905 11,639 31,327 Net income $ 31,255 33,687 36,479 14,956 Basic earnings per share $ 0.41 0.43 0.47 0.19 Diluted earnings per share $ 0.41 0.43 0.47 0.19 Quarters ended 2016 (Dollars in thousands, except per share data) March 31 June 30 September 30 December 31 Interest income $ 84,381 86,069 85,944 87,759 Interest expense 7,675 7,424 7,318 7,214 Net interest income 76,706 78,645 78,626 80,545 Provision for loan losses 568 — 626 1,139 Net interest income after provision for loan losses 76,138 78,645 78,000 79,406 Non-interest income 24,252 26,759 28,293 28,014 Non-interest expense 62,356 64,461 65,180 66,717 Income before income taxes 38,034 40,943 41,113 40,703 Federal and state income tax expense 9,352 10,492 10,156 9,662 Net income $ 28,682 30,451 30,957 31,041 Basic earnings per share $ 0.38 0.40 0.40 0.41 Diluted earnings per share $ 0.38 0.40 0.40 0.41

Fair Value of Assets and Liab50

Fair Value of Assets and Liabilities (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair value measurement of assets and liabilities measured at fair value on a recurring basis	The following tables disclose the fair value measurement of assets and liabilities measured at fair value on a recurring basis: Fair Value Measurements At the End of the Reporting Period Using (Dollars in thousands) Fair Value December 31, 2017 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Investment securities, available-for-sale U.S. government and federal agency $ 31,127 — 31,127 — U.S. government sponsored enterprises 19,091 — 19,091 — State and local governments 629,501 — 629,501 — Corporate bonds 216,762 — 216,762 — Residential mortgage-backed securities 779,283 — 779,283 — Commercial mortgage-backed securities 102,479 — 102,479 — Loans held for sale 38,833 — 38,833 — Total assets measured at fair value on a recurring basis $ 1,817,076 — 1,817,076 — Interest rate swaps $ 9,389 — 9,389 — Total liabilities measured at fair value on a recurring basis $ 9,389 — 9,389 — Note 20. Fair Value of Assets and Liabilities (continued) Fair Value Measurements At the End of the Reporting Period Using (Dollars in thousands) Fair Value December 31, 2016 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Investment securities, available-for-sale U.S. government and federal agency $ 39,407 — 39,407 — U.S. government sponsored enterprises 19,570 — 19,570 — State and local governments 786,373 — 786,373 — Corporate bonds 471,951 — 471,951 — Residential mortgage-backed securities 1,007,515 — 1,007,515 — Commercial mortgage-backed securities 100,661 — 100,661 — Total assets measured at fair value on a recurring basis $ 2,425,477 — 2,425,477 — Interest rate swaps $ 14,725 — 14,725 — Total liabilities measured at fair value on a recurring basis $ 14,725 — 14,725 —
Fair value measurement of assets measured at fair value on a non-recurring basis	The following tables disclose the fair value measurement of assets with a recorded change during the period resulting from re-measuring the assets at fair value on a non-recurring basis: Fair Value Measurements At the End of the Reporting Period Using (Dollars in thousands) Fair Value December 31, 2017 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Other real estate owned $ 2,296 — — 2,296 Collateral-dependent impaired loans, net of ALLL 6,339 — — 6,339 Total assets measured at fair value on a non-recurring basis $ 8,635 — — 8,635 Fair Value Measurements At the End of the Reporting Period Using (Dollars in thousands) Fair Value December 31, 2016 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Other real estate owned $ 7,839 — — 7,839 Collateral-dependent impaired loans, net of ALLL 5,664 — — 5,664 Total assets measured at fair value on a non-recurring basis $ 13,503 — — 13,503
Quantitative information about assets measured at fair value on a non-recurring basis for which Level 3 inputs were used	The following tables present additional quantitative information about assets measured at fair value on a non-recurring basis and for which the Company has utilized Level 3 inputs to determine fair value: Fair Value Quantitative Information about Level 3 Fair Value Measurements (Dollars in thousands) December 31, Valuation Technique Unobservable Input Range (Weighted- Average) 1 Other real estate owned $ 2,296 Sales comparison approach Selling costs 0.0% - 10.0% (6.0%) Collateral-dependent impaired loans, net of ALLL $ 238 Cost approach Selling costs 10.0% - 20.0% (10.6%) 2,541 Sales comparison approach Selling costs 8.0% - 10.0% (9.4%) 3,560 Combined approach Selling costs 10.0% - 10.0% (10.0%) $ 6,339 Note 20. Fair Value of Assets and Liabilities (continued) Fair Value Quantitative Information about Level 3 Fair Value Measurements (Dollars in thousands) December 31, Valuation Technique Unobservable Input Range (Weighted- Average) 1 Other real estate owned $ 7,767 Sales comparison approach Selling costs 6.0% - 10.0% (6.9%) Adjustment to comparables 0.0% - 10.0% (0.1%) 72 Combined approach Selling costs 10.0% - 10.0% (10.0%) Adjustment to comparables 10.0% - 10.0% (10.0%) $ 7,839 Collateral-dependent impaired loans, net of ALLL $ 110 Cost approach Selling costs 6.0% - 20.0% (6.6%) 1,982 Sales comparison approach Selling costs 8.0% - 10.0% (9.6%) 3,572 Combined approach Selling costs 10.0% - 10.0% (10.0%) Adjustment to comparables 20.0% - 20.0% (20.0%) $ 5,664 ______________________________ 1 The range for selling costs and adjustments to comparables indicate reductions to the fair value.
Carrying amounts and estimated fair values of financial instruments	The following tables present the carrying amounts, estimated fair values and the level within the fair value hierarchy of the Company’s financial instruments: Fair Value Measurements At the End of the Reporting Period Using (Dollars in thousands) Carrying Amount December 31, 2017 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial assets Cash and cash equivalents $ 200,004 200,004 — — Investment securities, available-for-sale 1,778,243 — 1,778,243 — Investment securities, held-to-maturity 648,313 — 660,086 — Loans held for sale 38,833 — 38,833 — Loans receivable, net of ALLL 6,448,256 — 6,219,515 114,771 Accrued interest receivable 44,462 44,462 — — Non-marketable equity securities 29,884 — 29,884 — Total financial assets $ 9,187,995 244,466 8,726,561 114,771 Financial liabilities Deposits $ 7,579,747 6,602,445 978,803 — FHLB advances 353,995 — 352,886 — Repurchase agreements and other borrowed funds 370,797 — 370,797 — Subordinated debentures 126,135 — 98,023 — Accrued interest payable 3,450 3,450 — — Interest rate swaps 9,389 — 9,389 — Total financial liabilities $ 8,443,513 6,605,895 1,809,898 — Note 20. Fair Value of Assets and Liabilities (continued) Fair Value Measurements At the End of the Reporting Period Using (Dollars in thousands) Carrying Amount December 31, 2016 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial assets Cash and cash equivalents $ 152,541 152,541 — — Investment securities, available-for-sale 2,425,477 — 2,425,477 — Investment securities, held-to-maturity 675,674 — 689,089 — Loans held for sale 72,927 72,927 — — Loans receivable, net of ALLL 5,554,891 — 5,380,286 123,382 Accrued interest receivable 45,832 45,832 — — Non-marketable equity securities 25,550 — 25,550 — Total financial assets $ 8,952,892 271,300 8,520,402 123,382 Financial liabilities Deposits $ 7,372,279 6,090,879 1,283,532 — FHLB advances 251,749 — 257,643 — Repurchase agreements and other borrowed funds 478,090 — 478,090 — Subordinated debentures 125,991 — 85,557 — Accrued interest payable 3,584 3,584 — — Interest rate swaps 14,725 — 14,725 — Total financial liabilities $ 8,246,418 6,094,463 2,119,547 —

Contingencies and Commitments (

Contingencies and Commitments (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Outstanding commitments	The Company had the following outstanding commitments: (Dollars in thousands) December 31, December 31, Unused lines of credit $ 1,565,112 1,325,236 Letters of credit 40,082 26,162 Total outstanding commitments $ 1,605,194 1,351,398

Mergers and Acquisitions (Table

Mergers and Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Consideration transferred, identifiable net assets acquired and resulting goodwill	The following table discloses the calculation of the fair value of the consideration transferred, the total identifiable net assets acquired and the resulting goodwill arising from the Foothills and TSB acquisitions: Foothills TSB (Dollars in thousands) April 30, August 31, Fair value of consideration transferred Fair value of Company shares issued, net of equity issuance costs $ 46,673 10,465 Cash consideration for outstanding shares 17,342 3,475 Contingent consideration — — Total fair value of consideration transferred 64,015 13,940 Recognized amounts of identifiable assets acquired and liabilities assumed Identifiable assets acquired Cash and cash equivalents 13,251 10,176 Investment securities 25,420 — Loans receivable 292,529 51,875 Core deposit intangible 1 4,331 762 Accrued income and other assets 19,699 6,937 Total identifiable assets acquired 355,230 69,750 Liabilities assumed Deposits 296,760 58,364 FHLB advances 22,800 3,260 Accrued expenses and other liabilities 2,264 601 Total liabilities assumed 321,824 62,225 Total identifiable net assets 33,406 7,525 Goodwill recognized $ 30,609 6,415 ______________________________ 1 The core deposit intangible for each acquisition was determined to have an estimated life of 10 years .
Unaudited Pro Forma Summary of the Company as if the Acquisitions had Occurred at the Beginning of the Period	The following unaudited pro forma summary presents consolidated information of the Company as if the Foothills acquisition had occurred on January 1, 2016: Years ended (Dollars in thousands) December 31, December 31, Net interest income and non-interest income $ 462,603 436,678 Net income 114,187 124,373 Total income consisting of net interest income and non-interest income of the acquired operations of TSB was approximately $1,800,000 and net income was approximately $897,000 from August 31, 2016 to December 31, 2016. The following unaudited pro forma summary presents consolidated information of the Company as if the TSB acquisition had occurred on January 1, 2015: Years ended (Dollars in thousands) December 31, December 31, Net interest income and non-interest income $ 424,242 392,252 Net income 120,929 116,577

Nature of Operations and Summ53

Nature of Operations and Summary of Significant Accounting Policies (Details Textual)	12 Months Ended
	Dec. 31, 2017USD ($)quarterstepoperating_segmentdivisionreporting_unit$ / shares	Dec. 31, 2016USD ($)
Number of Bank Divisions | division	14
Number of Operating Segments | operating_segment	1
Total assets	$ 9,706,349,000	$ 9,450,600,000
Gross loans	$ 6,577,824,000	5,684,463,000
Maximum Period of Original Maturity to be Included in Cash and Cash Equivalents	3 months
Federal Reserve Balance or Cash on Hand Required	$ 10,916,000
Minimum Period Past Due to Consider Loans as Delinquent	30 days
Minimum Period Past Due to Consider Loans as Non Accrual	90 days
Number of Quarters Used to Evaluate Historical Loss Experience | quarter	12
Maximum period up to which purchase price of business is allocated to assets acquired and liabilities assumed	1 year
Number of Reporting Units Subsequent to Aggregation for Goodwill Assessment | reporting_unit	1
Number of steps included in goodwill impairment test | step	2
Bank Owned Life Insurance	$ 59,351,000	$ 50,451,000
Percentage of likelihood for term more likely than not as it relates to income taxes	50.00%
Federal Tax Rate Subsequent to Enactment of The Tax Cuts and Jobs Act	21.00%
Period to begin developing and implementing processes and procedures for FASB Accounting Standards Update 2016-13	2 years
Maximum lease term to not recognize lease assets and liabilities	12 months
Number of Steps to Achieve Core Revenue Recognition Principal | step	5
Accounting Standards Update 2018-02
Reclassifications from accumulated other comprehensive income (loss) to retained earnings	$ 351,000
Accounting Standards Update 2016-09
Effect of change on net income from applying new accounting pronouncement	$ 553,000
Effect of change on diluted earnings per share from applying new accounting pronouncement | $ / shares	$ 0.01
Accounting Standards Update 2017-08
Effect of cumulative change on retained earnings from applying new accounting pronouncement	$ 21,219,000
Interest Rate Lock Commitments
Off-balance Sheet Commitments	$ 67,861,000
Consumer and Other
Minimum Number of Days Delinquent to Charge Off Loans	120 days
Minimum Range
Number of years for home equity loan origination term	10 years
Minimum Range | Office Buildings
Useful life of premises and equipment	15 years
Minimum Range | Furniture, fixtures and equipment
Useful life of premises and equipment	3 years
Maximum Range
Number of years for home equity loan origination term	15 years
Maximum Range | Office Buildings
Useful life of premises and equipment	40 years
Maximum Range | Furniture, fixtures and equipment
Useful life of premises and equipment	10 years
Collegiate Peaks Bank
Total assets	$ 532,958,000
Gross loans	345,687,000
Total deposits	463,970,000
First Security Bank
Total assets	1,027,685,000
Gross loans	639,880,000
Total deposits	$ 891,390,000

Amortized Cost, Gross Unrealize

Amortized Cost, Gross Unrealized Gains and Losses and Fair Value of Investment Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Available-for-sale
Amortized Cost	$ 1,771,504	$ 2,422,802
Gross Unrealized Gains	22,433	24,960
Gross Unrealized Losses	(15,694)	(22,285)
Fair Value	1,778,243	2,425,477
Held-to-maturity
Amortized Cost	648,313	675,674
Gross Unrealized Gains	20,346	21,400
Gross Unrealized Losses	(8,573)	(7,985)
Fair Value	660,086	689,089
Total
Amortized Cost	2,419,817	3,098,476
Gross Unrealized Gains	42,779	46,360
Gross Unrealized Losses	24,267	30,270
Fair Value	2,438,329	3,114,566
U.S. government and federal agency
Available-for-sale
Amortized Cost	31,216	39,554
Gross Unrealized Gains	54	15
Gross Unrealized Losses	(143)	(162)
Fair Value	31,127	39,407
U.S. government sponsored enterprises
Available-for-sale
Amortized Cost	19,195	19,557
Gross Unrealized Gains	0	55
Gross Unrealized Losses	(104)	(42)
Fair Value	19,091	19,570
State and local governments
Available-for-sale
Amortized Cost	614,366	775,395
Gross Unrealized Gains	20,299	20,941
Gross Unrealized Losses	(5,164)	(9,963)
Fair Value	629,501	786,373
Held-to-maturity
Amortized Cost	648,313	675,674
Gross Unrealized Gains	20,346	21,400
Gross Unrealized Losses	(8,573)	(7,985)
Fair Value	660,086	689,089
Corporate bonds
Available-for-sale
Amortized Cost	216,443	471,569
Gross Unrealized Gains	802	1,175
Gross Unrealized Losses	(483)	(793)
Fair Value	216,762	471,951
Residential mortgage backed securities
Available-for-sale
Amortized Cost	785,960	1,014,518
Gross Unrealized Gains	1,253	2,744
Gross Unrealized Losses	(7,930)	(9,747)
Fair Value	779,283	1,007,515
Commercial mortgage backed securities
Available-for-sale
Amortized Cost	104,324	102,209
Gross Unrealized Gains	25	30
Gross Unrealized Losses	(1,870)	(1,578)
Fair Value	$ 102,479	$ 100,661

Investment Securities Investmen

Investment Securities Investment Securities Maturity Schedule (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Available-for-Sale, Amortized Cost
Due within one year		$ 69,596
Due after one year through five years		228,415
Due after five years through ten years		228,766
Due after ten years		354,443
Total before mortgage-backed securities		881,220
Total		1,771,504	$ 2,422,802
Available-for-Sale, Fair Value
Due with one year		69,650
Due after one year through five years		228,881
Due after five years through ten years		236,318
Due after ten years		361,632
Total before mortgage-backed securities		896,481
Total		1,778,243	2,425,477
Held-to-Maturity, Amortized Cost
Due within one year		0
Due after one year through five years		2,108
Due after five years through ten years		86,741
Due after ten years		559,464
Total before mortgage-backed securities		648,313
Amortized Cost		648,313	675,674
Held-to-Maturity, Fair Value
Due within one year		0
Due after one year through five years		2,136
Due after five years through ten years		88,264
Due after ten years		569,686
Total before mortgage-backed securities		660,086
Total		660,086	$ 689,089
Mortgage-backed securities
Available-for-Sale, Amortized Cost
Mortgage-backed securities	[1]	890,284
Available-for-Sale, Fair Value
Mortgage-backed securities	[1]	881,762
Held-to-Maturity, Amortized Cost
Mortgage-backed securities	[1]	0
Held-to-Maturity, Fair Value
Mortgage-backed securities	[1]	$ 0
[1]	Mortgage-backed securities, which have prepayment provisions, are not assigned to maturity categories due to fluctuations in their prepayment speeds.

Gain or Loss on Sale of Investm

Gain or Loss on Sale of Investments (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Available-for-sale
Proceeds from sales and calls of investment securities		$ 280,783	$ 212,140	$ 167,660
Gross realized gains	[1]	3,369	2,459	1,877
Gross realized losses	[1]	(4,005)	(3,794)	(1,808)
Held-to-maturity
Proceeds from calls of investment securities		23,020	25,405	20,997
Gross realized gains	[1]	204	97	50
Gross realized losses	[1]	$ (228)	$ (225)	$ (100)
[1]	The gain or loss on the sale or call of each investment security is determined by the specific identification method.

Investments with an Unrealized

Investments with an Unrealized Loss Position (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Available-for-sale, Fair Value
Less than 12 Months	$ 586,721	$ 1,188,397
12 Months or More	484,508	144,120
Total	1,071,229	1,332,517
Available-for-sale, Unrealized Loss
Less than 12 Months	(4,533)	(16,446)
12 Months or Longer	(11,161)	(5,839)
Total	(15,694)	(22,285)
Held-to-maturity, Fair Value
Less than 12 Months	21,207	117,912
12 Months or More	105,486	86,601
Total	126,693	204,513
Held-to-maturity, Unrealized Loss
Less than 12 Months	(186)	(1,712)
12 Months or More	(8,387)	(6,273)
Total	(8,573)	(7,985)
U.S. government and federal agency
Available-for-sale, Fair Value
Less than 12 Months	1,208	6,718
12 Months or More	13,179	26,239
Total	14,387	32,957
Available-for-sale, Unrealized Loss
Less than 12 Months	(5)	(24)
12 Months or Longer	(138)	(138)
Total	(143)	(162)
U.S. government sponsored enterprises
Available-for-sale, Fair Value
Less than 12 Months	14,926	6,049
12 Months or More	3,425	0
Total	18,351	6,049
Available-for-sale, Unrealized Loss
Less than 12 Months	(56)	(42)
12 Months or Longer	(48)	0
Total	(104)	(42)
State and local governments
Available-for-sale, Fair Value
Less than 12 Months	61,126	222,700
12 Months or More	121,181	81,783
Total	182,307	304,483
Available-for-sale, Unrealized Loss
Less than 12 Months	(689)	(4,949)
12 Months or Longer	(4,475)	(5,014)
Total	(5,164)	(9,963)
Held-to-maturity, Fair Value
Less than 12 Months	21,207	117,912
12 Months or More	105,486	86,601
Total	126,693	204,513
Held-to-maturity, Unrealized Loss
Less than 12 Months	(186)	(1,712)
12 Months or More	(8,387)	(6,273)
Total	(8,573)	(7,985)
Corporate bonds
Available-for-sale, Fair Value
Less than 12 Months	99,636	174,821
12 Months or More	29,034	6,141
Total	128,670	180,962
Available-for-sale, Unrealized Loss
Less than 12 Months	(264)	(774)
12 Months or Longer	(219)	(19)
Total	(483)	(793)
Residential mortgage backed securities
Available-for-sale, Fair Value
Less than 12 Months	372,175	688,811
12 Months or More	254,721	29,957
Total	626,896	718,768
Available-for-sale, Unrealized Loss
Less than 12 Months	(3,050)	(9,079)
12 Months or Longer	(4,880)	(668)
Total	(7,930)	(9,747)
Commercial mortgage backed securities
Available-for-sale, Fair Value
Less than 12 Months	37,650	89,298
12 Months or More	62,968	0
Total	100,618	89,298
Available-for-sale, Unrealized Loss
Less than 12 Months	(469)	(1,578)
12 Months or Longer	(1,401)	0
Total	$ (1,870)	$ (1,578)

Investment Securities (Details

Investment Securities (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Investment securities pledged as collateral	$ 1,447,808,000	$ 1,878,739,000
Other-than-temporary impairment on investment securities	$ 0	$ 0

Loans Receivable, Net Summary o

Loans Receivable, Net Summary of Loans Receivable (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Summary of Loans Receivable
Loans receivable	$ 6,577,824	$ 5,684,463
Allowance for loan and lease losses	(129,568)	(129,572)
Loans receivable, net	6,448,256	5,554,891
Net deferred origination (fees) costs included in loans receivable	(2,643)	(1,228)
Net purchase accounting (discounts) premiums included in loans receivable	$ (16,325)	$ (12,144)
Weighted-average interest rate on loans (tax-equivalent)	4.81%	4.77%
Residential Real Estate | Residential Real Estate
Summary of Loans Receivable
Loans receivable	$ 720,728	$ 674,347
Allowance for loan and lease losses	(10,798)	(12,436)
Commercial
Summary of Loans Receivable
Loans receivable	5,156,492	4,332,391
Commercial | Commercial Real Estate
Summary of Loans Receivable
Loans receivable	3,577,139	2,990,141
Allowance for loan and lease losses	(68,515)	(65,773)
Commercial | Other Commercial
Summary of Loans Receivable
Loans receivable	1,579,353	1,342,250
Allowance for loan and lease losses	(39,303)	(37,823)
Consumer and Other
Summary of Loans Receivable
Loans receivable	700,604	677,725
Consumer and Other | Home Equity
Summary of Loans Receivable
Loans receivable	457,918	434,774
Allowance for loan and lease losses	(6,204)	(7,572)
Consumer and Other | Other Consumer
Summary of Loans Receivable
Loans receivable	242,686	242,951
Allowance for loan and lease losses	$ (4,748)	$ (5,968)

ALLL Activity (Details)

ALLL Activity (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for loan and lease losses
Balance at beginning of period				$ 129,572				$ 129,697	$ 129,572	$ 129,697	$ 129,753
Provision for loan losses	$ 2,886	$ 3,327	$ 3,013	1,598	$ 1,139	$ 626	$ 0	568	10,824	2,333	2,284
Charge-offs									(19,331)	(11,496)	(7,002)
Recoveries									8,503	9,038	4,662
Balance at end of period	129,568				129,572				129,568	129,572	129,697
Residential Real Estate | Residential Real Estate
Allowance for loan and lease losses
Balance at beginning of period				12,436				14,427	12,436	14,427	14,680
Provision for loan losses									(1,521)	(1,734)	640
Charge-offs									(199)	(464)	(985)
Recoveries									82	207	92
Balance at end of period	10,798				12,436				10,798	12,436	14,427
Commercial | Commercial Real Estate
Allowance for loan and lease losses
Balance at beginning of period				65,773				67,877	65,773	67,877	67,799
Provision for loan losses									7,152	(2,686)	(696)
Charge-offs									(6,188)	(3,082)	(1,920)
Recoveries									1,778	3,664	2,694
Balance at end of period	68,515				65,773				68,515	65,773	67,877
Commercial | Other Commercial
Allowance for loan and lease losses
Balance at beginning of period				37,823				32,525	37,823	32,525	30,891
Provision for loan losses									2,545	5,164	3,030
Charge-offs									(2,856)	(1,778)	(2,322)
Recoveries									1,791	1,912	926
Balance at end of period	39,303				37,823				39,303	37,823	32,525
Consumer and Other | Home Equity
Allowance for loan and lease losses
Balance at beginning of period				7,572				8,998	7,572	8,998	9,963
Provision for loan losses									(1,103)	(520)	(480)
Charge-offs									(489)	(1,185)	(809)
Recoveries									224	279	324
Balance at end of period	6,204				7,572				6,204	7,572	8,998
Consumer and Other | Other Consumer
Allowance for loan and lease losses
Balance at beginning of period				$ 5,968				$ 5,870	5,968	5,870	6,420
Provision for loan losses									3,751	2,109	(210)
Charge-offs									(9,599)	(4,987)	(966)
Recoveries									4,628	2,976	626
Balance at end of period	$ 4,748				$ 5,968				$ 4,748	$ 5,968	$ 5,870

Loans Receivable, Net ALLL and

Loans Receivable, Net ALLL and Loans Receivable Summary (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Loans Receivable and Allowance for Loan and Lease Losses
Individually evaluated for impairment	$ 119,994	$ 130,263
Collectively evaluated for impairment	6,457,830	5,554,200
Total loans receivable	6,577,824	5,684,463
Individually evaluated for impairment	5,223	6,881
Collectively evaluated for impairment	124,345	122,691
Total allowance for loan and lease losses	129,568	129,572
Residential Real Estate | Residential Real Estate
Loans Receivable and Allowance for Loan and Lease Losses
Individually evaluated for impairment	12,399	11,612
Collectively evaluated for impairment	708,329	662,735
Total loans receivable	720,728	674,347
Individually evaluated for impairment	246	856
Collectively evaluated for impairment	10,552	11,580
Total allowance for loan and lease losses	10,798	12,436
Commercial
Loans Receivable and Allowance for Loan and Lease Losses
Total loans receivable	5,156,492	4,332,391
Commercial | Commercial Real Estate
Loans Receivable and Allowance for Loan and Lease Losses
Individually evaluated for impairment	77,536	85,634
Collectively evaluated for impairment	3,499,603	2,904,507
Total loans receivable	3,577,139	2,990,141
Individually evaluated for impairment	500	922
Collectively evaluated for impairment	68,015	64,851
Total allowance for loan and lease losses	68,515	65,773
Commercial | Other Commercial
Loans Receivable and Allowance for Loan and Lease Losses
Individually evaluated for impairment	23,032	23,950
Collectively evaluated for impairment	1,556,321	1,318,300
Total loans receivable	1,579,353	1,342,250
Individually evaluated for impairment	3,851	4,419
Collectively evaluated for impairment	35,452	33,404
Total allowance for loan and lease losses	39,303	37,823
Consumer and Other
Loans Receivable and Allowance for Loan and Lease Losses
Total loans receivable	700,604	677,725
Consumer and Other | Home Equity
Loans Receivable and Allowance for Loan and Lease Losses
Individually evaluated for impairment	3,755	5,934
Collectively evaluated for impairment	454,163	428,840
Total loans receivable	457,918	434,774
Individually evaluated for impairment	56	296
Collectively evaluated for impairment	6,148	7,276
Total allowance for loan and lease losses	6,204	7,572
Consumer and Other | Other Consumer
Loans Receivable and Allowance for Loan and Lease Losses
Individually evaluated for impairment	3,272	3,133
Collectively evaluated for impairment	239,414	239,818
Total loans receivable	242,686	242,951
Individually evaluated for impairment	570	388
Collectively evaluated for impairment	4,178	5,580
Total allowance for loan and lease losses	$ 4,748	$ 5,968

Impaired Loans (Details)

Impaired Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Summary of the impaired loans by portfolio class of loans
Loans with a Specific Valuation Allowance, Recorded Balance	$ 17,689	$ 22,128
Loans with a Specific Valuation Allowance, Unpaid Principal Balance	18,400	22,374
Specific valuation allowance	5,223	6,881
Loans with a Specific Valuation Allowance, Average Balance	18,986	26,745
Loans without a Specific Valuation Allowance, Recorded Balance	102,305	108,135
Loans without a Specific Valuation Allowance, Unpaid Principal Balance	122,833	131,059
Loans without a Specific Valuation Allowance, Average Balance	107,945	108,827
Recorded balance	119,994	130,263
Unpaid principal balance	141,233	153,433
Average balance	126,931	135,572
Residential Real Estate | Residential Real Estate
Summary of the impaired loans by portfolio class of loans
Loans with a Specific Valuation Allowance, Recorded Balance	2,978	2,759
Loans with a Specific Valuation Allowance, Unpaid Principal Balance	3,046	2,825
Specific valuation allowance	246	856
Loans with a Specific Valuation Allowance, Average Balance	2,928	4,942
Loans without a Specific Valuation Allowance, Recorded Balance	9,421	8,853
Loans without a Specific Valuation Allowance, Unpaid Principal Balance	10,380	9,925
Loans without a Specific Valuation Allowance, Average Balance	9,834	12,858
Recorded balance	12,399	11,612
Unpaid principal balance	13,426	12,750
Average balance	12,762	17,800
Commercial | Commercial Real Estate
Summary of the impaired loans by portfolio class of loans
Loans with a Specific Valuation Allowance, Recorded Balance	4,545	9,129
Loans with a Specific Valuation Allowance, Unpaid Principal Balance	4,573	9,130
Specific valuation allowance	500	922
Loans with a Specific Valuation Allowance, Average Balance	5,851	10,441
Loans without a Specific Valuation Allowance, Recorded Balance	72,991	76,505
Loans without a Specific Valuation Allowance, Unpaid Principal Balance	89,839	94,180
Loans without a Specific Valuation Allowance, Average Balance	76,427	72,323
Recorded balance	77,536	85,634
Unpaid principal balance	94,412	103,310
Average balance	82,278	82,764
Commercial | Other Commercial
Summary of the impaired loans by portfolio class of loans
Loans with a Specific Valuation Allowance, Recorded Balance	8,183	8,814
Loans with a Specific Valuation Allowance, Unpaid Principal Balance	8,378	8,929
Specific valuation allowance	3,851	4,419
Loans with a Specific Valuation Allowance, Average Balance	8,477	9,840
Loans without a Specific Valuation Allowance, Recorded Balance	14,849	15,136
Loans without a Specific Valuation Allowance, Unpaid Principal Balance	16,931	17,724
Loans without a Specific Valuation Allowance, Average Balance	15,129	15,537
Recorded balance	23,032	23,950
Unpaid principal balance	25,309	26,653
Average balance	23,606	25,377
Consumer and Other | Home Equity
Summary of the impaired loans by portfolio class of loans
Loans with a Specific Valuation Allowance, Recorded Balance	186	334
Loans with a Specific Valuation Allowance, Unpaid Principal Balance	199	345
Specific valuation allowance	56	296
Loans with a Specific Valuation Allowance, Average Balance	359	257
Loans without a Specific Valuation Allowance, Recorded Balance	3,569	5,600
Loans without a Specific Valuation Allowance, Unpaid Principal Balance	4,098	7,120
Loans without a Specific Valuation Allowance, Average Balance	4,734	6,004
Recorded balance	3,755	5,934
Unpaid principal balance	4,297	7,465
Average balance	5,093	6,261
Consumer and Other | Other Consumer
Summary of the impaired loans by portfolio class of loans
Loans with a Specific Valuation Allowance, Recorded Balance	1,797	1,092
Loans with a Specific Valuation Allowance, Unpaid Principal Balance	2,204	1,145
Specific valuation allowance	570	388
Loans with a Specific Valuation Allowance, Average Balance	1,371	1,265
Loans without a Specific Valuation Allowance, Recorded Balance	1,475	2,041
Loans without a Specific Valuation Allowance, Unpaid Principal Balance	1,585	2,110
Loans without a Specific Valuation Allowance, Average Balance	1,821	2,105
Recorded balance	3,272	3,133
Unpaid principal balance	3,789	3,255
Average balance	$ 3,192	$ 3,370

Loans Receivable Aging Analysis

Loans Receivable Aging Analysis (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Loan portfolio aging analysis
Non-accrual loans	$ 44,833	$ 49,332
Total past due and non-accrual loans	88,597	76,048
Current loans receivable	6,489,227	5,608,415
Total loans receivable	6,577,824	5,684,463
Accruing loans 30 to 59 days past due
Loan portfolio aging analysis
Past due loans	26,375	20,599
Accruing loans 60 to 89 days past due
Loan portfolio aging analysis
Past due loans	11,312	5,018
Accruing loans 90 days or more past due
Loan portfolio aging analysis
Past due loans	6,077	1,099
Residential Real Estate | Residential Real Estate
Loan portfolio aging analysis
Non-accrual loans	4,924	4,528
Total past due and non-accrual loans	14,336	12,530
Current loans receivable	706,392	661,817
Total loans receivable	720,728	674,347
Residential Real Estate | Residential Real Estate | Accruing loans 30 to 59 days past due
Loan portfolio aging analysis
Past due loans	6,252	6,338
Residential Real Estate | Residential Real Estate | Accruing loans 60 to 89 days past due
Loan portfolio aging analysis
Past due loans	794	1,398
Residential Real Estate | Residential Real Estate | Accruing loans 90 days or more past due
Loan portfolio aging analysis
Past due loans	2,366	266
Commercial
Loan portfolio aging analysis
Total loans receivable	5,156,492	4,332,391
Commercial | Commercial Real Estate
Loan portfolio aging analysis
Non-accrual loans	27,331	30,216
Total past due and non-accrual loans	45,853	36,194
Current loans receivable	3,531,286	2,953,947
Total loans receivable	3,577,139	2,990,141
Commercial | Commercial Real Estate | Accruing loans 30 to 59 days past due
Loan portfolio aging analysis
Past due loans	12,546	5,079
Commercial | Commercial Real Estate | Accruing loans 60 to 89 days past due
Loan portfolio aging analysis
Past due loans	5,367	754
Commercial | Commercial Real Estate | Accruing loans 90 days or more past due
Loan portfolio aging analysis
Past due loans	609	145
Commercial | Other Commercial
Loan portfolio aging analysis
Non-accrual loans	8,298	8,817
Total past due and non-accrual loans	18,407	15,840
Current loans receivable	1,560,946	1,326,410
Total loans receivable	1,579,353	1,342,250
Commercial | Other Commercial | Accruing loans 30 to 59 days past due
Loan portfolio aging analysis
Past due loans	3,634	5,388
Commercial | Other Commercial | Accruing loans 60 to 89 days past due
Loan portfolio aging analysis
Past due loans	3,502	1,352
Commercial | Other Commercial | Accruing loans 90 days or more past due
Loan portfolio aging analysis
Past due loans	2,973	283
Consumer and Other
Loan portfolio aging analysis
Total loans receivable	700,604	677,725
Consumer and Other | Home Equity
Loan portfolio aging analysis
Non-accrual loans	3,338	5,240
Total past due and non-accrual loans	6,467	8,714
Current loans receivable	451,451	426,060
Total loans receivable	457,918	434,774
Consumer and Other | Home Equity | Accruing loans 30 to 59 days past due
Loan portfolio aging analysis
Past due loans	2,142	2,439
Consumer and Other | Home Equity | Accruing loans 60 to 89 days past due
Loan portfolio aging analysis
Past due loans	987	844
Consumer and Other | Home Equity | Accruing loans 90 days or more past due
Loan portfolio aging analysis
Past due loans	0	191
Consumer and Other | Other Consumer
Loan portfolio aging analysis
Non-accrual loans	942	531
Total past due and non-accrual loans	3,534	2,770
Current loans receivable	239,152	240,181
Total loans receivable	242,686	242,951
Consumer and Other | Other Consumer | Accruing loans 30 to 59 days past due
Loan portfolio aging analysis
Past due loans	1,801	1,355
Consumer and Other | Other Consumer | Accruing loans 60 to 89 days past due
Loan portfolio aging analysis
Past due loans	662	670
Consumer and Other | Other Consumer | Accruing loans 90 days or more past due
Loan portfolio aging analysis
Past due loans	$ 129	$ 214

Troubled Debt Restructurings (D

Troubled Debt Restructurings (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)Loan	Dec. 31, 2016USD ($)Loan	Dec. 31, 2015USD ($)Loan
Troubled Debt Restructurings
Troubled Debt Restructurings, Number of Loans | Loan	32	34	64
Troubled Debt Restructurings, Pre-Modification Recorded Balance	$ 41,521	$ 22,907	$ 22,316
Troubled Debt Restructurings, Post-Modification Recorded Balance	$ 38,838	$ 22,848	$ 23,110
TDRs that Subsequently Defaulted, Number of Loans | Loan	1	1	7
TDRs that Subsequently Defaulted, Recorded Balance	$ 18	$ 6	$ 2,556
Residential Real Estate | Residential Real Estate
Troubled Debt Restructurings
Troubled Debt Restructurings, Number of Loans | Loan	5	0	3
Troubled Debt Restructurings, Pre-Modification Recorded Balance	$ 841	$ 0	$ 2,259
Troubled Debt Restructurings, Post-Modification Recorded Balance	$ 841	$ 0	$ 2,203
TDRs that Subsequently Defaulted, Number of Loans | Loan	0	0	1
TDRs that Subsequently Defaulted, Recorded Balance	$ 0	$ 0	$ 1,947
Commercial | Commercial Real Estate
Troubled Debt Restructurings
Troubled Debt Restructurings, Number of Loans | Loan	13	10	25
Troubled Debt Restructurings, Pre-Modification Recorded Balance	$ 31,109	$ 8,454	$ 8,877
Troubled Debt Restructurings, Post-Modification Recorded Balance	$ 28,426	$ 8,415	$ 9,927
TDRs that Subsequently Defaulted, Number of Loans | Loan	0	0	1
TDRs that Subsequently Defaulted, Recorded Balance	$ 0	$ 0	$ 78
Commercial | Other Commercial
Troubled Debt Restructurings
Troubled Debt Restructurings, Number of Loans | Loan	11	21	22
Troubled Debt Restructurings, Pre-Modification Recorded Balance	$ 9,403	$ 14,183	$ 10,545
Troubled Debt Restructurings, Post-Modification Recorded Balance	$ 9,403	$ 14,166	$ 10,325
TDRs that Subsequently Defaulted, Number of Loans | Loan	1	1	4
TDRs that Subsequently Defaulted, Recorded Balance	$ 18	$ 6	$ 529
Consumer and Other | Home Equity
Troubled Debt Restructurings
Troubled Debt Restructurings, Number of Loans | Loan	2	3	1
Troubled Debt Restructurings, Pre-Modification Recorded Balance	$ 158	$ 270	$ 137
Troubled Debt Restructurings, Post-Modification Recorded Balance	$ 158	$ 267	$ 157
TDRs that Subsequently Defaulted, Number of Loans | Loan	0	0	0
TDRs that Subsequently Defaulted, Recorded Balance	$ 0	$ 0	$ 0
Consumer and Other | Other Consumer
Troubled Debt Restructurings
Troubled Debt Restructurings, Number of Loans | Loan	1	0	13
Troubled Debt Restructurings, Pre-Modification Recorded Balance	$ 10	$ 0	$ 498
Troubled Debt Restructurings, Post-Modification Recorded Balance	$ 10	$ 0	$ 498
TDRs that Subsequently Defaulted, Number of Loans | Loan	0	0	1
TDRs that Subsequently Defaulted, Recorded Balance	$ 0	$ 0	$ 2

Loans Receivable, Net (Details

Loans Receivable, Net (Details Textual)	12 Months Ended
	Dec. 31, 2017USD ($)portfolio_segment	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Loans Receivable
Number of segments in the Company's loan portfolio | portfolio_segment	3
Percentage of consolidated stockholders equity exceeding which no borrower had outstanding loans or commitments	10.00%
Variable rate loans	$ 4,189,489,000
Fixed rate loans	2,388,335,000
Loans pledged as collateral	3,836,190,000
Aggregate amount of loans outstanding to related parties	82,350,000	$ 58,438,000
New loans to related parties	33,322,000
Repayments of loans by related parties	9,410,000
Interest income that would have been recorded on non-accrual loans	2,162,000	2,364,000	$ 2,471,000
TDR With Pre Modification Loan Balance for Which Oreo Was Received	5,987,000	5,331,000	8,893,000
Consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings are in process	743,000	1,770,000
OREO Secured by Residential Real Estate	893,000	2,699,000
Additional unfunded commitments on TDRs	1,960,000	4,785,000
Charge-offs on TDRs	$ 2,984,000	$ 557,000	$ 1,310,000

Premises and Equipment, Net of

Premises and Equipment, Net of Accumulated Depreciation (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Premises and Equipment, Net of Accumulated Depreciation
Accumulated depreciation	$ (127,876)	$ (119,748)
Premises and equipment, net	177,348	176,198
Land
Premises and Equipment, Net of Accumulated Depreciation
Premises and equipment, gross	31,370	29,648
Office buildings and construction in progress
Premises and Equipment, Net of Accumulated Depreciation
Premises and equipment, gross	182,592	173,886
Furniture, fixtures and equipment
Premises and Equipment, Net of Accumulated Depreciation
Premises and equipment, gross	83,177	84,559
Leasehold improvements
Premises and Equipment, Net of Accumulated Depreciation
Premises and equipment, gross	$ 8,085	$ 7,853

Premises and Equipment Future M

Premises and Equipment Future Minimum Rental Commitments under Operating and Capital Leases (Details) $ in Thousands	Dec. 31, 2017USD ($)
Capital Leases
For the Year Ended December 31, 2018	$ 92
For the Year Ended December 31, 2019	92
For the Year Ended December 31, 2020	92
For the Year Ended December 31, 2021	11
For the Year Ended December 31, 2022	0
Thereafter	0
Total minimum lease payments	287
Less: Amount representing interest	27
Present value of minimum lease payments	260
Less: Current portion of obligations under capital leases	79
Long-term portion of obligations under capital leases	181
Operating Leases
For the Year Ended December 31, 2018	2,633
For the Year Ended December 31, 2019	2,502
For the Year Ended December 31, 2020	2,039
For the Year Ended December 31, 2021	1,593
For the Year Ended December 31, 2022	953
Thereafter	5,541
Total Minimum Lease Payments	15,261
Total
For the Year Ended December 31, 2018	2,725
For the Year Ended December 31, 2019	2,594
For the Year Ended December 31, 2020	2,131
For the Year Ended December 31, 2021	1,604
For the Year Ended December 31, 2022	953
Thereafter	5,541
Total Minimum Lease Payments	$ 15,548

Premises and Equipment (Details

Premises and Equipment (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Premises and Equipment
Depreciation expense	$ 14,758,000	$ 15,294,000	$ 14,365,000
Total rent expense	3,629,000	3,255,000	3,137,000
Related party rent expense	$ 164,000	$ 153,000	$ 150,000

Net Carrying Value of Core Depo

Net Carrying Value of Core Deposit Intangibles (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net Core Deposit Intangibles and Aggregate Amortization Expense
Net carrying value	$ 14,184	$ 12,347
Aggregate amortization expense	2,494	2,970	$ 2,964
Core Deposits Intangibles
Net Core Deposit Intangibles and Aggregate Amortization Expense
Gross carrying value	21,649	21,943	38,527
Accumulated amortization	(7,465)	(9,596)	(23,972)
Net carrying value	14,184	12,347	14,555
Aggregate amortization expense	2,494	$ 2,970	$ 2,964
Estimated Amortization Expense
For the year ending December 31, 2018	2,209
For the year ending December 31, 2019	2,100
For the year ending December 31, 2020	2,027
For the year ending December 31, 2021	1,952
For the year ending December 31, 2022	$ 1,871

Changes in the Carrying Value o

Changes in the Carrying Value of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill Roll Forward
Net carrying value at beginning of period	$ 147,053	$ 140,638	$ 129,706
Acquisitions and adjustments	30,758	6,415	10,932
Net carrying value at end of period	$ 177,811	$ 147,053	$ 140,638

Other Intangible Assets and G71

Other Intangible Assets and Goodwill Other Intangible Assets and Goodwill (Details Textual) - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets
Accumulated impairment charge	$ 40,159,000	$ 40,159,000
Core Deposits Intangibles
Finite-Lived Intangible Assets
Core Deposit Intangibles Acquired	$ 4,331,000	$ 762,000	$ 6,619,000

Variable Interest Entities VIE

Variable Interest Entities VIE Carrying Amounts Included in Financial Statements (Details) - Consolidated VIEs - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Consolidated VIEs
Assets	$ 73,775	$ 47,094
Liabilities	8,063	4,134
Loans Receivable
Consolidated VIEs
Assets	57,796	36,950
Accrued Interest Receivable
Consolidated VIEs
Assets	94	120
Other Assets
Consolidated VIEs
Assets	15,885	10,024
Other Borrowed Funds
Consolidated VIEs
Liabilities	7,964	4,105
Accrued Interest Payable
Consolidated VIEs
Liabilities	1	2
Other Liabilities
Consolidated VIEs
Liabilities	$ 98	$ 27

Variable Interest Entities Amor

Variable Interest Entities Amortization Expense and Tax Credits and Other Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investments in Qualified Affordable Housing Projects
Amortization expense	$ 2,507	$ 1,125	$ 974
Tax credits and other tax benefits recognized	$ 3,827	$ 1,515	$ 1,552

Variable Interest Entities (Det

Variable Interest Entities (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Variable Interest Entities
Unfunded contingent commitments	$ 27,831,000
Year in which commitments will be fulfilled	2,018
Impairment losses	$ 0	$ 0	$ 0
Other assets
Variable Interest Entities
Carrying value of equity investments in LIHTCs	$ 9,169,000	$ 7,282,000
CDE
Variable Interest Entities
Tax credit period	7 years
LIHTC
Variable Interest Entities
Tax credit period	10 years
Tax credit compliance period	15 years

Scheduled Maturities of Time De

Scheduled Maturities of Time Deposits (Details) $ in Thousands	Dec. 31, 2017USD ($)
Maturities of Time Deposits
For the year ending December 31, 2018	$ 557,693
For the year ending December 31, 2019	120,657
For the year ending December 31, 2020	65,284
For the year ending December 31, 2021	45,409
For the year ending December 31, 2022	27,974
Thereafter	242
Total	$ 817,259

Deposits (Details Textual)

Deposits (Details Textual) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Deposits
FDIC Insurance limit	$ 250,000
Time deposits that meet or exceed FDIC Insurance limit	193,962,000	$ 254,611,000
Overdraft demand deposits reclassified as loans	4,402,000	3,618,000
Deposits with related parties	$ 25,641,000	$ 27,977,000

Borrowings Summary of Repurchas

Borrowings Summary of Repurchase Agreements (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Securities Sold Under Agreements to Repurchase
Repurchase Agreements	$ 362,573	$ 473,650
Overnight and Continuous
Securities Sold Under Agreements to Repurchase
Repurchase Agreements	362,573	473,007
Up to 30 Days
Securities Sold Under Agreements to Repurchase
Repurchase Agreements	0	643
Residential mortgage backed securities
Securities Sold Under Agreements to Repurchase
Repurchase Agreements	360,751	472,349
Residential mortgage backed securities | Overnight and Continuous
Securities Sold Under Agreements to Repurchase
Repurchase Agreements	360,751	471,706
Residential mortgage backed securities | Up to 30 Days
Securities Sold Under Agreements to Repurchase
Repurchase Agreements	0	643
Commercial mortgage backed securities
Securities Sold Under Agreements to Repurchase
Repurchase Agreements	1,822	1,301
Commercial mortgage backed securities | Overnight and Continuous
Securities Sold Under Agreements to Repurchase
Repurchase Agreements	1,822	1,301
Commercial mortgage backed securities | Up to 30 Days
Securities Sold Under Agreements to Repurchase
Repurchase Agreements	$ 0	$ 0

Scheduled Maturities of FHLB Ad

Scheduled Maturities of FHLB Advances (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
FHLB Advances
Maturing within one year, Amount	$ 200,869	$ 41,099
Maturing within one year, Weighted rate	1.64%	0.84%
Maturing one year through two years, Amount	$ 887	$ 70,983
Maturing one year through two years, Weighted rate	2.05%	1.42%
Maturing two years through three years, Amount	$ 1,651	$ 927
Maturing two years through three years, Weighted rate	3.58%	2.16%
Maturing three years through four years, Amount	$ 148,721	$ 1,728
Maturing three years through four years, Weighted rate	2.69%	3.66%
Maturing four years through five years, Amount	$ 945	$ 135,000
Maturing four years through five years, Weighted rate	5.25%	3.08%
Thereafter, Amount	$ 922	$ 2,012
Thereafter, Weighted rate	5.42%	5.33%
Total, Amount	$ 353,995	$ 251,749
Total, Weighted rate	2.11%	2.27%

Borrowings (Details Textual)

Borrowings (Details Textual) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Debt Disclosure [Abstract]
Repurchase Agreements	$ 362,573,000	$ 473,650,000
Securities Pledged for Repurchase Agreements	475,601,000	$ 472,239,000
Lines of credit	$ 230,000,000

Subordinated Debentures (Detail

Subordinated Debentures (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Terms of Subordinated Debentures
Balance	$ 126,135	$ 125,991
First Company Statutory Trust 2001
Terms of Subordinated Debentures
Balance	$ 3,269
Rate at December 31, 2017	4.68%
Variable Rate Structure	3 month LIBOR plus 3.30%
LIBOR Rate Spread	3.30%
Maturity Date	Jul. 31, 2031
First Company Statutory Trust 2003
Terms of Subordinated Debentures
Balance	$ 2,407
Rate at December 31, 2017	4.925%
Variable Rate Structure	3 month LIBOR plus 3.25%
LIBOR Rate Spread	3.25%
Maturity Date	Mar. 26, 2033
Glacier Capital Trust II
Terms of Subordinated Debentures
Balance	$ 46,393
Rate at December 31, 2017	4.109%
Variable Rate Structure	3 month LIBOR plus 2.75%
LIBOR Rate Spread	2.75%
Maturity Date	Apr. 7, 2034
Citizens (ID) Statutory Trust I
Terms of Subordinated Debentures
Balance	$ 5,155
Rate at December 31, 2017	4.25%
Variable Rate Structure	3 month LIBOR plus 2.65%
LIBOR Rate Spread	2.65%
Maturity Date	Jun. 17, 2034
Glacier Capital Trust III
Terms of Subordinated Debentures
Balance	$ 36,083
Rate at December 31, 2017	2.649%
Variable Rate Structure	3 month LIBOR plus 1.29%
LIBOR Rate Spread	1.29%
Maturity Date	Apr. 7, 2036
Glacier Capital Trust IV
Terms of Subordinated Debentures
Balance	$ 30,928
Rate at December 31, 2017	3.158%
Variable Rate Structure	3 month LIBOR plus 1.57%
LIBOR Rate Spread	1.57%
Maturity Date	Sep. 15, 2036
Bank of the San Juans Bancorporation Trust I
Terms of Subordinated Debentures
Balance	$ 1,900
Rate at December 31, 2017	3.301%
Variable Rate Structure	3 month LIBOR plus 1.82%
LIBOR Rate Spread	1.82%
Maturity Date	Mar. 1, 2037

Subordinated Debentures (Deta81

Subordinated Debentures (Details Textual)	12 Months Ended
	Dec. 31, 2017
Debt Instruments [Abstract]
Maximum Number of Consecutive Quarters for Deferral of Interest Payments on Trust Preferred Securities	20
Size of company eligible for Tier 1 grandfather provision	15,000,000,000

Interest Rate Swap Summary (Det

Interest Rate Swap Summary (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Interest Rate Swap One
Interest rate swap derivative financial instruments
Forecasted Notional Amount	$ 160,000
Variable Interest Rate	3 month LIBOR	[1]
Fixed Interest Rate	3.378%	[1]
Term, Effective Date	Oct. 21, 2014
Term, Maturity Date	Oct. 21, 2021
Interest Rate Swap Two
Interest rate swap derivative financial instruments
Forecasted Notional Amount	$ 100,000
Variable Interest Rate	3 month LIBOR	[1]
Fixed Interest Rate	2.498%	[1]
Term, Effective Date	Nov. 30, 2015
Term, Maturity Date	Nov. 30, 2022
[1]	The Company pays the fixed interest rate and the counterparty pays the Company the variable interest rate.

Derivatives and Hedging Activ83

Derivatives and Hedging Activities Interest Rate Swap Gains or Losses (Details) - Interest Rate Swap - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest Expense
Pre-Tax Gains or Losses
Amount of loss reclassified from OCI to interest expense	$ (4,892)	$ (6,417)	$ (5,025)
Other Non-Interest Expense
Pre-Tax Gains or Losses
Amount of loss recognized in other non-interest expense (ineffective portion)	0	0	0
Other Comprehensive Income
Pre-Tax Gains or Losses
Amount of gain (loss) recognized in OCI (effective portion)	$ 444	$ (1,643)	$ (7,857)

Derivatives and Hedging Activ84

Derivatives and Hedging Activities Offsetting Assets (Details) - Interest Rate Swap - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Offsetting Derivative Assets
Gross Amounts of Recognized Assets	$ 0	$ 0
Gross Amounts Offset in the Statements of Financial Position	0	0
Net Amounts of Assets Presented in the Statements of Financial Position	$ 0	$ 0

Derivatives and Hedging Activ85

Derivatives and Hedging Activities Offsetting Liabilities (Details) - Interest Rate Swap - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Offsetting Derivative Liabilities
Gross Amounts of Recognized Liabilities	$ 9,389	$ 14,725
Gross Amounts Offset in the Statements of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statements of Financial Position	$ 9,389	$ 14,725

Derivatives and Hedging Activ86

Derivatives and Hedging Activities Derivatives and Hedging Activities (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest rate swap derivative financial instruments
Investment securities pledged as collateral	$ 1,447,808,000	$ 1,878,739,000
Interest Rate Swap One
Interest rate swap derivative financial instruments
Forecasted Notional Amount	160,000,000
Interest Rate Swap Two
Interest rate swap derivative financial instruments
Forecasted Notional Amount	100,000,000
Interest Rate Swap
Interest rate swap derivative financial instruments
Interest rate expense recorded on interest rate swap	8,013,000	$ 8,035,000	$ 5,695,000
Unrealized loss to be reclassified within twelve months	4,228,000
Investment securities pledged as collateral	23,692,000
Collateral pledged from counterparties to the Company	$ 0

Regulatory Capital (Details)

Regulatory Capital (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Total capital (to risk-weighted assets)
Actual, Amount	$ 1,232,089	$ 1,179,673
Actual, Ratio	15.64%	16.38%
Minimum capital requirement, Amount	$ 630,109	$ 576,092
Minimum capital requirement, Ratio	8.00%	8.00%
Tier 1 capital (to risk-weighted assets)
Actual, Amount	$ 1,133,125	$ 1,089,142
Actual, Ratio	14.39%	15.12%
Minimum capital requirement, Amount	$ 472,582	$ 432,069
Minimum capital requirement, Ratio	6.00%	6.00%
Common Equity Tier 1 (to risk-weighted assets)
Actual, Amount	$ 1,009,276	$ 966,701
Actual, Ratio	12.81%	13.42%
Minimum capital requirement, Amount	$ 354,437	$ 324,052
Minimum capital requirement, Ratio	4.50%	4.50%
Tier 1 capital (to average assets)
Actual, Amount	$ 1,133,125	$ 1,089,142
Actual, Ratio	11.90%	11.90%
Minimum capital requirement, Amount	$ 380,770	$ 365,994
Minimum capital requirement, Ratio	4.00%	4.00%
Glacier Bank
Total capital (to risk-weighted assets)
Actual, Amount	$ 1,182,509	$ 1,131,949
Actual, Ratio	15.04%	15.76%
Minimum capital requirement, Amount	$ 628,823	$ 574,658
Minimum capital requirement, Ratio	8.00%	8.00%
Well capitalized requirement, Amount	$ 786,029	$ 718,323
Well capitalized requirement, Ratio	10.00%	10.00%
Tier 1 capital (to risk-weighted assets)
Actual, Amount	$ 1,083,744	$ 1,041,640
Actual, Ratio	13.79%	14.50%
Minimum capital requirement, Amount	$ 471,617	$ 430,994
Minimum capital requirement, Ratio	6.00%	6.00%
Well capitalized requirement, Amount	$ 628,823	$ 574,658
Well capitalized requirement, Ratio	8.00%	8.00%
Common Equity Tier 1 (to risk-weighted assets)
Actual, Amount	$ 1,083,744	$ 1,041,640
Actual, Ratio	13.79%	14.50%
Minimum capital requirement, Amount	$ 353,713	$ 323,245
Minimum capital requirement, Ratio	4.50%	4.50%
Well capitalized requirement, Amount	$ 510,919	$ 466,910
Well capitalized requirement, Ratio	6.50%	6.50%
Tier 1 capital (to average assets)
Actual, Amount	$ 1,083,744	$ 1,041,640
Actual, Ratio	11.47%	11.45%
Minimum capital requirement, Amount	$ 377,809	$ 363,945
Minimum capital requirement, Ratio	4.00%	4.00%
Well capitalized requirement, Amount	$ 472,261	$ 454,932
Well capitalized requirement, Ratio	5.00%	5.00%

Regulatory Capital (Details Tex

Regulatory Capital (Details Textual)	Dec. 31, 2017
Common Equity Tier 1 (to risk-weighted assets)
Capital Conservation Buffer for 2017	1.25%

Stock-based Compensation Plan S

Stock-based Compensation Plan Summary of Restricted Stock Award Activity (Details) - Restricted Stock	12 Months Ended
	Dec. 31, 2017$ / sharesshares
Restricted stock award activity for the year
Restricted Stock Non-Vested, Beginning Balance | shares	222,732
Restricted Stock, Granted | shares	104,836
Restricted Stock, Vested | shares	(141,864)
Restricted Stock, Forfeited | shares	(2,526)
Restricted Stock Non-Vested, Ending Balance | shares	183,178
Weighted-average grant date fair value
Restricted stock, weighted average grant date fair value, beginning balance | $ / shares	$ 24.46
Restricted stock, granted, weighted average grant date fair value | $ / shares	36.59
Restricted stock, vested, weighted average grant date fair value | $ / shares	26.41
Restricted stock, forfeited, weighted average grant date fair value | $ / shares	29.07
Restricted stock, weighted average grant date fair value, ending balance | $ / shares	$ 29.84

Stock-based Compensation Plan90

Stock-based Compensation Plan (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Stock-based Compensation Plans
Number of stock-based compensation plans	2
Shares available to grant to employees and directors	2,249,767
Restricted Stock
Restricted Stock Awards
Compensation expense related to awards	$ 3,764,000	$ 2,870,000	$ 2,470,000
Income tax benefit related to awards	1,452,000	1,112,000	957,000
Unrecognized compensation expense	$ 3,288,000
Unrecognized compensation expense, recognized over weighted-average period	1 year 9 months 18 days
Fair value of awards that vested	$ 3,746,000	2,624,000	1,761,000
Tax benefit of awards that vested	$ 1,998,000	$ 1,053,000	$ 795,000
Average remaining contractual term on non-vested awards	9 months 18 days
Aggregate intrinsic value of non-vested awards	$ 7,215,000

Employee Benefit Plans (Details

Employee Benefit Plans (Details Textual)	12 Months Ended
	Dec. 31, 2017USD ($)quarterhouryear	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
401(k) and Profit Sharing Plans
401(k) and Profit Sharing Plans
Minimum age required to be considered eligible for plan | year	21
Period of Employment Required to be Eligible for Plan	3 months
Minimum number of quarters required to be eligible for employer discretionary contribution | quarter	1
Minimum number of hours required to be considered eligible for employer discretionary contribution | hour	501
Percent rate for non-elective safe harbor contribution as component of profit sharing plan	3.00%
Profit Sharing Plan Expense	$ 10,100,000	$ 9,041,000	$ 8,017,000
Age of Employee | year	50
Percentage of amount out of first specific percent of employee's contribution matched under plan	50.00%
Percentage of employee's contribution required to determine the matched amount under the plan	6.00%
Company's contribution to the plan	$ 3,224,000	2,946,000	2,629,000
401(k) and Profit Sharing Plans | Age Under 50
401(k) and Profit Sharing Plans
Maximum percentage of annual compensation allowable for contribution by eligible employees	60.00%
401(k) and Profit Sharing Plans | Age 50 and Over
401(k) and Profit Sharing Plans
Maximum percentage of annual compensation allowable for contribution by eligible employees	100.00%
Deferred Compensation Plans
401(k) and Profit Sharing Plans
Percentage of salary for deferral of cash payments	50.00%
Percentage of bonuses and directors fees for deferral of cash payments	100.00%
Total amount deferred	$ 739,000	967,000	720,000
Credit earning rate as a percentage of return on equity	50.00%
Total earnings for the plan	$ 481,000	431,000	386,000
Liability related to obligations of deferred compensation plans	11,275,000	11,273,000
Supplemental Employee Retirement Plan
401(k) and Profit Sharing Plans
Company's contribution to the plan	$ 287,000	299,000	224,000
Credit earning rate as a percentage of return on equity	50.00%
Total earnings for the plan	$ 105,000	$ 85,000	$ 69,000

Other Expenses (Details)

Other Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Expenses
Debit card expenses	$ 7,189	$ 8,462	$ 6,153
Consulting and outside services	5,331	5,683	3,845
Employee expenses	4,160	3,573	2,425
Telephone	3,891	3,828	3,318
VIE amortization and other expenses	3,109	2,702	4,528
Loan expenses	3,080	3,611	2,824
Postage	2,684	2,785	3,716
Printing and supplies	2,661	2,800	3,529
Mergers and acquisition expenses	2,130	1,732	2,459
Business development	1,929	1,847	1,526
Accounting and audit fees	1,848	1,613	1,331
Checking and operating expenses	1,760	2,942	3,553
ATM expenses	1,720	880	1,082
Legal fees	1,106	1,027	866
Other	4,447	4,085	3,892
Total other expenses	$ 47,045	$ 47,570	$ 45,047

Summary of Income Tax Expense (

Summary of Income Tax Expense (Details) - USD ($)		3 Months Ended								12 Months Ended
		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current
Federal										$ 29,555,000	$ 30,461,000	$ 28,705,000
State										9,183,000	9,283,000	9,374,000
Total current income tax expense										38,738,000	39,744,000	38,079,000
Deferred
Federal	[1]									22,246,000	(70,000)	(3,451,000)
State	[1]									3,641,000	(12,000)	(629,000)
Total deferred income tax (benefit) expense	[1]									25,887,000	(82,000)	(4,080,000)
Total income tax expense		$ 31,327,000	$ 11,639,000	$ 11,905,000	$ 9,754,000	$ 9,662,000	$ 10,156,000	$ 10,492,000	$ 9,352,000	64,625,000	39,662,000	33,999,000
Tax benefit of operating loss carryforwards										$ 644,000	$ 571,000	$ 391,000
[1]	Includes tax benefit of operating loss carryforwards of $644,000, $571,000 and $391,000 for the years ended December 31, 2017, 2016, and 2015, respectively.

Summary of Effective Tax Rate (

Summary of Effective Tax Rate (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Effective income tax rate reconciliation
Federal statutory rate	35.00%	35.00%	35.00%
State taxes, net of federal income tax benefit	4.60%	3.80%	3.70%
Tax rate change	10.90%	0.00%	0.00%
Tax-exempt interest income	(10.50%)	(12.20%)	(12.60%)
Tax credits	(3.20%)	(2.10%)	(3.00%)
Other, net	(1.10%)	0.20%	(0.50%)
Effective tax rate	35.70%	24.70%	22.60%

Deferred Tax Assets and Deferre

Deferred Tax Assets and Deferred Tax Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets
Allowance for loan and lease losses	$ 32,890	$ 50,172
Deferred compensation	5,640	8,320
Other real estate owned	5,126	8,309
Acquisition fair market value adjustments	4,139	4,763
Net operating loss carryforwards	2,841	4,737
Employee benefits	2,615	3,927
Interest rate swap agreements	2,379	5,705
Other	3,673	5,569
Total gross deferred tax assets	59,303	91,502
Deferred tax liabilities
Deferred loan costs	(5,854)	(8,061)
Intangibles	(4,161)	(5,477)
Depreciation of premises and equipment	(2,863)	(3,111)
FHLB stock dividends	(2,602)	(3,976)
Available-for-sale securities	(1,707)	(1,036)
Debt modification costs	(1,591)	0
Other	(2,181)	(2,720)
Total gross deferred tax liabilities	(20,959)	(24,381)
Net deferred tax asset	$ 38,344	$ 67,121

Years Subject to Examination (D

Years Subject to Examination (Details)	12 Months Ended
	Dec. 31, 2017
Federal
Income Tax Examination
Income tax return jurisdictions and years that remain subject to examination	2013, 2014, 2015 and 2016
Montana
Income Tax Examination
Income tax return jurisdictions and years that remain subject to examination	2014, 2015 and 2016
Idaho
Income Tax Examination
Income tax return jurisdictions and years that remain subject to examination	2014, 2015 and 2016
Utah
Income Tax Examination
Income tax return jurisdictions and years that remain subject to examination	2014, 2015 and 2016
Colorado
Income Tax Examination
Income tax return jurisdictions and years that remain subject to examination	2013, 2014, 2015 and 2016
Arizona
Income Tax Examination
Income tax return jurisdictions and years that remain subject to examination	2013, 2014, 2015 and 2016

Federal and State Income Taxe97

Federal and State Income Taxes (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Tax Expense Information
Federal Tax Rate Prior to Enactment of The Tax Cuts and Jobs Act	35.00%
Federal Tax Rate Subsequent to Enactment of The Tax Cuts and Jobs Act	21.00%
Income Tax Expense Attributable to Decrease in Income Tax Rate	$ 19,699,000
Income Tax Uncertainties
Unrecognized income tax benefit	0	$ 0
Accrued liabilities for the payment of interest or penalties	0	0
Valuation Allowance
Deferred tax valuation allowance	0	$ 0
Federal
Operating Loss and Tax Credit Carryforwards
Operating Loss Carryforwards, Amount	10,635,000
Tax Credit Carryforward, Amount	$ 411,000
Federal | Earliest Tax Year
Operating Loss and Tax Credit Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2030
Federal | Latest Tax Year
Operating Loss and Tax Credit Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2035
Colorado
Operating Loss and Tax Credit Carryforwards
Operating Loss Carryforwards, Amount	$ 13,987,000
Colorado | Earliest Tax Year
Operating Loss and Tax Credit Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2031
Colorado | Latest Tax Year
Operating Loss and Tax Credit Carryforwards
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2032

Accumulated Other Comprehensi98

Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss)
Balance, beginning		$ (7,382)
Total other comprehensive income (loss), net of tax		5,754	$ (9,371)	$ (15,755)
Balance, end		(1,979)	(7,382)
Available-For-Sale Securities
Accumulated Other Comprehensive Income (Loss)
Balance, beginning		1,639	13,935	27,945
Other comprehensive income (loss) before reclassification		2,110	(13,113)	(13,968)
Reclassification adjustments for gains (losses) included in net income		391	817	(42)
Reclassifications from accumulated other comprehensive income (loss) to retained earnings	[1]	891
Total other comprehensive income (loss), net of tax		3,392	(12,296)	(14,010)
Balance, end		5,031	1,639	13,935
Derivatives Used for Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss)
Balance, beginning		(9,021)	(11,946)	(10,201)
Other comprehensive income (loss) before reclassification		248	(1,006)	(4,823)
Reclassification adjustments for gains (losses) included in net income		3,005	3,931	3,078
Reclassifications from accumulated other comprehensive income (loss) to retained earnings	[1]	(1,242)
Total other comprehensive income (loss), net of tax		2,011	2,925	(1,745)
Balance, end		(7,010)	(9,021)	(11,946)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss)
Balance, beginning		(7,382)	1,989	17,744
Other comprehensive income (loss) before reclassification		2,358	(14,119)	(18,791)
Reclassification adjustments for gains (losses) included in net income		3,396	4,748	3,036
Reclassifications from accumulated other comprehensive income (loss) to retained earnings	[1]	(351)
Total other comprehensive income (loss), net of tax		5,403	(9,371)	(15,755)
Balance, end		$ (1,979)	$ (7,382)	$ 1,989
[1]	Reclassifications were due to the one-time revaluation of the deferred tax assets and deferred tax liabilities as a result of the Tax Act. For additional information relating to this reclassification, see Note 1.

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Basic and Diluted Earnings Per Share
Net Income	$ 14,956	$ 36,479	$ 33,687	$ 31,255	$ 31,041	$ 30,957	$ 30,451	$ 28,682	$ 116,377	$ 121,131	$ 116,127
Average outstanding shares - basic									77,537,664	76,278,463	75,542,455
Add: dilutive restricted stock awards									69,941	63,373	53,126
Average outstanding shares - diluted									77,607,605	76,341,836	75,595,581
Basic earnings per share	$ 0.19	$ 0.47	$ 0.43	$ 0.41	$ 0.41	$ 0.40	$ 0.40	$ 0.38	$ 1.50	$ 1.59	$ 1.54
Diluted earnings per share	$ 0.19	$ 0.47	$ 0.43	$ 0.41	$ 0.41	$ 0.40	$ 0.40	$ 0.38	$ 1.50	$ 1.59	$ 1.54
Earnings Per Share
Restricted stock awards excluded from the diluted average outstanding share calculation									0	0	0

Condensed Statements of Financi

Condensed Statements of Financial Condition (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Assets
Cash on hand and in banks	$ 139,948	$ 135,268
Interest bearing cash deposits	60,056	17,273
Cash and cash equivalents	200,004	152,541
Investment securities, available-for-sale	1,778,243	2,425,477
Other assets	96,398	74,035
Total assets	9,706,349	9,450,600
Liabilities and Stockholders' Equity
Dividends payable	265	23,137	$ 22,893
Subordinated debentures	126,135	125,991
Other liabilities	73,168	102,038
Total liabilities	8,507,292	8,333,731
Common stock	780	765
Paid-in capital	797,997	749,107
Retained earnings	402,259	374,379
Accumulated other comprehensive loss	(1,979)	(7,382)
Total stockholders’ equity	1,199,057	1,116,869	$ 1,076,650	$ 1,028,047
Total liabilities and stockholders’ equity	9,706,349	9,450,600
Parent Company
Assets
Cash on hand and in banks	9,304	5,906
Interest bearing cash deposits	38,420	57,700
Cash and cash equivalents	47,724	63,606
Investment securities, available-for-sale	0	36
Other assets	8,871	10,764
Investment in subsidiaries	1,281,392	1,201,667
Total assets	1,337,987	1,276,073
Liabilities and Stockholders' Equity
Dividends payable	265	23,137
Subordinated debentures	126,135	125,991
Other liabilities	12,530	10,076
Total liabilities	138,930	159,204
Common stock	780	765
Paid-in capital	797,997	749,107
Retained earnings	402,259	374,379
Accumulated other comprehensive loss	(1,979)	(7,382)
Total stockholders’ equity	1,199,057	1,116,869
Total liabilities and stockholders’ equity	$ 1,337,987	$ 1,276,073

Condensed Statements of Operati

Condensed Statements of Operations and Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income
Gain on sale of investments									$ (660)	$ (1,463)	$ 19
Expenses
Compensation and employee benefits									160,506	151,697	134,382
Other operating expenses									47,045	47,570	45,047
Total expenses	$ 68,366	$ 68,552	$ 65,309	$ 63,344	$ 66,717	$ 65,180	$ 64,461	$ 62,356	265,571	258,714	236,757
Income tax benefit	(31,327)	(11,639)	(11,905)	(9,754)	(9,662)	(10,156)	(10,492)	(9,352)	(64,625)	(39,662)	(33,999)
Net Income	$ 14,956	$ 36,479	$ 33,687	$ 31,255	$ 31,041	$ 30,957	$ 30,451	$ 28,682	116,377	121,131	116,127
Comprehensive Income									122,131	111,760	100,372
Parent Company
Income
Dividends from subsidiaries									119,000	108,350	109,000
Gain on sale of investments									3	0	0
Intercompany charges for services									14,299	12,248	10,562
Other income									225	311	196
Total income									133,527	120,909	119,758
Expenses
Compensation and employee benefits									17,864	15,665	13,205
Other operating expenses									10,425	7,701	7,313
Total expenses									28,289	23,366	20,518
Income before income tax benefit and equity in undistributed net income of subsidiaries									105,238	97,543	99,240
Income tax benefit									2,983	4,040	3,105
Income before equity in undistributed net income of subsidiaries									108,221	101,583	102,345
Equity in undistributed net income of subsidiaries									8,156	19,548	13,782
Net Income									116,377	121,131	116,127
Comprehensive Income									$ 122,131	$ 111,760	$ 100,372

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Activities
Net income	$ 14,956	$ 36,479	$ 33,687	$ 31,255	$ 31,041	$ 30,957	$ 30,451	$ 28,682	$ 116,377	$ 121,131	$ 116,127
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of purchase accounting adjustments									(5,131)	(2,252)	1,264
Gain on sale of investments									660	1,463	(19)
Stock-based compensation, net of tax benefits									2,952	1,844	1,695
Net cash provided by operating activities									254,741	193,087	176,771
Investing Activities
Sales of available-for-sale securities									247,748	62,817	136,777
Net cash used in by investing activities									23,655	(421,313)	(681,314)
Financing Activities
Cash dividends paid									(111,720)	(84,040)	(79,456)
Tax withholding payments for stock-based compensation									(1,531)	(600)	(489)
Net cash used in financing activities									(230,933)	187,514	255,387
Net (decrease) increase in cash and cash equivalents									47,463	(40,712)	(249,156)
Cash and cash equivalents at beginning of period				152,541				193,253	152,541	193,253	442,409
Cash and cash equivalents at end of period	200,004				152,541				200,004	152,541	193,253
Parent Company
Operating Activities
Net income									116,377	121,131	116,127
Adjustments to reconcile net income to net cash provided by operating activities:
Subsidiary income in excess of dividends distributed									(8,156)	(19,548)	(13,782)
Amortization of purchase accounting adjustments									143	143	143
Gain on sale of investments									(3)	0	0
Stock-based compensation, net of tax benefits									1,460	804	695
Net change in other assets and other liabilities									5,051	(297)	118
Net cash provided by operating activities									114,872	102,233	103,301
Investing Activities
Sales of available-for-sale securities									27	0	0
Net (increase) decrease of premises and equipment									(79)	771	(1,405)
Proceeds from sale of non-marketable equity securities									114	55	22
Equity contribution to subsidiaries									(17,565)	(3,475)	(28,457)
Net cash used in by investing activities									(17,503)	(2,649)	(29,840)
Financing Activities
Cash dividends paid									(111,720)	(84,040)	(79,456)
Tax withholding payments for stock-based compensation									(1,531)	(600)	(489)
Net cash used in financing activities									(113,251)	(84,640)	(79,945)
Net (decrease) increase in cash and cash equivalents									(15,882)	14,944	(6,484)
Cash and cash equivalents at beginning of period				$ 63,606				$ 48,662	63,606	48,662	55,146
Cash and cash equivalents at end of period	$ 47,724				$ 63,606				$ 47,724	$ 63,606	$ 48,662

Unaudited Quarterly Financia103

Unaudited Quarterly Financial Data (Condensed) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Summarized unaudited quarterly financial data
Interest income	$ 96,898	$ 96,464	$ 94,032	$ 87,628	$ 87,759	$ 85,944	$ 86,069	$ 84,381	$ 375,022	$ 344,153	$ 319,681
Interest expense	7,072	7,652	7,774	7,366	7,214	7,318	7,424	7,675	29,864	29,631	29,275
Net interest income	89,826	88,812	86,258	80,262	80,545	78,626	78,645	76,706	345,158	314,522	290,406
Provision for loan losses	2,886	3,327	3,013	1,598	1,139	626	0	568	10,824	2,333	2,284
Net interest income after provision for loan losses	86,940	85,485	83,245	78,664	79,406	78,000	78,645	76,138	334,334	312,189	288,122
Non-interest income	27,709	31,185	27,656	25,689	28,014	28,293	26,759	24,252	112,239	107,318	98,761
Non-interest expense	68,366	68,552	65,309	63,344	66,717	65,180	64,461	62,356	265,571	258,714	236,757
Income before income taxes	46,283	48,118	45,592	41,009	40,703	41,113	40,943	38,034	181,002	160,793	150,126
Federal and state income tax expense	31,327	11,639	11,905	9,754	9,662	10,156	10,492	9,352	64,625	39,662	33,999
Net Income	$ 14,956	$ 36,479	$ 33,687	$ 31,255	$ 31,041	$ 30,957	$ 30,451	$ 28,682	$ 116,377	$ 121,131	$ 116,127
Basic earnings per share	$ 0.19	$ 0.47	$ 0.43	$ 0.41	$ 0.41	$ 0.40	$ 0.40	$ 0.38	$ 1.50	$ 1.59	$ 1.54
Diluted earnings per share	$ 0.19	$ 0.47	$ 0.43	$ 0.41	$ 0.41	$ 0.40	$ 0.40	$ 0.38	$ 1.50	$ 1.59	$ 1.54

Fair Value Measurements on a Re

Fair Value Measurements on a Recurring Basis (Details) - Recurring measurements - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financial Assets
Loans held-for-sale	$ 38,833
Total assets measured at fair value on a recurring basis	1,817,076	$ 2,425,477
Financial Liabilities
Total liabilities measured at fair value on a recurring basis	9,389	14,725
Interest rate swaps
Financial Liabilities
Interest rate swaps	9,389	14,725
U.S. government and federal agency
Financial Assets
Investment securities, available-for-sale	31,127	39,407
U.S. government sponsored enterprises
Financial Assets
Investment securities, available-for-sale	19,091	19,570
State and local governments
Financial Assets
Investment securities, available-for-sale	629,501	786,373
Corporate bonds
Financial Assets
Investment securities, available-for-sale	216,762	471,951
Residential mortgage backed securities
Financial Assets
Investment securities, available-for-sale	779,283	1,007,515
Commercial mortgage backed securities
Financial Assets
Investment securities, available-for-sale	102,479	100,661
Level 1
Financial Assets
Loans held-for-sale	0
Total assets measured at fair value on a recurring basis	0	0
Financial Liabilities
Total liabilities measured at fair value on a recurring basis	0	0
Level 1 | Interest rate swaps
Financial Liabilities
Interest rate swaps	0	0
Level 1 | U.S. government and federal agency
Financial Assets
Investment securities, available-for-sale	0	0
Level 1 | U.S. government sponsored enterprises
Financial Assets
Investment securities, available-for-sale	0	0
Level 1 | State and local governments
Financial Assets
Investment securities, available-for-sale	0	0
Level 1 | Corporate bonds
Financial Assets
Investment securities, available-for-sale	0	0
Level 1 | Residential mortgage backed securities
Financial Assets
Investment securities, available-for-sale	0	0
Level 1 | Commercial mortgage backed securities
Financial Assets
Investment securities, available-for-sale	0	0
Level 2
Financial Assets
Loans held-for-sale	38,833
Total assets measured at fair value on a recurring basis	1,817,076	2,425,477
Financial Liabilities
Total liabilities measured at fair value on a recurring basis	9,389	14,725
Level 2 | Interest rate swaps
Financial Liabilities
Interest rate swaps	9,389	14,725
Level 2 | U.S. government and federal agency
Financial Assets
Investment securities, available-for-sale	31,127	39,407
Level 2 | U.S. government sponsored enterprises
Financial Assets
Investment securities, available-for-sale	19,091	19,570
Level 2 | State and local governments
Financial Assets
Investment securities, available-for-sale	629,501	786,373
Level 2 | Corporate bonds
Financial Assets
Investment securities, available-for-sale	216,762	471,951
Level 2 | Residential mortgage backed securities
Financial Assets
Investment securities, available-for-sale	779,283	1,007,515
Level 2 | Commercial mortgage backed securities
Financial Assets
Investment securities, available-for-sale	102,479	100,661
Level 3
Financial Assets
Loans held-for-sale	0
Total assets measured at fair value on a recurring basis	0	0
Financial Liabilities
Total liabilities measured at fair value on a recurring basis	0	0
Level 3 | Interest rate swaps
Financial Liabilities
Interest rate swaps	0	0
Level 3 | U.S. government and federal agency
Financial Assets
Investment securities, available-for-sale	0	0
Level 3 | U.S. government sponsored enterprises
Financial Assets
Investment securities, available-for-sale	0	0
Level 3 | State and local governments
Financial Assets
Investment securities, available-for-sale	0	0
Level 3 | Corporate bonds
Financial Assets
Investment securities, available-for-sale	0	0
Level 3 | Residential mortgage backed securities
Financial Assets
Investment securities, available-for-sale	0	0
Level 3 | Commercial mortgage backed securities
Financial Assets
Investment securities, available-for-sale	$ 0	$ 0

Fair Value Measurements on a No

Fair Value Measurements on a Non-Recurring Basis (Details) - Nonrecurring Measurements - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets with a recorded change from re-measuring at fair value on a non-recurring basis
Other real estate owned	$ 2,296	$ 7,839
Collateral-dependent impaired loans, net of ALLL	6,339	5,664
Total assets measured at fair value on a non-recurring basis	8,635	13,503
Level 1
Assets with a recorded change from re-measuring at fair value on a non-recurring basis
Other real estate owned	0	0
Collateral-dependent impaired loans, net of ALLL	0	0
Total assets measured at fair value on a non-recurring basis	0	0
Level 2
Assets with a recorded change from re-measuring at fair value on a non-recurring basis
Other real estate owned	0	0
Collateral-dependent impaired loans, net of ALLL	0	0
Total assets measured at fair value on a non-recurring basis	0	0
Level 3
Assets with a recorded change from re-measuring at fair value on a non-recurring basis
Other real estate owned	2,296	7,839
Collateral-dependent impaired loans, net of ALLL	6,339	5,664
Total assets measured at fair value on a non-recurring basis	$ 8,635	$ 13,503

Fair Value of Assets and Lia106

Fair Value of Assets and Liabilities Quantitative Information about Level 3 Fair Value Measurements (Details) - Nonrecurring Measurements - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Quantitative Information About Level 3 Fair Value Measurements
Fair Value		$ 8,635	$ 13,503
Level 3
Quantitative Information About Level 3 Fair Value Measurements
Fair Value		8,635	13,503
Other real estate owned | Level 3
Quantitative Information About Level 3 Fair Value Measurements
Fair Value			7,839
Other real estate owned | Sales Comparison Approach | Level 3
Quantitative Information About Level 3 Fair Value Measurements
Fair Value		$ 2,296	7,767
Other real estate owned | Combined Approach | Level 3
Quantitative Information About Level 3 Fair Value Measurements
Fair Value			$ 72
Other real estate owned | Minimum Range | Sales Comparison Approach | Level 3
Unobservable Inputs
Selling Costs	[1]	0.00%	6.00%
Adjustment to Comparables	[1]		0.00%
Other real estate owned | Minimum Range | Combined Approach | Level 3
Unobservable Inputs
Selling Costs	[1]		10.00%
Adjustment to Comparables	[1]		10.00%
Other real estate owned | Maximum Range | Sales Comparison Approach | Level 3
Unobservable Inputs
Selling Costs	[1]	10.00%	10.00%
Adjustment to Comparables	[1]		10.00%
Other real estate owned | Maximum Range | Combined Approach | Level 3
Unobservable Inputs
Selling Costs	[1]		10.00%
Adjustment to Comparables	[1]		10.00%
Other real estate owned | Weighted Average Range | Sales Comparison Approach | Level 3
Unobservable Inputs
Selling Costs	[1]	6.00%	6.90%
Adjustment to Comparables	[1]		0.10%
Other real estate owned | Weighted Average Range | Combined Approach | Level 3
Unobservable Inputs
Selling Costs	[1]		10.00%
Adjustment to Comparables	[1]		10.00%
Collateral-dependent Impaired Loans, Net of ALLL | Level 3
Quantitative Information About Level 3 Fair Value Measurements
Fair Value		$ 6,339	$ 5,664
Collateral-dependent Impaired Loans, Net of ALLL | Sales Comparison Approach | Level 3
Quantitative Information About Level 3 Fair Value Measurements
Fair Value		2,541	1,982
Collateral-dependent Impaired Loans, Net of ALLL | Combined Approach | Level 3
Quantitative Information About Level 3 Fair Value Measurements
Fair Value		3,560	3,572
Collateral-dependent Impaired Loans, Net of ALLL | Cost Approach | Level 3
Quantitative Information About Level 3 Fair Value Measurements
Fair Value		$ 238	$ 110
Collateral-dependent Impaired Loans, Net of ALLL | Minimum Range | Sales Comparison Approach | Level 3
Unobservable Inputs
Selling Costs	[1]	8.00%	8.00%
Collateral-dependent Impaired Loans, Net of ALLL | Minimum Range | Combined Approach | Level 3
Unobservable Inputs
Selling Costs	[1]	10.00%	10.00%
Adjustment to Comparables	[1]		20.00%
Collateral-dependent Impaired Loans, Net of ALLL | Minimum Range | Cost Approach | Level 3
Unobservable Inputs
Selling Costs	[1]	10.00%	6.00%
Collateral-dependent Impaired Loans, Net of ALLL | Maximum Range | Sales Comparison Approach | Level 3
Unobservable Inputs
Selling Costs	[1]	10.00%	10.00%
Collateral-dependent Impaired Loans, Net of ALLL | Maximum Range | Combined Approach | Level 3
Unobservable Inputs
Selling Costs	[1]	10.00%	10.00%
Adjustment to Comparables	[1]		20.00%
Collateral-dependent Impaired Loans, Net of ALLL | Maximum Range | Cost Approach | Level 3
Unobservable Inputs
Selling Costs	[1]	20.00%	20.00%
Collateral-dependent Impaired Loans, Net of ALLL | Weighted Average Range | Sales Comparison Approach | Level 3
Unobservable Inputs
Selling Costs	[1]	9.40%	9.60%
Collateral-dependent Impaired Loans, Net of ALLL | Weighted Average Range | Combined Approach | Level 3
Unobservable Inputs
Selling Costs	[1]	10.00%	10.00%
Adjustment to Comparables	[1]		20.00%
Collateral-dependent Impaired Loans, Net of ALLL | Weighted Average Range | Cost Approach | Level 3
Unobservable Inputs
Selling Costs	[1]	10.60%	6.60%
[1]	The range for selling costs and adjustments to comparables indicate reductions to the fair value.

Carrying Amount and Fair Value

Carrying Amount and Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Carrying Amount
Financial Assets
Cash and cash equivalents	$ 200,004	$ 152,541
Investment securities, available-for-sale	1,778,243	2,425,477
Investment securities, held-to-maturity	648,313	675,674
Loans held-for-sale	38,833	72,927
Loans receivable, net of ALLL	6,448,256	5,554,891
Accrued interest receivable	44,462	45,832
Non-marketable equity securities	29,884	25,550
Total financial assets	9,187,995	8,952,892
Financial Liabilities
Deposits	7,579,747	7,372,279
FHLB advances	353,995	251,749
Repurchase agreements and other borrowed funds	370,797	478,090
Subordinated debentures	126,135	125,991
Accrued interest payable	3,450	3,584
Interest rate swaps	9,389	14,725
Total financial liabilities	8,443,513	8,246,418
Estimated Fair Value | Level 1
Financial Assets
Cash and cash equivalents	200,004	152,541
Investment securities, available-for-sale	0	0
Investment securities, held-to-maturity	0	0
Loans held-for-sale	0	72,927
Loans receivable, net of ALLL	0	0
Accrued interest receivable	44,462	45,832
Non-marketable equity securities	0	0
Total financial assets	244,466	271,300
Financial Liabilities
Deposits	6,602,445	6,090,879
FHLB advances	0	0
Repurchase agreements and other borrowed funds	0	0
Subordinated debentures	0	0
Accrued interest payable	3,450	3,584
Interest rate swaps	0	0
Total financial liabilities	6,605,895	6,094,463
Estimated Fair Value | Level 2
Financial Assets
Cash and cash equivalents	0	0
Investment securities, available-for-sale	1,778,243	2,425,477
Investment securities, held-to-maturity	660,086	689,089
Loans held-for-sale	38,833	0
Loans receivable, net of ALLL	6,219,515	5,380,286
Accrued interest receivable	0	0
Non-marketable equity securities	29,884	25,550
Total financial assets	8,726,561	8,520,402
Financial Liabilities
Deposits	978,803	1,283,532
FHLB advances	352,886	257,643
Repurchase agreements and other borrowed funds	370,797	478,090
Subordinated debentures	98,023	85,557
Accrued interest payable	0	0
Interest rate swaps	9,389	14,725
Total financial liabilities	1,809,898	2,119,547
Estimated Fair Value | Level 3
Financial Assets
Cash and cash equivalents	0	0
Investment securities, available-for-sale	0	0
Investment securities, held-to-maturity	0	0
Loans held-for-sale	0	0
Loans receivable, net of ALLL	114,771	123,382
Accrued interest receivable	0	0
Non-marketable equity securities	0	0
Total financial assets	114,771	123,382
Financial Liabilities
Deposits	0	0
FHLB advances	0	0
Repurchase agreements and other borrowed funds	0	0
Subordinated debentures	0	0
Accrued interest payable	0	0
Interest rate swaps	0	0
Total financial liabilities	$ 0	$ 0

Fair Value Measurements (Detail

Fair Value Measurements (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair value measurement transfers from one level to another	$ 0	$ 0	$ 0
Fair Value, Option, Changes in Fair Value, Gain (Loss)	$ 994,000	$ 0	$ 0

Contingencies and Commitment109

Contingencies and Commitments (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Outstanding Commitments
Outstanding commitments	$ 1,605,194	$ 1,351,398
Unused Lines of Credit
Outstanding Commitments
Outstanding commitments	1,565,112	1,325,236
Letters of Credit
Outstanding Commitments
Outstanding commitments	$ 40,082	$ 26,162

Consideration Transferred, Iden

Consideration Transferred, Identifiable Net Assets Acquired and Goodwill Recognized (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Liabilities assumed
Goodwill recognized		$ 30,758	$ 6,415	$ 10,932
The Foothills Bank
Fair value of consideration transferred
Fair value of Company shares issued, net of equity issuance costs		46,673
Cash consideration for outstanding shares		17,342
Contingent consideration		0
Total fair value of consideration transferred		64,015
Identifiable assets acquired
Cash and cash equivalents		13,251
Investment securities		25,420
Loans receivable		292,529
Core deposit intangible	[1]	4,331
Accrued income and other assets		19,699
Total identifiable assets acquired		355,230
Liabilities assumed
Deposits		296,760
FHLB advances		22,800
Accrued expenses and other liabilities		2,264
Total liabilities assumed		321,824
Total identifiable net assets		33,406
Goodwill recognized		$ 30,609
Core Deposit Intangible, Weighted Average Useful Life		10 years
Treasure State Bank
Fair value of consideration transferred
Fair value of Company shares issued, net of equity issuance costs			10,465
Cash consideration for outstanding shares			3,475
Contingent consideration			0
Total fair value of consideration transferred			13,940
Identifiable assets acquired
Cash and cash equivalents			10,176
Investment securities			0
Loans receivable			51,875
Core deposit intangible	[1]		762
Accrued income and other assets			6,937
Total identifiable assets acquired			69,750
Liabilities assumed
Deposits			58,364
FHLB advances			3,260
Accrued expenses and other liabilities			601
Total liabilities assumed			62,225
Total identifiable net assets			7,525
Goodwill recognized			$ 6,415
Core Deposit Intangible, Weighted Average Useful Life			10 years
[1]	The core deposit intangible for each acquisition was determined to have an estimated life of 10 years.

Pro Forma Summary (Details)

Pro Forma Summary (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
2017 acquisitions
Pro Forma Information
Net interest income and non-interest income	$ 462,603	$ 436,678
Net income	$ 114,187	124,373
2016 acquisitions
Pro Forma Information
Net interest income and non-interest income		424,242	$ 392,252
Net income		$ 120,929	$ 116,577

Mergers and Acquisitions (Detai

Mergers and Acquisitions (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
The Foothills Bank
Business Acquisition
Effective Date of Acquisition	Apr. 30, 2017
Percentage of Outstanding Common Stock Acquired	100.00%
Fair value of consideration transferred	$ 64,015,000
Number of Shares Issued for Aquisition	1,381,661
Cash consideration for outstanding shares	$ 17,342,000
Loans receivable	292,529,000
Loans Receivable Acquired, Gross Principal and Contractual Interest Due	303,527,000
Third-party Acquisition Related Costs	1,127,000
Net interest income and non-interest income	13,625,000
Net income	$ 2,626,000
Treasure State Bank
Business Acquisition
Effective Date of Acquisition		Aug. 31, 2016
Percentage of Outstanding Common Stock Acquired		100.00%
Fair value of consideration transferred		$ 13,940,000
Number of Shares Issued for Aquisition		349,545
Cash consideration for outstanding shares		$ 3,475,000
Loans receivable		51,875,000
Loans Receivable Acquired, Gross Principal and Contractual Interest Due		54,819,000
Third-party Acquisition Related Costs		456,000
Net interest income and non-interest income		1,800,000
Net income		$ 897,000

Subsequent Events (Details Text

Subsequent Events (Details Textual) - Acquisition of Collegiate Peaks Bank	Jan. 31, 2018USD ($)
Subsequent Event [Line Items]
Subsequent Event, Description	the Company acquired 100 percent of the outstanding common stock of Columbine Capital Corp., and its wholly-owned subsidiary, Collegiate Peaks Bank, a community bank based in Buena Vista, Colorado.
Percentage of Outstanding Common Stock Acquired	100.00%
Fair value of consideration transferred	$ 96,083,000