Glacier Bancorp (GBCI) 10-K 22 Feb 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Jan. 30, 2019	Jun. 30, 2018
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, 2018
Amendment Flag	false
Document Fiscal Year Focus	2,018
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 Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Public Float			$ 3,255,486,651
Entity Common Stock, Shares Outstanding		84,521,692

Consolidated Statements of Fina

Consolidated Statements of Financial Condition - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Assets
Cash on hand and in banks	$ 161,782	$ 139,948
Interest bearing cash deposits	42,008	60,056
Cash and cash equivalents	203,790	200,004
Debt securities, available-for-sale	2,571,663	1,778,243
Debt securities, held-to-maturity	297,915	648,313
Total debt securities	2,869,578	2,426,556
Loans held for sale, at fair value	33,156	38,833
Loans receivable	8,287,549	6,577,824
Allowance for loan and lease losses	(131,239)	(129,568)
Loans receivable, net	8,156,310	6,448,256
Premises and equipment, net	241,528	177,348
Other real estate owned	7,480	14,269
Accrued interest receivable	54,408	44,462
Deferred tax asset	23,564	38,344
Core deposit intangible, net	49,242	14,184
Goodwill	289,586	177,811
Non-marketable equity securities	27,871	29,884
Bank-owned life insurance	82,320	59,351
Other assets	76,651	37,047
Total assets	12,115,484	9,706,349
Liabilities
Non-interest bearing deposits	3,001,178	2,311,902
Interest bearing deposits	6,492,589	5,267,845
Securities sold under agreements to repurchase	396,151	362,573
Federal Home Loan Bank advances	440,175	353,995
Other borrowed funds	14,708	8,224
Subordinated debentures	134,051	126,135
Accrued interest payable	4,252	3,450
Other liabilities	116,526	73,168
Total liabilities	10,599,630	8,507,292
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	845	780
Paid-in capital	1,051,253	797,997
Retained earnings - substantially restricted	473,183	402,259
Accumulated other comprehensive loss	(9,427)	(1,979)
Total stockholders’ equity	1,515,854	1,199,057
Total liabilities and stockholders’ equity	$ 12,115,484	$ 9,706,349
Number of common stock shares issued and outstanding	84,521,692	78,006,956

Consolidated Statements of Fi_2

Consolidated Statements of Financial Condition (Parenthetical) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Preferred shares, par value	$ 0.01	$ 0.01
Preferred shares, authorized	1,000,000	1,000,000
Preferred shares, issued	0	0
Preferred shares, outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	117,187,500	117,187,500

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest Income
Investment securities	$ 86,499	$ 81,968	$ 90,392
Residential real estate loans	40,041	33,114	33,410
Commercial loans	304,164	227,356	188,949
Consumer and other loans	38,292	32,584	31,402
Total interest income	468,996	375,022	344,153
Interest Expense
Deposits	18,359	16,793	18,402
Securities sold under agreements to repurchase	2,248	1,858	1,207
Federal Home Loan Bank advances	8,880	6,748	6,221
Other borrowed funds	95	79	67
Subordinated debentures	5,949	4,386	3,734
Total interest expense	35,531	29,864	29,631
Net Interest Income	433,465	345,158	314,522
Provision for loan losses	9,953	10,824	2,333
Net interest income after provision for loan losses	423,512	334,334	312,189
Non-Interest Income
Service charges and other fees	74,887	67,717	62,405
Miscellaneous loan fees and charges	6,805	4,360	4,613
Gain on sale of loans	27,134	30,439	33,606
Loss on sale of debt securities	(1,113)	(660)	(1,463)
Other income	11,111	10,383	8,157
Total non-interest income	118,824	112,239	107,318
Non-Interest Expense
Compensation and employee benefits	195,056	160,506	151,697
Occupancy and equipment	30,734	26,631	25,979
Advertising and promotions	9,566	8,405	8,433
Data processing	15,911	14,150	14,390
Other real estate owned	3,221	1,909	2,895
Regulatory assessments and insurance	5,075	4,431	4,780
Core deposit intangible amortization	6,270	2,494	2,970
Other expense	54,294	47,045	47,570
Total non-interest expense	320,127	265,571	258,714
Income Before Income Taxes	222,209	181,002	160,793
Federal and state income tax expense	40,331	64,625	39,662
Net Income	$ 181,878	$ 116,377	$ 121,131
Basic earnings per share	$ 2.18	$ 1.50	$ 1.59
Diluted earnings per share	2.17	1.50	1.59
Dividends declared per share	$ 1.31	$ 1.14	$ 1.10
Average outstanding shares - basic	83,603,515	77,537,664	76,278,463
Average outstanding shares - diluted	83,677,185	77,607,605	76,341,836

Statements of Comprehensive Inc

Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net Income	$ 181,878	$ 116,377	$ 121,131
Other Comprehensive (Loss) Income, Net of Tax
Unrealized (losses) gains on available-for-sale securities	(15,608)	3,428	(21,407)
Reclassification adjustment for losses included in net income	12	636	1,335
Net unrealized (losses) gains on available-for-sale securities	(15,596)	4,064	(20,072)
Tax effect	3,952	(1,563)	7,776
Net of tax amount	(11,644)	2,501	(12,296)
Unrealized gains (losses) on derivatives used for cash flow hedges	3,286	444	(1,643)
Reclassification adjustment for losses included in net income	2,334	4,892	6,417
Net unrealized gains on derivatives used for cash flow hedges	5,620	5,336	4,774
Tax effect	(1,424)	(2,083)	(1,849)
Net of tax amount	4,196	3,253	2,925
Total other comprehensive (loss) income, net of tax	(7,448)	5,754	(9,371)
Total Comprehensive Income	$ 174,430	$ 122,131	$ 111,760

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, 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
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)
Net income	181,878			181,878
Other comprehensive income (loss)	(7,448)				(7,448)
Cash dividends declared	(110,954)			(110,954)
Stock issued in connection with acquisitions, shares		6,432,868
Stock issued in connection with acquisitions, amount	250,807	$ 64	250,743
Stock issuances under stock incentive plans, shares		81,868
Stock issuances under stock incentive plans, value	0	$ 1	(1)
Stock-based compensation and related taxes	$ 2,514		2,514
Balance, shares at Dec. 31, 2018	84,521,692	84,521,692
Balance at Dec. 31, 2018	$ 1,515,854	$ 845	$ 1,051,253	$ 473,183	$ (9,427)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash dividends declared per share	$ 1.31	$ 1.14	$ 1.10
Retained Earnings Substantially Restricted
Cash dividends declared per share	$ 1.31	$ 1.14	$ 1.10

Consolidated Statements of Cash

Consolidated Statements of Cash Flows	12 Months Ended
	Dec. 31, 2018USD ($)		Dec. 31, 2017USD ($)		Dec. 31, 2016USD ($)
Operating Activities
Net income	$ 181,878,000		$ 116,377,000		$ 121,131,000
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	9,953,000		10,824,000		2,333,000
Net amortization of debt securities	13,095,000		20,026,000		26,210,000
Net accretion of purchase accounting adjustments	(3,963,000)		(5,131,000)		(2,252,000)
Amortization of debt modification costs	1,649,000		471,000		0
Origination of loans held for sale	(841,451,000)		(889,212,000)		(1,098,864,000)
Proceeds from loans held for sale	896,145,000		984,506,000		1,155,186,000
Gain on sale of loans	(27,134,000)		(30,439,000)		(33,606,000)
Loss on sale of debt securities	1,113,000		660,000		1,463,000
Bank-owned life insurance income, net	(2,234,000)		(1,395,000)		(1,142,000)
Stock-based compensation expense, net of tax benefits	3,122,000		2,952,000		1,844,000
Depreciation of premises and equipment	16,019,000		14,758,000		15,294,000
Loss (gain) on sale and write-downs of other real estate owned, net	2,130,000		(1,641,000)		1,217,000
Deferred tax expense (benefit)	6,861,000	[1]	25,887,000	[1]	(82,000)	[1]
Core deposit intangible amortization	6,270,000		2,494,000		2,970,000
Amortization of investments in variable interest entities	7,639,000		4,692,000		2,578,000
Net (increase) decrease in accrued interest receivable	(2,741,000)		2,466,000		(1,144,000)
Net decrease in other assets	348,000		1,139,000		6,621,000
Net increase (decrease) in accrued interest payable	357,000		(135,000)		60,000
Net increase (decrease) in other liabilities	11,655,000		(4,558,000)		(6,730,000)
Net cash provided by operating activities	280,711,000		254,741,000		193,087,000
Investing Activities
Sales of available-for-sale debt securities	226,842,000		247,748,000		62,817,000
Maturities, prepayments and calls of available-for-sale debt securities	357,876,000		446,695,000		662,003,000
Purchases of available-for-sale debt securities	(820,333,000)		(36,239,000)		(585,064,000)
Maturities, prepayments and calls of held-to-maturity debt securities	76,832,000		25,187,000		25,405,000
Purchases of held-to-maturity debt securities	0		0		(1,222,000)
Principal collected on loans	2,691,953,000		2,099,292,000		1,781,534,000
Loan originations	(3,460,227,000)		(2,740,281,000)		(2,375,136,000)
Net additions to premises and equipment	(18,637,000)		(10,128,000)		(8,306,000)
Proceeds from sale of other real estate owned	9,385,000		12,335,000		10,145,000
Proceeds from redemption of non-marketable equity securities	87,221,000		68,610,000		73,611,000
Purchases of non-marketable equity securities	(87,975,000)		(71,396,000)		(67,594,000)
Proceeds from bank-owned life insurance	1,331,000		437,000		437,000
Investments in variable interest entities	(37,956,000)		(14,514,000)		(6,644,000)
Net cash received from (paid in) acquisitions	101,268,000		(4,091,000)		6,701,000
Net cash (used in) provided by investing activities	(872,420,000)		23,655,000		(421,313,000)
Financing Activities
Net increase (decrease) in deposits	599,037,000		(89,397,000)		368,006,000
Net increase (decrease) in securities sold under agreements to repurchase	4,398,000		(111,077,000)		50,236,000
Net increase (decrease) in short-term Federal Home Loan Bank advances	85,000,000		137,200,000		(100,000,000)
Proceeds from long-term Federal Home Loan Bank advances	0		150,000,000		0
Repayments of long-term Federal Home Loan Bank advances	(1,198,000)		(208,192,000)		(45,567,000)
Net (decrease) increase in other borrowed funds	(5,059,000)		3,784,000		(521,000)
Cash dividends paid	(85,493,000)		(111,720,000)		(84,040,000)
Tax withholding payments for stock-based compensation	(1,190,000)		(1,531,000)		(600,000)
Net cash provided by (used in) financing activities	595,495,000		(230,933,000)		187,514,000
Net increase (decrease) in cash, cash equivalents and restricted cash	3,786,000		47,463,000		(40,712,000)
Cash, cash equivalents and restricted cash at beginning of period	200,004,000		152,541,000		193,253,000
Cash, cash equivalents and restricted cash at end of period	203,790,000		200,004,000		152,541,000
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest	35,174,000		30,000,000		29,576,000
Cash paid during the period for income taxes	26,489,000		40,219,000		36,225,000
Supplemental Disclosure of Non-Cash Investing Activities
Transfer of debt securities from held-to-maturity to available-for-sale	270,331,000		0		0
Sale and refinancing of other real estate owned	406,000		553,000		728,000
Transfer of loans to other real estate owned	4,924,000		4,466,000		5,198,000
Dividends declared but not paid	25,726,000		265,000		23,137,000
Fair value of common stock shares issued	250,807,000		46,673,000		10,465,000
Cash consideration for outstanding shares	16,265,000		17,342,000		3,475,000
Effective settlement of pre-existing receivable	10,054,000		0		0
Fair value of assets acquired	1,660,882,000		355,230,000		69,750,000
Liabilities assumed	$ 1,383,756,000		$ 321,824,000		$ 62,225,000
[1]	Includes tax benefit of operating loss carryforwards of $443,000, $644,000 and $571,000 for the years ended December 31, 2018, 2017, and 2016, respectively.

Nature of Operations and Summar

Nature of Operations and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
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 debt 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 other assets on the Company's statements of financial condition. In February 2018, the Company completed its acquisition of Inter-Mountain Bancorp., Inc. and its wholly-owned subsidiary, First Security Bank, a community bank based in Bozeman, Montana (collectively, “FSB”). In January 2018, the Company completed its acquisition of Columbine Capital Corp., and its wholly-owned subsidiary, Collegiate Peaks Bank, a community bank based in Buena Vista, Colorado (collectively, “Collegiate”). 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, a community bank based in Missoula, Montana. The business combinations were accounted for using the acquisition method, with the results of operations 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. Note 1. Nature of Operations and Summary of Significant Accounting Policies (continued) 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, 2018 was $53,626,000 . Debt 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 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 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 debt 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 debt 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 debt 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 debt 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 debt 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 debt securities, see Note 2. Temporary versus Other-Than-Temporary Impairment The Company assesses individual debt securities in its investment portfolio for impairment at least on a quarterly basis, and more frequently when economic or market conditions warrant. A debt security 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 debt 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 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 other real estate owned (“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 to 40 years and the estimated useful life for furniture, fixtures, and equipment is 3 to 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 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, 2018 and 2017 , 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 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 r

Debt Securities

Debt Securities	12 Months Ended
	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Debt Securities	Debt Securities The following tables present the amortized cost, the gross unrealized gains and losses and the fair value of the Company’s debt securities: December 31, 2018 Amortized Cost Gross Unrealized Fair Value (Dollars in thousands) Gains Losses Available-for-sale U.S. government and federal agency $ 23,757 54 (162 ) 23,649 U.S. government sponsored enterprises 120,670 52 (514 ) 120,208 State and local governments 844,636 18,936 (11,322 ) 852,250 Corporate bonds 292,052 378 (1,613 ) 290,817 Residential mortgage-backed securities 808,537 628 (16,250 ) 792,915 Commercial mortgage-backed securities 490,868 3,312 (2,356 ) 491,824 Total available-for-sale 2,580,520 23,360 (32,217 ) 2,571,663 Held-to-maturity State and local governments 297,915 1,380 (11,039 ) 288,256 Total held-to-maturity 297,915 1,380 (11,039 ) 288,256 Total debt securities $ 2,878,435 24,740 (43,256 ) 2,859,919 Note 2. Debt Securities (continued) 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 debt securities $ 2,419,817 42,779 (24,267 ) 2,438,329 On November 30, 2018, the Company early adopted FASB ASU 2017-12, Derivatives and Hedging , and in doing so redesignated state and local government securities with a carrying value of $270,331,000 , from held-to-maturity classification to available-for-sale classification. The Company considers the available-for-sale classification of these debt securities to be appropriate since it no longer had the intent to hold them to maturity. No gain or loss was recorded at the time of transfer. For additional information on FASB ASU 2017-12, Derivatives and Hedging , see Note 1. The following table presents the amortized cost and fair value of available-for-sale and held-to-maturity debt securities by contractual maturity at December 31, 2018 . Actual maturities may differ from expected or contractual maturities since issuers have the right to prepay obligations with or without prepayment penalties. December 31, 2018 Available-for-Sale Held-to-Maturity (Dollars in thousands) Amortized Cost Fair Value Amortized Cost Fair Value Due within one year $ 141,771 141,356 — — Due after one year through five years 316,311 314,777 6,457 6,527 Due after five years through ten years 311,194 314,961 75,204 74,100 Due after ten years 511,839 515,830 216,254 207,629 1,281,115 1,286,924 297,915 288,256 Mortgage-backed securities 1 1,299,405 1,284,739 — — Total $ 2,580,520 2,571,663 297,915 288,256 ______________________________ 1 Mortgage-backed securities, which have prepayment provisions, are not assigned to maturity categories due to fluctuations in their prepayment speeds. Note 2. Debt Securities (continued) Proceeds from sales and calls of debt 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 debt securities $ 265,587 280,783 212,140 Gross realized gains 1 443 3,369 2,459 Gross realized losses 1 (455 ) (4,005 ) (3,794 ) Held-to-maturity Proceeds from calls of debt securities 79,000 23,020 25,405 Gross realized gains 1 101 204 97 Gross realized losses 1 (1,202 ) (228 ) (225 ) ______________________________ 1 The gain or loss on the sale or call of each debt security is determined by the specific identification method. At December 31, 2018 and 2017 , the Company had debt securities with carrying values of $1,333,455,000 and $1,447,808,000 , 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. Debt securities with an unrealized loss position are summarized as follows: December 31, 2018 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 $ 4,287 (27 ) 10,519 (135 ) 14,806 (162 ) U.S. government sponsored enterprises 43,400 (103 ) 35,544 (411 ) 78,944 (514 ) State and local governments 72,080 (922 ) 232,244 (10,400 ) 304,324 (11,322 ) Corporate bonds 119,111 (937 ) 114,800 (676 ) 233,911 (1,613 ) Residential mortgage-backed securities 132,405 (833 ) 537,202 (15,417 ) 669,607 (16,250 ) Commercial mortgage-backed securities 73,118 (402 ) 86,504 (1,954 ) 159,622 (2,356 ) Total available-for-sale $ 444,401 (3,224 ) 1,016,813 (28,993 ) 1,461,214 (32,217 ) Held-to-maturity State and local governments $ 87,392 (2,778 ) 126,226 (8,261 ) 213,618 (11,039 ) Total held-to-maturity $ 87,392 (2,778 ) 126,226 (8,261 ) 213,618 (11,039 ) Note 2. Debt Securities (continued) 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 ) Based on an analysis of its debt securities with unrealized losses as of December 31, 2018 and 2017 , 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 debt securities is expected to recover as payments are received and the securities approach maturity. At December 31, 2018 , management determined that it did not intend to sell debt securities with unrealized losses, and there was no expected requirement to sell any of its debt securities with unrealized losses before recovery of their amortized cost.

Loans Receivable, Net

Loans Receivable, Net	12 Months Ended
	Dec. 31, 2018
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 $ 887,742 720,728 Commercial loans Real estate 4,657,561 3,577,139 Other commercial 1,911,171 1,579,353 Total 6,568,732 5,156,492 Consumer and other loans Home equity 544,688 457,918 Other consumer 286,387 242,686 Total 831,075 700,604 Loans receivable 8,287,549 6,577,824 Allowance for loan and lease losses (131,239 ) (129,568 ) Loans receivable, net $ 8,156,310 6,448,256 Net deferred origination (fees) costs included in loans receivable $ (5,685 ) (2,643 ) Net purchase accounting (discounts) premiums included in loans receivable $ (25,172 ) (16,325 ) Weighted-average interest rate on loans (tax-equivalent) 4.97 % 4.81 % Note 3. Loans Receivable, Net (continued) At December 31, 2018 , the Company had $5,181,912,000 in variable rate loans and $3,105,637,000 in fixed rate loans. At December 31, 2018 , the Company had loans of $4,483,373,000 pledged as collateral for FHLB advances and FRB discount window. 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, 2018 and 2017 . No borrower had outstanding loans or commitments exceeding 10 percent of the Company’s consolidated stockholders’ equity as of December 31, 2018 . Loans that are serviced for others are not reported as assets. The principal balances of these loans were $181,281,000 and $4,042,000 at December 31, 2018 and 2017 , respectively, with the increase almost entirely due to loans serviced for others assumed with the FSB acquisition. The fair value of servicing rights was insignificant at December 31, 2018 and 2017 . There were no significant purchases or sales of portfolio loans during 2018 , 2017 and 2016 . 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, 2018 and 2017 was $59,528,000 and $82,350,000 , respectively. During 2018 , new loans to such related parties were $17,830,000 , repayments were $38,276,000 and the effect of changes in composition of related parties was $(2,376,000) . 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. Allowance for Loan and Lease Losses The ALLL is a valuation allowance for probable incurred credit losses. The following tables summarize the activity in the ALLL by loan class: Year ended December 31, 2018 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Balance at beginning of period $ 129,568 10,798 68,515 39,303 6,204 4,748 Provision for loan losses 9,953 474 4,343 1,916 (471 ) 3,691 Charge-offs (17,807 ) (728 ) (3,469 ) (5,045 ) (210 ) (8,355 ) Recoveries 9,525 87 3,059 1,986 288 4,105 Balance at end of period $ 131,239 10,631 72,448 38,160 5,811 4,189 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) The following tables disclose the recorded investment in loans and the balance in the ALLL by loan class: December 31, 2018 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Loans receivable Individually evaluated for impairment $ 108,788 12,685 68,837 20,975 3,497 2,794 Collectively evaluated for impairment 8,178,761 875,057 4,588,724 1,890,196 541,191 283,593 Total loans receivable $ 8,287,549 887,742 4,657,561 1,911,171 544,688 286,387 ALLL Individually evaluated for impairment $ 3,223 83 568 2,313 39 220 Collectively evaluated for impairment 128,016 10,548 71,880 35,847 5,772 3,969 Total ALLL $ 131,239 10,631 72,448 38,160 5,811 4,189 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 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. Aging Analysis The following tables present an aging analysis of the recorded investment in loans by loan class: December 31, 2018 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Accruing loans 30-59 days past due $ 24,312 5,251 9,477 4,282 3,213 2,089 Accruing loans 60-89 days past due 9,255 860 3,231 3,838 735 591 Accruing loans 90 days or more past due 2,018 788 — 492 428 310 Non-accrual loans 47,252 8,021 27,264 8,619 2,575 773 Total past due and non-accrual loans 82,837 14,920 39,972 17,231 6,951 3,763 Current loans receivable 8,204,712 872,822 4,617,589 1,893,940 537,737 282,624 Total loans receivable $ 8,287,549 887,742 4,657,561 1,911,171 544,688 286,387 Note 3. Loans Receivable, Net (continued) 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 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 $2,340,000 , $2,162,000 , and $2,364,000 for the years ended December 31, 2018 , 2017 , and 2016 , respectively. Impaired Loans 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. The following tables disclose information related to impaired loans by loan class: At or for the Year ended December 31, 2018 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Loans with a specific valuation allowance Recorded balance $ 19,197 1,957 9,345 7,268 120 507 Unpaid principal balance 19,491 2,220 9,345 7,268 120 538 Specific valuation allowance 3,223 83 568 2,313 39 220 Average balance 19,519 2,686 8,498 7,081 82 1,172 Loans without a specific valuation allowance Recorded balance 89,591 10,728 59,492 13,707 3,377 2,287 Unpaid principal balance 107,486 11,989 71,300 17,689 3,986 2,522 Average balance 106,747 10,269 73,889 17,376 3,465 1,748 Total Recorded balance 108,788 12,685 68,837 20,975 3,497 2,794 Unpaid principal balance 126,977 14,209 80,645 24,957 4,106 3,060 Specific valuation allowance 3,223 83 568 2,313 39 220 Average balance 126,266 12,955 82,387 24,457 3,547 2,920 Note 3. Loans Receivable, Net (continued) 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 Interest income recognized on impaired loans for the years ended December 31, 2018 , 2017 , and 2016 was not significant. Restructured Loans A restructured loan is considered a troubled debt restructuring 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 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, 2018 (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 25 4 8 10 2 1 Pre-modification recorded balance $ 21,995 724 12,901 7,813 252 305 Post-modification recorded balance $ 21,881 724 12,787 7,813 252 305 TDRs that subsequently defaulted Number of loans 1 1 — — — — Recorded balance $ 47 47 — — — — Note 3. Loans Receivable, Net (continued) 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 — — 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 — — The modifications for the TDRs that occurred during the years ended December 31, 2018 , 2017 and 2016 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 $6,793,000 , $5,987,000 and $5,331,000 for the years ended December 31, 2018 , 2017 and 2016 , 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, 2018 and 2017 and in residential real estate for the year ended December 31, 2016 . At December 31, 2018 and 2017 , the Company had $350,000 and $743,000 , respectively, of consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings are in process. At December 31, 2018 and 2017 , the Company had $698,000 and $893,000 , respectively, of OREO secured by residential real estate properties. There were $5,335,000 and $1,960,000 of additional unfunded commitments on TDRs outstanding at December 31, 2018 and 2017 , respectively. The amount of charge-offs on TDRs during 2018 , 2017 and 2016 was $1,685,000 , $2,984,000 and $557,000 , respectively.

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2018
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, 2018 December 31, 2017 Land $ 47,511 31,370 Buildings and construction in progress 231,854 182,592 Furniture, fixtures and equipment 90,030 83,177 Leasehold improvements 9,370 8,085 Accumulated depreciation (137,237 ) (127,876 ) Net premises and equipment $ 241,528 177,348 Depreciation expense for the years ended December 31, 2018 , 2017 , and 2016 was $16,019,000 , $14,758,000 , and $15,294,000 , respectively. Operating and Capital Leases 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, 2018 , 2017 , and 2016 was $4,224,000 , $3,629,000 , and $3,255,000 , respectively. The Company has included capital leases in premises and equipment and amortization 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, 2018 , 2017 , and 2016 was $12,000 , $164,000 , and $153,000 , 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, 2018 are as follows: (Dollars in thousands) Capital Leases Operating Leases Total Years ending December 31, 2019 $ 92 3,192 3,284 2020 92 2,682 2,774 2021 7 2,145 2,152 2022 — 1,427 1,427 2023 — 943 943 Thereafter — 5,352 5,352 Total minimum lease payments 191 15,741 15,932 Less: Amount representing interest 10 Present value of minimum lease payments 181 Less: Current portion of obligations under capital leases 84 Long-term portion of obligations under capital leases $ 97

Other Intangible Assets and Goo

Other Intangible Assets and Goodwill	12 Months Ended
	Dec. 31, 2018
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 $ 62,977 21,649 21,943 Accumulated amortization (13,735 ) (7,465 ) (9,596 ) Net carrying value $ 49,242 14,184 12,347 Aggregate amortization expense $ 6,270 2,494 2,970 Estimated amortization expense for the years ending December 31, 2019 $ 6,768 2020 6,598 2021 6,407 2022 6,187 2023 5,711 Core deposit intangibles increased $41,328,000 , $4,331,000 and $762,000 during 2018 , 2017 and 2016 , 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 $ 177,811 147,053 140,638 Acquisitions and adjustments 111,775 30,758 6,415 Net carrying value at end of period $ 289,586 177,811 147,053 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 2018 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 2018 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, 2018. 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, 2018 and 2017 .

Variable Interest Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2018
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 Bank is also the sole member of certain tax credit funds that make direct investments in qualified affordable housing projects (e.g., Low-Income Housing Tax Credit [“LIHTC”] partnerships). As such, the Company is the primary beneficiary of these tax credit funds and their assets, liabilities, and results of operations are included in the Company’s consolidated financial statements. 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 $ 80,123 57,796 Accrued interest receivable 96 94 Other assets 45,779 15,885 Total assets $ 125,998 73,775 Liabilities Other borrowed funds $ 14,527 7,964 Accrued interest payable 1 1 Other liabilities 125 98 Total liabilities $ 14,653 8,063 Note 6. Variable Interest Entities (continued) Unconsolidated Variable Interest Entities The Company has equity investments in LIHTC partnerships, both directly and through tax credit funds, with carrying values of $35,112,000 and $9,169,000 as of December 31, 2018 and 2017 , 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 $11,484,000 at December 31, 2018 , and the Company expects to fulfill the majority of these commitments during 2019. There were no impairment losses on the Company’s LIHTC investments during the years ended December 31, 2018 , 2017 , and 2016 . 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, 2018 December 31, 2017 December 31, Amortization expense $ 4,926 2,507 1,125 Tax credits and other tax benefits recognized 6,550 3,827 1,515 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, 2018
Deposits [Abstract]
Deposits	Deposits Time deposits that meet or exceed the Federal Deposit Insurance Corporation Insurance (“FDIC”) limit of $250,000 at December 31, 2018 and 2017 were $244,999,000 and $193,962,000 , respectively. The scheduled maturities of time deposits are as follows: (Dollars in thousands) Amount Years ending December 31, 2019 $ 634,197 2020 147,320 2021 71,500 2022 28,138 2023 20,310 Thereafter 19 $ 901,484 The Company reclassified $5,992,000 and $4,402,000 of overdraft demand deposits to loans as of December 31, 2018 and 2017 , 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, 2018 and 2017 was $26,260,000 and $25,641,000 , respectively.

Borrowings

Borrowings	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Borrowings	Borrowings The Company’s repurchase agreements totaled $396,151,000 and $362,573,000 at December 31, 2018 and 2017 , respectively, and are secured by debt securities with carrying values of $511,294,000 and $475,601,000 , 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, 2018 Remaining Contractual Maturity of the Agreements (Dollars in thousands) Overnight and Continuous Up to 30 Days Total Residential mortgage-backed securities $ 328,174 — 328,174 Commercial mortgage-backed securities 66,339 1,638 67,977 Total $ 394,513 1,638 396,151 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 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 debt 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, 2018 December 31, 2017 (Dollars in thousands) Amount Weighted Rate Amount Weighted Rate Maturing within one year $ 285,847 2.63 % $ 200,869 1.64 % Maturing one year through two years 1,572 3.50 % 887 2.05 % Maturing two years through three years 150,370 3.77 % 1,651 3.58 % Maturing three years through four years 918 5.25 % 148,721 2.69 % Maturing four years through five years 204 5.45 % 945 5.25 % Thereafter 1,264 4.82 % 922 5.42 % Total $ 440,175 3.03 % $ 353,995 2.11 % The Company’s other borrowings consisted of capital lease obligations and other debt obligations through consolidation of certain VIEs. At December 31, 2018 , 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, 2018
Debt Instruments [Abstract]
Subordinated Debentures	Subordinated Debentures The Company’s subordinated debentures are reflected in the table below. The amounts include fair value adjustments from acquisitions. December 31, 2018 Rate Structure Maturity Date (Dollars in thousands) Balance Rate Subordinated debentures owed to trust subsidiaries First Company Statutory Trust 2001 $ 3,332 5.827 % 3 month LIBOR plus 3.30% 07/31/2031 First Company Statutory Trust 2003 2,452 6.072 % 3 month LIBOR plus 3.25% 03/26/2033 Glacier Capital Trust II 46,393 5.186 % 3 month LIBOR plus 2.75% 04/07/2034 Citizens (ID) Statutory Trust I 5,155 5.438 % 3 month LIBOR plus 2.65% 06/17/2034 Glacier Capital Trust III 36,083 3.726 % 3 month LIBOR plus 1.29% 04/07/2036 Glacier Capital Trust IV 30,928 4.358 % 3 month LIBOR plus 1.57% 09/15/2036 Bank of the San Juans Bancorporation Trust I 1,935 4.558 % 3 month LIBOR plus 1.82% 03/01/2037 Total subordinated debentures owed to trust subsidiaries 126,278 Tier 2 subordinated debentures 7,773 6.625 % Fixed 10/01/2025 Total subordinated debentures $ 134,051 Subordinated Debentures Owed to Trust Subsidiaries 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. Note 9. Subordinated Debentures (continued) 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 the $15 billion threshold as a result of organic growth. Once the Company has crossed the $15 billion threshold, any subsequent merger or acquisition would result in disqualification of the Company’s combined trust preferred securities as Tier 1 capital ; however, the trust preferred securities would be included in Tier 2 capital. If the Company crosses the $15 billion threshold as a direct result of an acquisition, neither the Company’s nor the acquired institution’s trust preferred securities would continue to qualify as Tier 1 capital, but instead would be included in Tier 2 capital. All of the Company’s trust preferred securities qualified as Tier 1 capital instruments at December 31, 2018 . Tier 2 Subordinated Debentures The Company acquired subordinated debentures with the FSB acquisition that qualify as Tier 2 capital under the applicable capital adequacy rules and regulations promulgated by the FRB. The Tier 2 subordinated debentures are not deposits and are not insured by the FDIC or any other government agency. Such obligations are subordinated to the claims of general creditors, are unsecured and are ineligible as collateral. The principal amount is due at maturity and interest distributions are payable quarterly. The Tier 2 subordinated debentures shall not be prepaid prior to the fifth anniversary of the closing date, which is September 30, 2020, except in the event the obligation no longer qualifies as Tier 2 capital (“Tier 2 capital event”) or the interest payable is no longer deductible (“tax event”). Any prepayment made in connection with a Tier 2 capital event or a tax event will be subject to obtaining the prior approval of the FRB. Prepayment on or after the fifth anniversary of the closing date is allowed at any time with notice. For additional information on regulatory capital, see Note 11.

Derivatives and Hedging Activit

Derivatives and Hedging Activities	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedging Activities	Derivatives and Hedging Activities Interest Rate Swap Derivatives 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. Note 10. Derivatives and Hedging Activities (continued) The Company’s interest rate swap derivative financial instruments as of December 31, 2018 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. 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 periods. 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 , $8,013,000 and $8,035,000 during 2018 , 2017 and 2016 , 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 $1,663,000 of the unrealized loss reported in OCI at December 31, 2018 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 $ 3,286 444 (1,643 ) Amount of loss reclassified from OCI to interest expense (2,334 ) (4,892 ) (6,417 ) The following table discloses the offsetting of financial assets and interest rate swap derivative assets. December 31, 2018 December 31, 2017 (Dollars in thousands) Gross Amount of Recognized Assets Gross Amount Offset in the Statements of Financial Position Net Amounts of Assets Presented in the Statements of Financial Position Gross Amount of Recognized Assets Gross Amount Offset in the Statements of Financial Position Net Amounts of Assets Presented in the Statements of Financial Position Interest rate swaps $ 139 (139 ) — — — — Note 10. Derivatives and Hedging Activities (continued) The following table discloses the offsetting of financial liabilities and interest rate swap derivative liabilities. December 31, 2018 December 31, 2017 (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 $ 3,908 (139 ) 3,769 9,389 — 9,389 Pursuant to the interest rate swap agreements, the Company pledged collateral to the counterparty in the form of debt securities totaling $4,730,000 at December 31, 2018 . There was $0 collateral pledged from the counterparty to the Company as of December 31, 2018 . 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. Residential Real Estate Derivatives At December 31, 2018 , the Company had residential real estate derivatives for commitments (“interest rate locks”) to fund certain residential real estate loans to be sold into the secondary market. At December 31, 2018 and 2017 , loans with interest rate lock commitments totaled $59,974,000 and $67,861,000 , respectively, and the fair value of the related derivatives was included in other assets with corresponding changes recorded in gain on sale of loans. It has been the Company’s practice to enter into “best efforts” forward sales commitments for the future delivery of residential real estate loans to third party investors 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. Forward sales commitments on a “best efforts” basis are not designated in hedge relationships until the loan is funded. Due to the forward sales commitments being short-term in nature, the corresponding derivatives are not significant. During 2018, the Company also began to enter into free-standing derivatives to mitigate the interest rate risk associated with certain residential real estate loans to be sold. These derivatives include forward commitments to sell to-be-announced securities (“TBA”) which are used to economically hedge the interest rate risk associated with certain residential real estate loans held for sale and unfunded commitments. At December 31, 2018 , TBA commitments were $40,750,000 and the fair value of the related derivatives was included in other liabilities with corresponding changes recorded in gain on sale of loans.

Regulatory Capital

Regulatory Capital	12 Months Ended
	Dec. 31, 2018
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 2018 is 1.875 percent . The Company has elected to opt-out of the requirement to include most components of accumulated other comprehensive income. As of December 31, 2018 , 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, 2018 and 2017 , 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, 2018 that management believes have changed the Company’s or Bank’s risk-based capital category. Note 11. Regulatory Capital 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, 2018 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 $ 1,437,889 14.70 % $ 782,453 8.00 % N/A N/A Glacier Bank 1,401,991 14.35 % 781,430 8.00 % $ 976,787 10.00 % Tier 1 capital (to risk-weighted assets) Consolidated 1,308,017 13.37 % 586,840 6.00 % N/A N/A Glacier Bank 1,279,778 13.10 % 586,072 6.00 % 781,430 8.00 % Common Equity Tier 1 (to risk-weighted assets) Consolidated 1,183,517 12.10 % 440,130 4.50 % N/A N/A Glacier Bank 1,279,778 13.10 % 439,554 4.50 % 634,911 6.50 % Tier 1 capital (to average assets) Consolidated 1,308,017 11.35 % 461,130 4.00 % N/A N/A Glacier Bank 1,279,778 11.08 % 462,072 4.00 % 577,590 5.00 % December 31, 2017 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 $ 1,232,089 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 % ______________________________ N/A - Not applicable

Stock-based Compensation Plan

Stock-based Compensation Plan	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based Compensation Plan	Stock-based Compensation Plan The Company’s stock-based compensation plan, 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, 2018 , the number of shares available to award to employees and directors under the 2015 Stock Incentive Plan was 2,139,518 . During 2018, the Company also assumed a stock-based compensation plan through the Collegiate acquisition. This plan has an insignificant amount of stock options outstanding at December 31, 2018 and no additional shares may be awarded from the plan. Restricted Stock Awards The Company has awarded restricted stock to select employees and directors under the 2015 Stock Incentive Plan. 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. 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, 2018 , 2017 and 2016 was $3,703,000 , $3,764,000 and $2,870,000 , respectively, and the recognized income tax benefit related to this expense was $934,000 , $1,452,000 and $1,112,000 . As of December 31, 2018 , total unrecognized compensation expense of $4,013,000 related to restricted stock awards is expected to be recognized over a weighted-average period of 2.0 years . The fair value of restricted stock awards that vested during the years ended December 31, 2018 , 2017 and 2016 was $3,319,000 , $3,746,000 and $2,624,000 , respectively, and the income tax benefit related to these awards was $1,126,000 , $1,998,000 and $1,053,000 , respectively. Upon vesting of restricted stock awards, the shares are issued from the Company’s authorized stock balance. The following table summarizes the restricted stock award activity for the year ended December 31, 2018 : Restricted Stock Weighted- Average Grant Date Fair Value Non-vested at December 31, 2017 183,178 $ 29.84 Granted 114,366 39.92 Vested (111,273 ) 29.82 Forfeited (4,288 ) 37.64 Non-vested at December 31, 2018 181,983 36.03 The average remaining contractual term on non-vested restricted stock awards at December 31, 2018 is 0.9 years . The aggregate intrinsic value of the non-vested restricted stock awards at December 31, 2018 was $7,210,000 .

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2018
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 non-insured 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, 2018 , 2017 , and 2016 was $15,406,000 , $10,100,000 and $9,041,000 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, 2018 , 2017 and 2016 was $4,037,000 , $3,224,000 , and $2,946,000 , 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 $803,000 , $739,000 , and $967,000 , for the years ending December 31, 2018 , 2017 , and 2016 , 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, 2018 , 2017 , and 2016 for the plans was $502,000 , $481,000 and $431,000 , respectively. In connection with several acquisitions, the Company assumed the obligations of deferred compensation plans for certain key employees. As of December 31, 2018 and 2017 , the liability related to the obligations was $13,651,000 and $11,275,000 , respectively, and was included in other liabilities. The total earnings for the years ended December 31, 2018 , 2017 , and 2016 for the acquired plans was $801,000 , $588,000 and $632,000 , respectively. 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, 2018 , 2017 and 2016 was $423,000 , $287,000 , and $299,000 , 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, 2018 , 2017 , and 2016 for this plan was $122,000 , $105,000 , and $85,000 , respectively.

Other Expenses

Other Expenses	12 Months Ended
	Dec. 31, 2018
Other Expenses [Abstract]
Other Expenses	Other Expenses Other expenses consists of the following: Years ended (Dollars in thousands) December 31, December 31, December 31, Consulting and outside services $ 7,219 5,331 5,683 Mergers and acquisition expenses 6,618 2,130 1,732 Debit card expenses 5,104 7,189 8,462 Telephone 4,487 3,891 3,828 Employee expenses 4,412 4,160 3,573 Business development 4,172 3,333 3,286 VIE amortization and other expenses 3,618 3,109 2,702 Loan expenses 3,462 3,080 3,611 Printing and supplies 3,264 2,661 2,800 Postage 3,104 2,684 2,785 Legal fees 1,763 1,106 1,027 Accounting and audit fees 1,456 1,848 1,613 Checking and operating expenses 1,234 1,760 2,942 ATM expenses 1,217 1,720 880 Other 3,164 3,043 2,646 Total other expenses $ 54,294 47,045 47,570

Federal and State Income Taxes

Federal and State Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Federal and State Income Taxes	Federal and State Income Taxes The Tax Cuts and Jobs Act (“Tax Act”) was enacted on December 22, 2017 and resulted in a decrease in the federal marginal corporate income 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 the deferred tax assets and deferred tax liabilities (“net deferred tax asset”). 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 $ 21,510 29,555 30,461 State 11,960 9,183 9,283 Total current income tax expense 33,470 38,738 39,744 Deferred 1 Federal 5,372 22,246 (70 ) State 1,489 3,641 (12 ) Total deferred income tax expense (benefit) 6,861 25,887 (82 ) Total income tax expense $ 40,331 64,625 39,662 ______________________________ 1 Includes tax benefit of operating loss carryforwards of $443,000 , $644,000 and $571,000 for the years ended December 31, 2018 , 2017 , and 2016 , respectively. Note 15. Federal and State Income Taxes (continued) Combined federal and state income tax expense differs from that computed at the federal statutory corporate income tax rate as follows: Years ended December 31, December 31, December 31, Federal statutory rate 21.0 % 35.0 % 35.0 % State taxes, net of federal income tax benefit 4.8 % 4.6 % 3.8 % Tax rate change — % 10.9 % — % Tax-exempt interest income (5.0 )% (10.5 )% (12.2 )% Tax credits (4.2 )% (3.2 )% (2.1 )% Other, net 1.6 % (1.1 )% 0.2 % Effective income tax rate 18.2 % 35.7 % 24.7 % 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 $ 33,313 32,890 Acquisition fair market value adjustments 6,380 4,139 Deferred compensation 6,251 5,640 Employee benefits 2,939 2,615 Net operating loss carryforwards 2,525 2,841 Available-for-sale debt securities 2,244 — Interest rate swap agreements 955 2,379 Other real estate owned 801 5,126 Other 4,798 3,673 Total gross deferred tax assets 60,206 59,303 Deferred tax liabilities Intangibles (12,667 ) (4,161 ) Depreciation of premises and equipment (10,776 ) (2,863 ) Deferred loan costs (6,436 ) (5,854 ) FHLB stock dividends (2,722 ) (2,602 ) Debt modification costs (1,173 ) (1,591 ) Available-for-sale debt securities — (1,707 ) Other (2,868 ) (2,181 ) Total gross deferred tax liabilities (36,642 ) (20,959 ) Net deferred tax asset $ 23,564 38,344 The Company has federal net operating loss carryforwards of $9,337,000 expiring between 2030 and 2035 . The Company has Colorado net operating loss carryforwards of $12,988,000 expiring between 2031 and 2032 . The net operating loss carryforwards originated from acquisitions. Note 15. Federal and State Income Taxes (continued) 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, 2018 : Years ended December 31, Federal 2015, 2016 and 2017 Montana 2015, 2016 and 2017 Idaho 2015, 2016 and 2017 Utah 2015, 2016 and 2017 Colorado 2014, 2015, 2016 and 2017 Arizona 2017 The Company had no unrecognized income tax benefits as of December 31, 2018 and 2017 . 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, 2018 , 2017 , and 2016 was not significant. The Company had no accrued liabilities for the payment of interest or penalties at December 31, 2018 and 2017 . The Company has assessed the need for a valuation allowance and determined that a valuation allowance was not necessary at December 31, 2018 and 2017 . 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 expected future net operating losses (for tax purposes).

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss The following table illustrates the activity within accumulated other comprehensive loss by component, net of tax: (Dollars in thousands) Gains (Losses) on Available-For-Sale Debt Securities Losses on Derivatives Used for Cash Flow Hedges Total Balance at January 1, 2016 $ 13,935 (11,946 ) 1,989 Other comprehensive loss before reclassifications (13,113 ) (1,006 ) (14,119 ) Reclassification adjustments for losses 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 losses included in net income 391 3,005 3,396 Reclassifications 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 ) Other comprehensive (loss) income before reclassifications (11,653 ) 2,453 (9,200 ) Reclassification adjustments for losses included in net income 9 1,743 1,752 Net current period other comprehensive (loss) income (11,644 ) 4,196 (7,448 ) Balance at December 31, 2018 $ (6,613 ) (2,814 ) (9,427 ) ______________________________ 1 Reclassifications were due to the one-time revaluation of the net deferred tax asset as a result of the Tax Act. For additional information on the Tax Act, see Note 15.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2018
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 and stock options were exercised, 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 $ 181,878 116,377 121,131 Average outstanding shares - basic 83,603,515 77,537,664 76,278,463 Add: dilutive restricted stock awards and stock options 73,670 69,941 63,373 Average outstanding shares - diluted 83,677,185 77,607,605 76,341,836 Basic earnings per share $ 2.18 1.50 1.59 Diluted earnings per share $ 2.17 1.50 1.59 There were 1,357, 0 and 0 restricted stock awards and stock options excluded from the diluted average outstanding share calculation for the years ended December 31, 2018 , 2017 , and 2016 , respectively. Anti-dilution occurs when the unrecognized compensation cost per share of a restricted stock award or the exercise price of a stock option exceeds the market price of the Company’s stock.

Parent Holding Company Informat

Parent Holding Company Information (Condensed)	12 Months Ended
	Dec. 31, 2018
Condensed Financial Information 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 $ 22,000 9,304 Interest bearing cash deposits 42,299 38,420 Cash and cash equivalents 64,299 47,724 Other assets 12,639 8,871 Investment in subsidiaries 1,612,115 1,281,392 Total assets $ 1,689,053 1,337,987 Liabilities and Stockholders’ Equity Dividends payable $ 25,726 265 Subordinated debentures 134,051 126,135 Other liabilities 13,422 12,530 Total liabilities 173,199 138,930 Common stock 845 780 Paid-in capital 1,051,253 797,997 Retained earnings 473,183 402,259 Accumulated other comprehensive loss (9,427 ) (1,979 ) Total stockholders’ equity 1,515,854 1,199,057 Total liabilities and stockholders’ equity $ 1,689,053 1,337,987 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 $ 153,574 119,000 108,350 Gain on sale of investments — 3 — Intercompany charges for services 16,523 14,299 12,248 Other income 1,284 225 311 Total income 171,381 133,527 120,909 Expenses Compensation and employee benefits 20,873 17,864 15,665 Other operating expenses 12,201 10,425 7,701 Total expenses 33,074 28,289 23,366 Income before income tax benefit and equity in undistributed net income of subsidiaries 138,307 105,238 97,543 Income tax benefit 3,773 2,983 4,040 Income before equity in undistributed net income of subsidiaries 142,080 108,221 101,583 Equity in undistributed net income of subsidiaries 39,798 8,156 19,548 Net Income $ 181,878 116,377 121,131 Comprehensive Income $ 174,430 122,131 111,760 Condensed Statements of Cash Flows Years ended (Dollars in thousands) December 31, December 31, December 31, Operating Activities Net income $ 181,878 116,377 121,131 Adjustments to reconcile net income to net cash provided by operating activities: Subsidiary income in excess of dividends distributed (39,798 ) (8,156 ) (19,548 ) Amortization of purchase accounting adjustments 13 143 143 Gain on sale of investments — (3 ) — Stock-based compensation, net of tax benefits 1,219 1,460 804 Net change in other assets and other liabilities (3,222 ) 5,051 (297 ) Net cash provided by operating activities 140,090 114,872 102,233 Investing Activities Sales of available-for-sale securities — 27 — Net (increase) decrease of premises and equipment (300 ) (79 ) 771 Proceeds from sale of non-marketable equity securities — 114 55 Equity contributions to subsidiaries (24,989 ) (17,565 ) (3,475 ) Net cash used in investing activities (25,289 ) (17,503 ) (2,649 ) Financing Activities Net increase in other borrowed funds (11,543 ) — — Cash dividends paid (85,493 ) (111,720 ) (84,040 ) Tax withholding payments for stock-based compensation (1,190 ) (1,531 ) (600 ) Net cash used in financing activities (98,226 ) (113,251 ) (84,640 ) Net increase (decrease) in cash, cash equivalents and restricted cash 16,575 (15,882 ) 14,944 Cash, cash equivalents and restricted cash at beginning of year 47,724 63,606 48,662 Cash, cash equivalents and restricted cash at end of year $ 64,299 47,724 63,606

Unaudited Quarterly Financial D

Unaudited Quarterly Financial Data (Condensed)	12 Months Ended
	Dec. 31, 2018
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 2018 (Dollars in thousands, except per share data) March 31 June 30 September 30 December 31 Interest income $ 103,066 117,715 122,905 125,310 Interest expense 7,774 9,161 9,160 9,436 Net interest income 95,292 108,554 113,745 115,874 Provision for loan losses 795 4,718 3,194 1,246 Net interest income after provision for loan losses 94,497 103,836 110,551 114,628 Non-interest income 26,086 31,828 32,416 28,494 Non-interest expense 73,627 81,795 82,829 81,876 Income before income taxes 46,956 53,869 60,138 61,246 Federal and state income tax expense 8,397 9,485 10,802 11,647 Net income $ 38,559 44,384 49,336 49,599 Basic earnings per share $ 0.48 0.53 0.58 0.59 Diluted earnings per share $ 0.48 0.52 0.58 0.59 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

Fair Value of Assets and Liabil

Fair Value of Assets and Liabilities	12 Months Ended
	Dec. 31, 2018
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, 2018 , 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, 2018 . Debt securities, available-for-sale: fair value for available-for-sale debt 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 debt 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 debt 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, at fair value: 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 losses of $155,000 , net gains of $994,000 and $0 for the years ended December 31, 2018 , 2017 and 2016 , respectively, from the changes in fair value of 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, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Debt securities, available-for-sale U.S. government and federal agency $ 23,649 — 23,649 — U.S. government sponsored enterprises 120,208 — 120,208 — State and local governments 852,250 — 852,250 — Corporate bonds 290,817 — 290,817 — Residential mortgage-backed securities 792,915 — 792,915 — Commercial mortgage-backed securities 491,824 — 491,824 — Loans held for sale, at fair value 33,156 — 33,156 — Total assets measured at fair value on a recurring basis $ 2,604,819 — 2,604,819 — Interest rate swaps $ 3,769 — 3,769 — Total liabilities measured at fair value on a recurring basis $ 3,769 — 3,769 — 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, 2017 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Debt 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, at fair value 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 — 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, 2018 . Other real estate owned: OREO is initially recorded at fair value less estimated cost to sell, establishing a new cost basis. OREO is subsequently accounted for at lower of cost or 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, 2018 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 $ 1,011 — — 1,011 Collateral-dependent impaired loans, net of ALLL 6,985 — — 6,985 Total assets measured at fair value on a non-recurring basis $ 7,996 — — 7,996 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 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 $ 1,011 Sales comparison approach Selling costs 8.0% - 15.0% (9.2%) Collateral-dependent impaired loans, net of ALLL $ 2,384 Sales comparison approach Selling costs 8.0% - 20.0% (9.9%) 4,601 Combined approach Selling costs 10.0% - 10.0% (10.0%) $ 6,985 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 $ 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 ______________________________ 1 The range for selling cost inputs represents reductions to the fair value of the assets. Fair Value 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 not carried at fair value. Receivables and payables due in one year or less, equity securities without readily determinable fair values and deposits with no defined or contractual maturities are excluded. Fair Value Measurements At the End of the Reporting Period Using (Dollars in thousands) Carrying Amount December 31, 2018 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 $ 203,790 203,790 — — Debt securities, held-to-maturity 297,915 — 288,256 — Loans receivable, net of ALLL 8,156,310 — — 8,079,112 Total financial assets $ 8,658,015 203,790 288,256 8,079,112 Financial liabilities Term deposits $ 1,070,208 — 1,069,777 — FHLB advances 440,175 — 439,615 — Repurchase agreements and other borrowed funds 410,859 — 410,859 — Subordinated debentures 134,051 — 120,302 — Total financial liabilities $ 2,055,293 — 2,040,553 — 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, 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 — — Debt securities, held-to-maturity 648,313 — 660,086 — Loans receivable, net of ALLL 6,448,256 — 6,219,515 114,771 Total financial assets $ 7,296,573 200,004 6,879,601 114,771 Financial liabilities Term deposits $ 977,302 — 978,803 — FHLB advances 353,995 — 352,886 — Repurchase agreements and other borrowed funds 370,797 — 370,797 — Subordinated debentures 126,135 — 98,023 — Total financial liabilities $ 1,828,229 — 1,800,509 —

Contingencies and Commitments

Contingencies and Commitments	12 Months Ended
	Dec. 31, 2018
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 $ 1,948,516 1,565,112 Letters of credit 45,263 40,082 Total outstanding commitments $ 1,993,779 1,605,194 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, 2018
Business Combinations [Abstract]
Mergers and Acquisitions	Mergers and Acquisitions The Company has completed the following acquisitions during the last two years: • Inter-Mountain Bancorp., Inc. and its wholly-owned subsidiary, First Security Bank • Columbine Capital Corp., and its wholly-owned subsidiary, Collegiate Peaks Bank • TFB Bancorp, Inc. and its subsidiary, The Foothills Bank The assets and liabilities of FSB, Collegiate and Foothills were recorded on the Company’s consolidated statements of financial condition at their estimated fair values as of their acquisition dates 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 FSB, Collegiate and Foothills acquisitions: (Dollars in thousands) FSB February 28, 2018 Collegiate January 31, 2018 Foothills April 30, 2017 Fair value of consideration transferred Fair value of Company shares issued, net of equity issuance costs $ 181,043 69,764 46,673 Cash consideration for outstanding shares — 16,265 17,342 Effective settlement of a pre-existing relationship — 10,054 — Total fair value of consideration transferred 181,043 96,083 64,015 Recognized amounts of identifiable assets acquired and liabilities assumed Identifiable assets acquired Cash and cash equivalents 24,397 93,136 13,251 Debt securities 271,865 42,177 25,420 Loans receivable 627,767 354,252 292,529 Core deposit intangible 1 31,053 10,275 4,331 Accrued income and other assets 78,274 15,911 19,699 Total identifiable assets acquired 1,033,356 515,751 355,230 Liabilities assumed Deposits 877,586 437,171 296,760 Borrowings 2 36,880 12,509 22,800 Accrued expenses and other liabilities 14,175 5,435 2,264 Total liabilities assumed 928,641 455,115 321,824 Total identifiable net assets 104,715 60,636 33,406 Goodwill recognized $ 76,328 35,447 30,609 ______________________________ 1 The core deposit intangible for each acquisition was determined to have an estimated life of 10 years . 2 Borrowings assumed with the FSB acquisition include Tier 2 subordinated debentures of $7,903,000 . 2018 Acquisitions On February 28, 2018 , the Company acquired 100 percent of the outstanding common stock of Inter-Mountain Bancorp., Inc. and its wholly-owned subsidiary, First Security Bank, a community bank based in Bozeman, Montana. FSB provides banking services to individuals and businesses throughout Montana with locations in Bozeman, Belgrade, Big Sky, Choteau, Fairfield, Fort Benton, Three Forks, Vaughn and West Yellowstone. The acquisition expands the Company’s presence in the Bozeman and Golden Triangle markets in Montana and further diversifies the Company’s loan, customer and deposit base. FSB merged into the Bank and became a new bank division headquartered in Bozeman and the Bank’s existing Bozeman-based division, Big Sky Western Bank, combined with the new FSB division. The agriculture-focused northern branches of FSB combined with the Bank’s First Bank of Montana division. The FSB acquisition was valued at $181,043,000 and resulted in the Company issuing 4,654,091 shares of its common stock. 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 February 28, 2018 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 FSB. None of the goodwill is deductible for income tax purposes as the acquisition was accounted for as a tax-free exchange. Note 22. Mergers and Acquisitions (continued) 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 locations in Aurora, Buena Vista, Denver and Salida. The acquisition expands the Company’s presence in Colorado to the mountains and along the Front Range and further diversifies the Company’s loan, customer and deposit base. Collegiate merged into the Bank and operates as a separate Bank division under its existing name and management team. The Collegiate acquisition was valued at $96,083,000 and resulted in the Company issuing 1,778,777 shares of its common stock and paying $16,265,000 in cash in exchange for all of Collegiate’s outstanding common stock shares and $10,054,000 due to an effective settlement of pre-existing receivable from Columbine Capital Corp. 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 January 31, 2018 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 Collegiate. None of the goodwill is deductible for income tax purposes as the acquisition was accounted for as a tax-free exchange. The fair values of the FSB and Collegiate assets acquired include loans with fair values of $627,767,000 and $354,252,000 , respectively. The gross principal and contractual interest due under the FSB and Collegiate contracts was $632,370,000 and $355,364,000 , 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 $4,714,000 and $1,683,000 of expenses in connection with the FSB and Collegiate acquisitions, respectively, during the year ended December 31, 2018 . Mergers and acquisition expenses are included in other expense in the Company's consolidated statements of operations and consist of third-party costs, conversion costs and employee retention and severance expenses. Total income consisting of net interest income and non-interest income of the acquired operations of FSB was approximately $42,796,000 and net income was approximately $11,303,000 from February 28, 2018 to December 31, 2018 . Total income consisting of net interest income and non-interest income of the acquired operations of Collegiate was approximately $23,921,000 and net income was approximately $4,962,000 from January 31, 2018 to December 31, 2018 . The following unaudited pro forma summary presents consolidated information of the Company as if the FSB and Collegiate acquisitions had occurred on January 1, 2017: Years ended (Dollars in thousands) December 31, December 31, Net interest income and non-interest income $ 560,979 520,634 Net income 177,267 138,042 2017 Acquisition 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 locations 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. The fair value of the Foothills assets acquired include loans with fair values of $292,529,000 . The gross principal and contractual interest due under the Foothills contracts was $303,527,000 . The Company evaluated the principal and contractual interest due at the acquisition date and determined that an insignificant amount was not expected to be collectible. Note 22. Mergers and Acquisitions (continued) The Company incurred $1,127,000 of expenses in connection with the Foothills acquisition during the year ended December 31, 2017 . Mergers and acquisition expenses are included in other expense in the Company's consolidated statements of operations and consist of third-party costs, conversion costs and employee retention and severance expenses. 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

Subsequent Event

Subsequent Event	12 Months Ended
	Dec. 31, 2018
Subsequent Events [Abstract]
Subsequent Event	Subsequent Event On January 16, 2019, the Company announced the signing of a definitive agreement to acquire FNB Bancorp and its wholly-owned subsidiary, The First National Bank of Layton, a community bank based in Layton, Utah (collectively, “FNB”). FNB provides banking services to individuals and businesses throughout Utah with locations in Layton, Bountiful, Clearfield, and Draper. As of December 31, 2018, FNB had total assets of $334,709,000 , gross loans of $246,724,000 and total deposits of $285,752,000 . The acquisition is subject to required regulatory approvals and other customary conditions of closing and is anticipated to take place in the second quarter of 2019. Upon closing of the transaction, the branches of FNB, along with the Bank’s existing branches operating in Utah, will operate as a new division of the Bank.

Nature of Operations and Summ_2

Nature of Operations and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
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 debt 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 other assets on the Company's statements of financial condition. In February 2018, the Company completed its acquisition of Inter-Mountain Bancorp., Inc. and its wholly-owned subsidiary, First Security Bank, a community bank based in Bozeman, Montana (collectively, “FSB”). In January 2018, the Company completed its acquisition of Columbine Capital Corp., and its wholly-owned subsidiary, Collegiate Peaks Bank, a community bank based in Buena Vista, Colorado (collectively, “Collegiate”). 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, a community bank based in Missoula, Montana. The business combinations were accounted for using the acquisition method, with the results of operations 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.
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, 2018 was $53,626,000 .
Debt Securities	Debt 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 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 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 debt 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 debt 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 debt 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 debt 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 debt 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 debt securities, see Note 2.
Temporary versus Other-Than-Temporary Impairment	Temporary versus Other-Than-Temporary Impairment The Company assesses individual debt securities in its investment portfolio for impairment at least on a quarterly basis, and more frequently when economic or market conditions warrant. A debt security 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 debt 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 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 other real estate owned (“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 to 40 years and the estimated useful life for furniture, fixtures, and equipment is 3 to 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 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, 2018 and 2017 , 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 2018 and 2017 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.
Equity Securities	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 fair value, FHLB stock is carried at cost and evaluated for impairment. 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. Note 1. Nature of Operations and Summary of Significant Accounting Policies (continued) The Company also has an insignificant amount of marketable equity securities that are included in other assets on the Company’s statements of financial condition. Marketable equity securities with readily determinable fair values are measured at fair value and changes in fair value are recognized in other income. Marketable equity securities without readily determinable fair values are carried at cost, minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment.
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. 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. For highly effective hedges, the ineffective portion of the gain or loss on derivative instruments, if any, would be amortized over the remaining life the hedging instrument using a systematic and rational method. For the years ended December 31, 2018 , 2017 , and 2016 , 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.
Revenue Recognition	Revenue Recognition The Company recognizes revenue when services or products are transferred to customers in an amount that reflects the consideration to which the Company expects to be entitled. The Company’s principal source of revenue is interest income from debt securities and loans. Revenue from contracts with customers within the scope of Accounting Standards Codification ™ (“ASC”) Topic 606 was $76,664,000 , $69,808,000 , and $64,722,000 for the years ended December 31, 2018 , 2017 , and 2016 , respectively, and largely consisted of revenue from service charges and other fees from deposits (e.g., overdraft fees, ATM fees, debit card fees). Due to the short-term nature of the Company’s contracts with customers, an insignificant amount of receivables related to such revenue was recorded at December 31, 2018 and 2017 and there were no impairment losses recognized. Policies specific to revenue from contracts with customers include the following: Service Charges. Revenue from service charges consists of service charges and fees on deposit accounts under depository agreements with customers to provide access to deposited funds and, when applicable, pay interest on deposits. Service charges on deposit accounts may be transactional or non-transactional in nature. Transactional service charges occur in the form of a service or penalty and are charged upon the occurrence of an event (e.g., overdraft fees, ATM fees, wire transfer fees). Transactional service charges are recognized as services are delivered to and consumed by the customer, or as penalty fees are charged. Non-transactional service charges are charges that are based on a broader service, such as account maintenance fees and dormancy fees, and are recognized on a monthly basis. Note 1. Nature of Operations and Summary of Significant Accounting Policies (continued) Debit Card Fees. Revenue from debit card fees includes interchange fee income from debit cards processed through card association networks. Interchange fees represent a portion of a transaction amount that the Company and other involved parties retain to compensate themselves for giving the cardholder immediate access to funds. Interchange rates are generally set by the card association networks and are based on purchase volumes and other factors. The Company records interchange fees as services are provided.
Stock-based Compensation	Stock-based Compensation Stock-based compensation awards granted, comprised of restricted stock awards and stock options, 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. 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 2017 and 2016 financial statements to conform to the 2018 presentation.
Accounting Guidance Adopted in 2018 and Pending Adoption at December 31, 2018	Accounting Guidance Adopted in 2018 The 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 Updates (“ASU”) that may have had a material effect on the Company’s financial position or results of operations. ASU 2017-12 - 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 were effective for public business entities for the first interim and annual reporting periods beginning after December 15, 2018 and early adoption was permitted. The Company early adopted the amendments effective November 30, 2018 and determined the impact of these amendments did not have a significant impact on the Company’s financial position or results of operations. As a result of the adoption of the amendments, the Company redesignated state and local government securities with a carrying value of $270,331,000 from held-to-maturity classification to available-for-sale classification; such securities are eligible to be hedged under the last-of-layer method under the amendments and, therefore, qualified for such reclassification. The Company’s accounting procedures were modified upon adoption of the amendments to include the assessment of on-going hedge effectiveness utilizing qualitative measurement tests. For additional information on derivatives, see Note 10. ASU 2016-01 - Financial Instruments - Overall. In January 2016, FASB amended ASC Topic 825 to address certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. The amendments were effective for public business entities for the first interim and annual reporting periods beginning after December 15, 2017. Amendments were to be applied 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 impacted the Company as follows: 1) equity investments (with certain exclusions) are to be measured at fair value with the changes recognized in net income; 2) an exit price must be utilized when measuring the fair value of financial instruments; and 3) additional disclosures are required relating to OCI, the evaluation of a valuation allowance on a deferred tax asset related to available-for-sale debt securities in combination with the entity’s other deferred tax assets, and other disclosures. The Company adopted the amendments effective January 1, 2018 and determined that the impact of these amendments did not have a significant impact on the Company’s equity securities, fair value disclosures, financial position or results of operations. The amendments changed the method utilized to disclose the fair value of the loan portfolio to an exit price notion when measuring fair value. The Company developed processes to comply with the disclosure requirements of such amendments and accounting policies and procedures were updated accordingly. For additional information on fair value of assets and liabilities, see Note 20. ASU 2014-09 - Revenue from Contracts With Customers. 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 established 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 were provided for a company or organization to follow to achieve such core principle. The new guidance also included a cohesive set of disclosure requirements that provided 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 Company adopted the new revenue recognition guidance effective January 1, 2018 and determined the majority of the Company’s revenue sources, such as interest income from debt securities and loans, fee income from loans and gain on sale of loans, were not within the scope of Topic 606. The Company 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 and determined the adoption of the guidance did not have a significant impact to the Company’s financial position or results of operations; however, OREO policies and procedures were updated and implemented and new disclosures about the Company’s revenue have been incorporated into the notes to the financial statements. Note 1. Nature of Operations and Summary of Significant Accounting Policies (continued) Accounting Guidance Pending Adoption at December 31, 2018 The following paragraphs provide descriptions of newly issued but not yet effective ASUs that could have a material effect on the Company’s financial position or results of operations. ASU 2017-08 - 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 will 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. When the Company adopts these amendments on January 1, 2019, the Company will adjust $24,102,000 of the premium associated with debt securities to retained earnings. The Company has finalized its review of the amendments and has updated its accounting policies and procedures. ASU 2017-04 - Intangibles - Goodwill and Other. 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 2018, the Company performed its impairment assessment and determined the fair value of the aggregated reporting units exceeded 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. ASU 2016-13 - Financial Instruments - Credit Losses. 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 debt securities. In addition, the current accounting policy and procedures for other-than-temporary impairment on available-for-sale debt securities will be replaced with an allowance approach. The Company has engaged a third-party vendor solution and is currently in the implementation phase and evaluating the appropriate models, loan pools and assumptions to be utilized. The project team anticipates running parallel models during 2019 to refine its processes and procedures. For additional information on the ALLL, see Note 3. Note 1. Nature of Operations and Summary of Significant Accounting Policies (continued) ASU 2016-02 - 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. The Company has lease agreements for which the amendments will require the recognition of 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. An entity is permitted to elect not to restate its comparative periods in the period of adoption when transitioning to ASC Topic 842 and the Company expects to make this election. As a result, a cumulative-effect adjustment to retained earnings will be recognized as of the effective date. In addition, the Company expects to make the following elections: 1) to not use hindsight in determining lease terms and in assessing impairment of right-of-use assets; 2) to use the practical expedient package, which would require no reassessment of whether existing contracts are or contain leases as well as no reassessment of lease classification for existing leases; 3) to account for lease and nonlease components together as a single combined lease component; and 4) to exclude short-term leases from ASC Topic 842 guidance. When the Company adopts these amendments on January 1, 2019, the Company expects to recognize a right-of-use asset and related lease liability on the Company’s statement of financial condition of $36,042,000 and $37,384,000 , respectively. The Company has finalized its review of the amendments and has updated its accounting policies and procedures.

Debt Securities (Tables)

Debt Securities (Tables)	12 Months Ended
	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Amortized cost, gross unrealized gains and losses and the fair value of debt securities	The following tables present the amortized cost, the gross unrealized gains and losses and the fair value of the Company’s debt securities: December 31, 2018 Amortized Cost Gross Unrealized Fair Value (Dollars in thousands) Gains Losses Available-for-sale U.S. government and federal agency $ 23,757 54 (162 ) 23,649 U.S. government sponsored enterprises 120,670 52 (514 ) 120,208 State and local governments 844,636 18,936 (11,322 ) 852,250 Corporate bonds 292,052 378 (1,613 ) 290,817 Residential mortgage-backed securities 808,537 628 (16,250 ) 792,915 Commercial mortgage-backed securities 490,868 3,312 (2,356 ) 491,824 Total available-for-sale 2,580,520 23,360 (32,217 ) 2,571,663 Held-to-maturity State and local governments 297,915 1,380 (11,039 ) 288,256 Total held-to-maturity 297,915 1,380 (11,039 ) 288,256 Total debt securities $ 2,878,435 24,740 (43,256 ) 2,859,919 Note 2. Debt Securities (continued) 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 debt securities $ 2,419,817 42,779 (24,267 ) 2,438,329
Amortized cost and fair value of debt securities by contractual maturity	The following table presents the amortized cost and fair value of available-for-sale and held-to-maturity debt securities by contractual maturity at December 31, 2018 . Actual maturities may differ from expected or contractual maturities since issuers have the right to prepay obligations with or without prepayment penalties. December 31, 2018 Available-for-Sale Held-to-Maturity (Dollars in thousands) Amortized Cost Fair Value Amortized Cost Fair Value Due within one year $ 141,771 141,356 — — Due after one year through five years 316,311 314,777 6,457 6,527 Due after five years through ten years 311,194 314,961 75,204 74,100 Due after ten years 511,839 515,830 216,254 207,629 1,281,115 1,286,924 297,915 288,256 Mortgage-backed securities 1 1,299,405 1,284,739 — — Total $ 2,580,520 2,571,663 297,915 288,256 ______________________________ 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 debt securities and associated gains and losses	Proceeds from sales and calls of debt 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 debt securities $ 265,587 280,783 212,140 Gross realized gains 1 443 3,369 2,459 Gross realized losses 1 (455 ) (4,005 ) (3,794 ) Held-to-maturity Proceeds from calls of debt securities 79,000 23,020 25,405 Gross realized gains 1 101 204 97 Gross realized losses 1 (1,202 ) (228 ) (225 ) ______________________________ 1 The gain or loss on the sale or call of each debt security is determined by the specific identification method.
Summary of debt securities with an unrealized loss position	Debt securities with an unrealized loss position are summarized as follows: December 31, 2018 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 $ 4,287 (27 ) 10,519 (135 ) 14,806 (162 ) U.S. government sponsored enterprises 43,400 (103 ) 35,544 (411 ) 78,944 (514 ) State and local governments 72,080 (922 ) 232,244 (10,400 ) 304,324 (11,322 ) Corporate bonds 119,111 (937 ) 114,800 (676 ) 233,911 (1,613 ) Residential mortgage-backed securities 132,405 (833 ) 537,202 (15,417 ) 669,607 (16,250 ) Commercial mortgage-backed securities 73,118 (402 ) 86,504 (1,954 ) 159,622 (2,356 ) Total available-for-sale $ 444,401 (3,224 ) 1,016,813 (28,993 ) 1,461,214 (32,217 ) Held-to-maturity State and local governments $ 87,392 (2,778 ) 126,226 (8,261 ) 213,618 (11,039 ) Total held-to-maturity $ 87,392 (2,778 ) 126,226 (8,261 ) 213,618 (11,039 ) Note 2. Debt Securities (continued) 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 )

Loans Receivable, Net (Tables)

Loans Receivable, Net (Tables)	12 Months Ended
	Dec. 31, 2018
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 $ 887,742 720,728 Commercial loans Real estate 4,657,561 3,577,139 Other commercial 1,911,171 1,579,353 Total 6,568,732 5,156,492 Consumer and other loans Home equity 544,688 457,918 Other consumer 286,387 242,686 Total 831,075 700,604 Loans receivable 8,287,549 6,577,824 Allowance for loan and lease losses (131,239 ) (129,568 ) Loans receivable, net $ 8,156,310 6,448,256 Net deferred origination (fees) costs included in loans receivable $ (5,685 ) (2,643 ) Net purchase accounting (discounts) premiums included in loans receivable $ (25,172 ) (16,325 ) Weighted-average interest rate on loans (tax-equivalent) 4.97 % 4.81 %
Summary of the activity in the ALLL	The following tables summarize the activity in the ALLL by loan class: Year ended December 31, 2018 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Balance at beginning of period $ 129,568 10,798 68,515 39,303 6,204 4,748 Provision for loan losses 9,953 474 4,343 1,916 (471 ) 3,691 Charge-offs (17,807 ) (728 ) (3,469 ) (5,045 ) (210 ) (8,355 ) Recoveries 9,525 87 3,059 1,986 288 4,105 Balance at end of period $ 131,239 10,631 72,448 38,160 5,811 4,189 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
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 loan class: December 31, 2018 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Loans receivable Individually evaluated for impairment $ 108,788 12,685 68,837 20,975 3,497 2,794 Collectively evaluated for impairment 8,178,761 875,057 4,588,724 1,890,196 541,191 283,593 Total loans receivable $ 8,287,549 887,742 4,657,561 1,911,171 544,688 286,387 ALLL Individually evaluated for impairment $ 3,223 83 568 2,313 39 220 Collectively evaluated for impairment 128,016 10,548 71,880 35,847 5,772 3,969 Total ALLL $ 131,239 10,631 72,448 38,160 5,811 4,189 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
Loan portfolio aging analysis	The following tables present an aging analysis of the recorded investment in loans by loan class: December 31, 2018 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Accruing loans 30-59 days past due $ 24,312 5,251 9,477 4,282 3,213 2,089 Accruing loans 60-89 days past due 9,255 860 3,231 3,838 735 591 Accruing loans 90 days or more past due 2,018 788 — 492 428 310 Non-accrual loans 47,252 8,021 27,264 8,619 2,575 773 Total past due and non-accrual loans 82,837 14,920 39,972 17,231 6,951 3,763 Current loans receivable 8,204,712 872,822 4,617,589 1,893,940 537,737 282,624 Total loans receivable $ 8,287,549 887,742 4,657,561 1,911,171 544,688 286,387 Note 3. Loans Receivable, Net (continued) 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
Summary of the impaired loans	The following tables disclose information related to impaired loans by loan class: At or for the Year ended December 31, 2018 (Dollars in thousands) Total Residential Real Estate Commercial Real Estate Other Commercial Home Equity Other Consumer Loans with a specific valuation allowance Recorded balance $ 19,197 1,957 9,345 7,268 120 507 Unpaid principal balance 19,491 2,220 9,345 7,268 120 538 Specific valuation allowance 3,223 83 568 2,313 39 220 Average balance 19,519 2,686 8,498 7,081 82 1,172 Loans without a specific valuation allowance Recorded balance 89,591 10,728 59,492 13,707 3,377 2,287 Unpaid principal balance 107,486 11,989 71,300 17,689 3,986 2,522 Average balance 106,747 10,269 73,889 17,376 3,465 1,748 Total Recorded balance 108,788 12,685 68,837 20,975 3,497 2,794 Unpaid principal balance 126,977 14,209 80,645 24,957 4,106 3,060 Specific valuation allowance 3,223 83 568 2,313 39 220 Average balance 126,266 12,955 82,387 24,457 3,547 2,920 Note 3. Loans Receivable, Net (continued) 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
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, 2018 (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 25 4 8 10 2 1 Pre-modification recorded balance $ 21,995 724 12,901 7,813 252 305 Post-modification recorded balance $ 21,881 724 12,787 7,813 252 305 TDRs that subsequently defaulted Number of loans 1 1 — — — — Recorded balance $ 47 47 — — — — Note 3. Loans Receivable, Net (continued) 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 — — 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 — —

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2018
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, 2018 December 31, 2017 Land $ 47,511 31,370 Buildings and construction in progress 231,854 182,592 Furniture, fixtures and equipment 90,030 83,177 Leasehold improvements 9,370 8,085 Accumulated depreciation (137,237 ) (127,876 ) Net premises and equipment $ 241,528 177,348
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, 2018 are as follows: (Dollars in thousands) Capital Leases Operating Leases Total Years ending December 31, 2019 $ 92 3,192 3,284 2020 92 2,682 2,774 2021 7 2,145 2,152 2022 — 1,427 1,427 2023 — 943 943 Thereafter — 5,352 5,352 Total minimum lease payments 191 15,741 15,932 Less: Amount representing interest 10 Present value of minimum lease payments 181 Less: Current portion of obligations under capital leases 84 Long-term portion of obligations under capital leases $ 97

Other Intangible Assets and G_2

Other Intangible Assets and Goodwill (Tables)	12 Months Ended
	Dec. 31, 2018
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 $ 62,977 21,649 21,943 Accumulated amortization (13,735 ) (7,465 ) (9,596 ) Net carrying value $ 49,242 14,184 12,347 Aggregate amortization expense $ 6,270 2,494 2,970 Estimated amortization expense for the years ending December 31, 2019 $ 6,768 2020 6,598 2021 6,407 2022 6,187 2023 5,711
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 $ 177,811 147,053 140,638 Acquisitions and adjustments 111,775 30,758 6,415 Net carrying value at end of period $ 289,586 177,811 147,053

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	12 Months Ended
	Dec. 31, 2018
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 $ 80,123 57,796 Accrued interest receivable 96 94 Other assets 45,779 15,885 Total assets $ 125,998 73,775 Liabilities Other borrowed funds $ 14,527 7,964 Accrued interest payable 1 1 Other liabilities 125 98 Total liabilities $ 14,653 8,063
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, 2018 December 31, 2017 December 31, Amortization expense $ 4,926 2,507 1,125 Tax credits and other tax benefits recognized 6,550 3,827 1,515

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2018
Deposits [Abstract]
Scheduled maturities of time deposits	The scheduled maturities of time deposits are as follows: (Dollars in thousands) Amount Years ending December 31, 2019 $ 634,197 2020 147,320 2021 71,500 2022 28,138 2023 20,310 Thereafter 19 $ 901,484

Borrowings (Tables)

Borrowings (Tables)	12 Months Ended
	Dec. 31, 2018
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, 2018 Remaining Contractual Maturity of the Agreements (Dollars in thousands) Overnight and Continuous Up to 30 Days Total Residential mortgage-backed securities $ 328,174 — 328,174 Commercial mortgage-backed securities 66,339 1,638 67,977 Total $ 394,513 1,638 396,151 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
Maturities of FHLB Advances	The scheduled maturities of FHLB advances consist of the following: December 31, 2018 December 31, 2017 (Dollars in thousands) Amount Weighted Rate Amount Weighted Rate Maturing within one year $ 285,847 2.63 % $ 200,869 1.64 % Maturing one year through two years 1,572 3.50 % 887 2.05 % Maturing two years through three years 150,370 3.77 % 1,651 3.58 % Maturing three years through four years 918 5.25 % 148,721 2.69 % Maturing four years through five years 204 5.45 % 945 5.25 % Thereafter 1,264 4.82 % 922 5.42 % Total $ 440,175 3.03 % $ 353,995 2.11 %

Subordinated Debentures (Tables

Subordinated Debentures (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Instruments [Abstract]
Summary of Subordinated Debentures	The Company’s subordinated debentures are reflected in the table below. The amounts include fair value adjustments from acquisitions. December 31, 2018 Rate Structure Maturity Date (Dollars in thousands) Balance Rate Subordinated debentures owed to trust subsidiaries First Company Statutory Trust 2001 $ 3,332 5.827 % 3 month LIBOR plus 3.30% 07/31/2031 First Company Statutory Trust 2003 2,452 6.072 % 3 month LIBOR plus 3.25% 03/26/2033 Glacier Capital Trust II 46,393 5.186 % 3 month LIBOR plus 2.75% 04/07/2034 Citizens (ID) Statutory Trust I 5,155 5.438 % 3 month LIBOR plus 2.65% 06/17/2034 Glacier Capital Trust III 36,083 3.726 % 3 month LIBOR plus 1.29% 04/07/2036 Glacier Capital Trust IV 30,928 4.358 % 3 month LIBOR plus 1.57% 09/15/2036 Bank of the San Juans Bancorporation Trust I 1,935 4.558 % 3 month LIBOR plus 1.82% 03/01/2037 Total subordinated debentures owed to trust subsidiaries 126,278 Tier 2 subordinated debentures 7,773 6.625 % Fixed 10/01/2025 Total subordinated debentures $ 134,051

Derivatives and Hedging Activ_2

Derivatives and Hedging Activities (Tables)	12 Months Ended
	Dec. 31, 2018
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, 2018 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 $ 3,286 444 (1,643 ) Amount of loss reclassified from OCI to interest expense (2,334 ) (4,892 ) (6,417 )
Offsetting Assets	The following table discloses the offsetting of financial assets and interest rate swap derivative assets. December 31, 2018 December 31, 2017 (Dollars in thousands) Gross Amount of Recognized Assets Gross Amount Offset in the Statements of Financial Position Net Amounts of Assets Presented in the Statements of Financial Position Gross Amount of Recognized Assets Gross Amount Offset in the Statements of Financial Position Net Amounts of Assets Presented in the Statements of Financial Position Interest rate swaps $ 139 (139 ) — — — —
Offsetting Liabilities	The following table discloses the offsetting of financial liabilities and interest rate swap derivative liabilities. December 31, 2018 December 31, 2017 (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 $ 3,908 (139 ) 3,769 9,389 — 9,389

Regulatory Capital (Tables)

Regulatory Capital (Tables)	12 Months Ended
	Dec. 31, 2018
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, 2018 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 $ 1,437,889 14.70 % $ 782,453 8.00 % N/A N/A Glacier Bank 1,401,991 14.35 % 781,430 8.00 % $ 976,787 10.00 % Tier 1 capital (to risk-weighted assets) Consolidated 1,308,017 13.37 % 586,840 6.00 % N/A N/A Glacier Bank 1,279,778 13.10 % 586,072 6.00 % 781,430 8.00 % Common Equity Tier 1 (to risk-weighted assets) Consolidated 1,183,517 12.10 % 440,130 4.50 % N/A N/A Glacier Bank 1,279,778 13.10 % 439,554 4.50 % 634,911 6.50 % Tier 1 capital (to average assets) Consolidated 1,308,017 11.35 % 461,130 4.00 % N/A N/A Glacier Bank 1,279,778 11.08 % 462,072 4.00 % 577,590 5.00 % December 31, 2017 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 $ 1,232,089 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 % ______________________________ N/A - Not applicable

Stock-based Compensation Plan (

Stock-based Compensation Plan (Tables)	12 Months Ended
	Dec. 31, 2018
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, 2018 : Restricted Stock Weighted- Average Grant Date Fair Value Non-vested at December 31, 2017 183,178 $ 29.84 Granted 114,366 39.92 Vested (111,273 ) 29.82 Forfeited (4,288 ) 37.64 Non-vested at December 31, 2018 181,983 36.03

Other Expenses (Tables)

Other Expenses (Tables)	12 Months Ended
	Dec. 31, 2018
Other Expenses [Abstract]
Schedule of Other Expenses	Other expenses consists of the following: Years ended (Dollars in thousands) December 31, December 31, December 31, Consulting and outside services $ 7,219 5,331 5,683 Mergers and acquisition expenses 6,618 2,130 1,732 Debit card expenses 5,104 7,189 8,462 Telephone 4,487 3,891 3,828 Employee expenses 4,412 4,160 3,573 Business development 4,172 3,333 3,286 VIE amortization and other expenses 3,618 3,109 2,702 Loan expenses 3,462 3,080 3,611 Printing and supplies 3,264 2,661 2,800 Postage 3,104 2,684 2,785 Legal fees 1,763 1,106 1,027 Accounting and audit fees 1,456 1,848 1,613 Checking and operating expenses 1,234 1,760 2,942 ATM expenses 1,217 1,720 880 Other 3,164 3,043 2,646 Total other expenses $ 54,294 47,045 47,570

Federal and State Income Taxes

Federal and State Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
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 $ 21,510 29,555 30,461 State 11,960 9,183 9,283 Total current income tax expense 33,470 38,738 39,744 Deferred 1 Federal 5,372 22,246 (70 ) State 1,489 3,641 (12 ) Total deferred income tax expense (benefit) 6,861 25,887 (82 ) Total income tax expense $ 40,331 64,625 39,662 ______________________________ 1 Includes tax benefit of operating loss carryforwards of $443,000 , $644,000 and $571,000 for the years ended December 31, 2018 , 2017 , and 2016 , respectively.
Summary of effective tax rate	Combined federal and state income tax expense differs from that computed at the federal statutory corporate income tax rate as follows: Years ended December 31, December 31, December 31, Federal statutory rate 21.0 % 35.0 % 35.0 % State taxes, net of federal income tax benefit 4.8 % 4.6 % 3.8 % Tax rate change — % 10.9 % — % Tax-exempt interest income (5.0 )% (10.5 )% (12.2 )% Tax credits (4.2 )% (3.2 )% (2.1 )% Other, net 1.6 % (1.1 )% 0.2 % Effective income tax rate 18.2 % 35.7 % 24.7 %
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 $ 33,313 32,890 Acquisition fair market value adjustments 6,380 4,139 Deferred compensation 6,251 5,640 Employee benefits 2,939 2,615 Net operating loss carryforwards 2,525 2,841 Available-for-sale debt securities 2,244 — Interest rate swap agreements 955 2,379 Other real estate owned 801 5,126 Other 4,798 3,673 Total gross deferred tax assets 60,206 59,303 Deferred tax liabilities Intangibles (12,667 ) (4,161 ) Depreciation of premises and equipment (10,776 ) (2,863 ) Deferred loan costs (6,436 ) (5,854 ) FHLB stock dividends (2,722 ) (2,602 ) Debt modification costs (1,173 ) (1,591 ) Available-for-sale debt securities — (1,707 ) Other (2,868 ) (2,181 ) Total gross deferred tax liabilities (36,642 ) (20,959 ) Net deferred tax asset $ 23,564 38,344
Income tax return jurisdictions and years subject to examination	The following schedule summarizes the years that remain subject to examination as of December 31, 2018 : Years ended December 31, Federal 2015, 2016 and 2017 Montana 2015, 2016 and 2017 Idaho 2015, 2016 and 2017 Utah 2015, 2016 and 2017 Colorado 2014, 2015, 2016 and 2017 Arizona 2017

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Loss (Tables)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Activity within Accumulated Other Comprehensive Loss, Net of Tax	The following table illustrates the activity within accumulated other comprehensive loss by component, net of tax: (Dollars in thousands) Gains (Losses) on Available-For-Sale Debt Securities Losses on Derivatives Used for Cash Flow Hedges Total Balance at January 1, 2016 $ 13,935 (11,946 ) 1,989 Other comprehensive loss before reclassifications (13,113 ) (1,006 ) (14,119 ) Reclassification adjustments for losses 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 losses included in net income 391 3,005 3,396 Reclassifications 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 ) Other comprehensive (loss) income before reclassifications (11,653 ) 2,453 (9,200 ) Reclassification adjustments for losses included in net income 9 1,743 1,752 Net current period other comprehensive (loss) income (11,644 ) 4,196 (7,448 ) Balance at December 31, 2018 $ (6,613 ) (2,814 ) (9,427 ) ______________________________ 1 Reclassifications were due to the one-time revaluation of the net deferred tax asset as a result of the Tax Act. For additional information on the Tax Act, see Note 15.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2018
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 $ 181,878 116,377 121,131 Average outstanding shares - basic 83,603,515 77,537,664 76,278,463 Add: dilutive restricted stock awards and stock options 73,670 69,941 63,373 Average outstanding shares - diluted 83,677,185 77,607,605 76,341,836 Basic earnings per share $ 2.18 1.50 1.59 Diluted earnings per share $ 2.17 1.50 1.59

Parent Holding Company Inform_2

Parent Holding Company Information (Condensed) (Tables)	12 Months Ended
	Dec. 31, 2018
Condensed Financial Information 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 $ 22,000 9,304 Interest bearing cash deposits 42,299 38,420 Cash and cash equivalents 64,299 47,724 Other assets 12,639 8,871 Investment in subsidiaries 1,612,115 1,281,392 Total assets $ 1,689,053 1,337,987 Liabilities and Stockholders’ Equity Dividends payable $ 25,726 265 Subordinated debentures 134,051 126,135 Other liabilities 13,422 12,530 Total liabilities 173,199 138,930 Common stock 845 780 Paid-in capital 1,051,253 797,997 Retained earnings 473,183 402,259 Accumulated other comprehensive loss (9,427 ) (1,979 ) Total stockholders’ equity 1,515,854 1,199,057 Total liabilities and stockholders’ equity $ 1,689,053 1,337,987
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 $ 153,574 119,000 108,350 Gain on sale of investments — 3 — Intercompany charges for services 16,523 14,299 12,248 Other income 1,284 225 311 Total income 171,381 133,527 120,909 Expenses Compensation and employee benefits 20,873 17,864 15,665 Other operating expenses 12,201 10,425 7,701 Total expenses 33,074 28,289 23,366 Income before income tax benefit and equity in undistributed net income of subsidiaries 138,307 105,238 97,543 Income tax benefit 3,773 2,983 4,040 Income before equity in undistributed net income of subsidiaries 142,080 108,221 101,583 Equity in undistributed net income of subsidiaries 39,798 8,156 19,548 Net Income $ 181,878 116,377 121,131 Comprehensive Income $ 174,430 122,131 111,760
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 $ 181,878 116,377 121,131 Adjustments to reconcile net income to net cash provided by operating activities: Subsidiary income in excess of dividends distributed (39,798 ) (8,156 ) (19,548 ) Amortization of purchase accounting adjustments 13 143 143 Gain on sale of investments — (3 ) — Stock-based compensation, net of tax benefits 1,219 1,460 804 Net change in other assets and other liabilities (3,222 ) 5,051 (297 ) Net cash provided by operating activities 140,090 114,872 102,233 Investing Activities Sales of available-for-sale securities — 27 — Net (increase) decrease of premises and equipment (300 ) (79 ) 771 Proceeds from sale of non-marketable equity securities — 114 55 Equity contributions to subsidiaries (24,989 ) (17,565 ) (3,475 ) Net cash used in investing activities (25,289 ) (17,503 ) (2,649 ) Financing Activities Net increase in other borrowed funds (11,543 ) — — Cash dividends paid (85,493 ) (111,720 ) (84,040 ) Tax withholding payments for stock-based compensation (1,190 ) (1,531 ) (600 ) Net cash used in financing activities (98,226 ) (113,251 ) (84,640 ) Net increase (decrease) in cash, cash equivalents and restricted cash 16,575 (15,882 ) 14,944 Cash, cash equivalents and restricted cash at beginning of year 47,724 63,606 48,662 Cash, cash equivalents and restricted cash at end of year $ 64,299 47,724 63,606

Unaudited Quarterly Financial_2

Unaudited Quarterly Financial Data (Condensed) (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Summarized unaudited quarterly financial data	Summarized unaudited quarterly financial data is as follows: Quarters ended 2018 (Dollars in thousands, except per share data) March 31 June 30 September 30 December 31 Interest income $ 103,066 117,715 122,905 125,310 Interest expense 7,774 9,161 9,160 9,436 Net interest income 95,292 108,554 113,745 115,874 Provision for loan losses 795 4,718 3,194 1,246 Net interest income after provision for loan losses 94,497 103,836 110,551 114,628 Non-interest income 26,086 31,828 32,416 28,494 Non-interest expense 73,627 81,795 82,829 81,876 Income before income taxes 46,956 53,869 60,138 61,246 Federal and state income tax expense 8,397 9,485 10,802 11,647 Net income $ 38,559 44,384 49,336 49,599 Basic earnings per share $ 0.48 0.53 0.58 0.59 Diluted earnings per share $ 0.48 0.52 0.58 0.59 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

Fair Value of Assets and Liab_2

Fair Value of Assets and Liabilities (Tables)	12 Months Ended
	Dec. 31, 2018
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, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Debt securities, available-for-sale U.S. government and federal agency $ 23,649 — 23,649 — U.S. government sponsored enterprises 120,208 — 120,208 — State and local governments 852,250 — 852,250 — Corporate bonds 290,817 — 290,817 — Residential mortgage-backed securities 792,915 — 792,915 — Commercial mortgage-backed securities 491,824 — 491,824 — Loans held for sale, at fair value 33,156 — 33,156 — Total assets measured at fair value on a recurring basis $ 2,604,819 — 2,604,819 — Interest rate swaps $ 3,769 — 3,769 — Total liabilities measured at fair value on a recurring basis $ 3,769 — 3,769 — 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, 2017 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Debt 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, at fair value 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 —
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, 2018 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 $ 1,011 — — 1,011 Collateral-dependent impaired loans, net of ALLL 6,985 — — 6,985 Total assets measured at fair value on a non-recurring basis $ 7,996 — — 7,996 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
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 $ 1,011 Sales comparison approach Selling costs 8.0% - 15.0% (9.2%) Collateral-dependent impaired loans, net of ALLL $ 2,384 Sales comparison approach Selling costs 8.0% - 20.0% (9.9%) 4,601 Combined approach Selling costs 10.0% - 10.0% (10.0%) $ 6,985 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 $ 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 ______________________________ 1 The range for selling cost inputs represents reductions to the fair value of the assets.
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 not carried at fair value. Receivables and payables due in one year or less, equity securities without readily determinable fair values and deposits with no defined or contractual maturities are excluded. Fair Value Measurements At the End of the Reporting Period Using (Dollars in thousands) Carrying Amount December 31, 2018 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 $ 203,790 203,790 — — Debt securities, held-to-maturity 297,915 — 288,256 — Loans receivable, net of ALLL 8,156,310 — — 8,079,112 Total financial assets $ 8,658,015 203,790 288,256 8,079,112 Financial liabilities Term deposits $ 1,070,208 — 1,069,777 — FHLB advances 440,175 — 439,615 — Repurchase agreements and other borrowed funds 410,859 — 410,859 — Subordinated debentures 134,051 — 120,302 — Total financial liabilities $ 2,055,293 — 2,040,553 — 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, 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 — — Debt securities, held-to-maturity 648,313 — 660,086 — Loans receivable, net of ALLL 6,448,256 — 6,219,515 114,771 Total financial assets $ 7,296,573 200,004 6,879,601 114,771 Financial liabilities Term deposits $ 977,302 — 978,803 — FHLB advances 353,995 — 352,886 — Repurchase agreements and other borrowed funds 370,797 — 370,797 — Subordinated debentures 126,135 — 98,023 — Total financial liabilities $ 1,828,229 — 1,800,509 —

Contingencies and Commitments (

Contingencies and Commitments (Tables)	12 Months Ended
	Dec. 31, 2018
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 $ 1,948,516 1,565,112 Letters of credit 45,263 40,082 Total outstanding commitments $ 1,993,779 1,605,194

Mergers and Acquisitions (Table

Mergers and Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2018
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 FSB, Collegiate and Foothills acquisitions: (Dollars in thousands) FSB February 28, 2018 Collegiate January 31, 2018 Foothills April 30, 2017 Fair value of consideration transferred Fair value of Company shares issued, net of equity issuance costs $ 181,043 69,764 46,673 Cash consideration for outstanding shares — 16,265 17,342 Effective settlement of a pre-existing relationship — 10,054 — Total fair value of consideration transferred 181,043 96,083 64,015 Recognized amounts of identifiable assets acquired and liabilities assumed Identifiable assets acquired Cash and cash equivalents 24,397 93,136 13,251 Debt securities 271,865 42,177 25,420 Loans receivable 627,767 354,252 292,529 Core deposit intangible 1 31,053 10,275 4,331 Accrued income and other assets 78,274 15,911 19,699 Total identifiable assets acquired 1,033,356 515,751 355,230 Liabilities assumed Deposits 877,586 437,171 296,760 Borrowings 2 36,880 12,509 22,800 Accrued expenses and other liabilities 14,175 5,435 2,264 Total liabilities assumed 928,641 455,115 321,824 Total identifiable net assets 104,715 60,636 33,406 Goodwill recognized $ 76,328 35,447 30,609 ______________________________ 1 The core deposit intangible for each acquisition was determined to have an estimated life of 10 years . 2 Borrowings assumed with the FSB acquisition include Tier 2 subordinated debentures of $7,903,000 .
Unaudited Pro Forma Summary of the Company as if the 2018 Acquisitions had Occurred at the Beginning of the Period	The following unaudited pro forma summary presents consolidated information of the Company as if the FSB and Collegiate acquisitions had occurred on January 1, 2017: Years ended (Dollars in thousands) December 31, December 31, Net interest income and non-interest income $ 560,979 520,634 Net income 177,267 138,042
Unaudited Pro Forma Summary of the Company as if the 2017 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

Nature of Operations and Summ_3

Nature of Operations and Summary of Significant Accounting Policies (Details Textual)	12 Months Ended
	Dec. 31, 2018USD ($)quarterstepreporting_unitdivisionoperating_segment	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Number of Bank Divisions | division	14
Number of Operating Segments | operating_segment	1
Maximum Period of Original Maturity to be Included in Cash and Cash Equivalents	3 months
Federal Reserve Balance or Cash on Hand Required	$ 53,626,000
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
Revenue from Contracts with Customers	$ 76,664,000	$ 69,808,000	$ 64,722,000
Impairment losses on receivables related to contracts with customers	$ 0	0
Percentage of likelihood for term more likely than not as it relates to income taxes	50.00%
Transfer of debt securities from held-to-maturity to available-for-sale	$ 270,331,000	$ 0	$ 0
Accounting Standards Update 2017-12
Transfer of debt securities from held-to-maturity to available-for-sale	$ 270,331,000
Accounting Standards Update 2014-09
Number of Steps to Achieve Core Revenue Recognition Principal | step	5
Accounting Standards Update 2017-08
Effect of cumulative change on retained earnings from applying new accounting pronouncement	$ 24,102,000
Accounting Standards Update 2016-02
Effect of cumulative change on assets from applying new accounting pronouncement	36,042,000
Effect of cumulative change on liabilities from applying new accounting pronouncement	$ 37,384,000
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

Amortized Cost, Gross Unrealize

Amortized Cost, Gross Unrealized Gains and Losses and Fair Value of Investment Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Available-for-sale
Amortized Cost	$ 2,580,520	$ 1,771,504
Gross Unrealized Gains	23,360	22,433
Gross Unrealized Losses	(32,217)	(15,694)
Total	2,571,663	1,778,243
Held-to-maturity
Amortized Cost	297,915	648,313
Gross Unrealized Gains	1,380	20,346
Gross Unrealized Losses	(11,039)	(8,573)
Fair Value	288,256	660,086
Debt Securities, Available-for-sale and Held-to-maturity [Abstract]
Amortized Cost	2,878,435	2,419,817
Gross Unrealized Gains	24,740	42,779
Gross Unrealized Losses	(43,256)	(24,267)
Fair Value	2,859,919	2,438,329
U.S. government and federal agency
Available-for-sale
Amortized Cost	23,757	31,216
Gross Unrealized Gains	54	54
Gross Unrealized Losses	(162)	(143)
Total	23,649	31,127
U.S. government sponsored enterprises
Available-for-sale
Amortized Cost	120,670	19,195
Gross Unrealized Gains	52	0
Gross Unrealized Losses	(514)	(104)
Total	120,208	19,091
State and local governments
Available-for-sale
Amortized Cost	844,636	614,366
Gross Unrealized Gains	18,936	20,299
Gross Unrealized Losses	(11,322)	(5,164)
Total	852,250	629,501
Held-to-maturity
Amortized Cost	297,915	648,313
Gross Unrealized Gains	1,380	20,346
Gross Unrealized Losses	(11,039)	(8,573)
Fair Value	288,256	660,086
Corporate bonds
Available-for-sale
Amortized Cost	292,052	216,443
Gross Unrealized Gains	378	802
Gross Unrealized Losses	(1,613)	(483)
Total	290,817	216,762
Residential mortgage backed securities
Available-for-sale
Amortized Cost	808,537	785,960
Gross Unrealized Gains	628	1,253
Gross Unrealized Losses	(16,250)	(7,930)
Total	792,915	779,283
Commercial mortgage backed securities
Available-for-sale
Amortized Cost	490,868	104,324
Gross Unrealized Gains	3,312	25
Gross Unrealized Losses	(2,356)	(1,870)
Total	$ 491,824	$ 102,479

Debt Securities Maturity Schedu

Debt Securities Maturity Schedule (Details) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Available-for-Sale, Amortized Cost
Due within one year		$ 141,771
Due after one year through five years		316,311
Due after five years through ten years		311,194
Due after ten years		511,839
Total before mortgage-backed securities		1,281,115
Amortized Cost		2,580,520	$ 1,771,504
Available-for-Sale, Fair Value
Due with one year		141,356
Due after one year through five years		314,777
Due after five years through ten years		314,961
Due after ten years		515,830
Total before mortgage-backed securities		1,286,924
Total		2,571,663	1,778,243
Held-to-Maturity, Amortized Cost
Due within one year		0
Due after one year through five years		6,457
Due after five years through ten years		75,204
Due after ten years		216,254
Total before mortgage-backed securities		297,915
Amortized Cost		297,915	648,313
Held-to-Maturity, Fair Value
Due within one year		0
Due after one year through five years		6,527
Due after five years through ten years		74,100
Due after ten years		207,629
Total before mortgage-backed securities		288,256
Total		288,256	$ 660,086
Mortgage-backed securities
Available-for-Sale, Amortized Cost
Mortgage-backed securities	[1]	1,299,405
Available-for-Sale, Fair Value
Mortgage-backed securities	[1]	1,284,739
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 Debt Se

Gain or Loss on Sale of Debt Securities (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Available-for-sale
Proceeds from Sales and Calls of Debt Securities		$ 265,587	$ 280,783	$ 212,140
Gross realized gains	[1]	443	3,369	2,459
Gross realized losses	[1]	(455)	(4,005)	(3,794)
Held-to-maturity
Proceeds from calls of debt securities		79,000	23,020	25,405
Gross realized gains	[1]	101	204	97
Gross realized losses	[1]	$ (1,202)	$ (228)	$ (225)
[1]	The gain or loss on the sale or call of each debt security is determined by the specific identification method.

Debt Securities with an Unreali

Debt Securities with an Unrealized Loss Position (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Available-for-sale, Fair Value
Less than 12 Months	$ 444,401	$ 586,721
12 Months or More	1,016,813	484,508
Total	1,461,214	1,071,229
Available-for-sale, Unrealized Loss
Less than 12 Months	(3,224)	(4,533)
12 Months or Longer	(28,993)	(11,161)
Total	(32,217)	(15,694)
Held-to-maturity, Fair Value
Less than 12 Months	87,392	21,207
12 Months or More	126,226	105,486
Total	213,618	126,693
Held-to-maturity, Unrealized Loss
Less than 12 Months	(2,778)	(186)
12 Months or More	(8,261)	(8,387)
Total	(11,039)	(8,573)
U.S. government and federal agency
Available-for-sale, Fair Value
Less than 12 Months	4,287	1,208
12 Months or More	10,519	13,179
Total	14,806	14,387
Available-for-sale, Unrealized Loss
Less than 12 Months	(27)	(5)
12 Months or Longer	(135)	(138)
Total	(162)	(143)
U.S. government sponsored enterprises
Available-for-sale, Fair Value
Less than 12 Months	43,400	14,926
12 Months or More	35,544	3,425
Total	78,944	18,351
Available-for-sale, Unrealized Loss
Less than 12 Months	(103)	(56)
12 Months or Longer	(411)	(48)
Total	(514)	(104)
State and local governments
Available-for-sale, Fair Value
Less than 12 Months	72,080	61,126
12 Months or More	232,244	121,181
Total	304,324	182,307
Available-for-sale, Unrealized Loss
Less than 12 Months	(922)	(689)
12 Months or Longer	(10,400)	(4,475)
Total	(11,322)	(5,164)
Held-to-maturity, Fair Value
Less than 12 Months	87,392	21,207
12 Months or More	126,226	105,486
Total	213,618	126,693
Held-to-maturity, Unrealized Loss
Less than 12 Months	(2,778)	(186)
12 Months or More	(8,261)	(8,387)
Total	(11,039)	(8,573)
Corporate bonds
Available-for-sale, Fair Value
Less than 12 Months	119,111	99,636
12 Months or More	114,800	29,034
Total	233,911	128,670
Available-for-sale, Unrealized Loss
Less than 12 Months	(937)	(264)
12 Months or Longer	(676)	(219)
Total	(1,613)	(483)
Residential mortgage backed securities
Available-for-sale, Fair Value
Less than 12 Months	132,405	372,175
12 Months or More	537,202	254,721
Total	669,607	626,896
Available-for-sale, Unrealized Loss
Less than 12 Months	(833)	(3,050)
12 Months or Longer	(15,417)	(4,880)
Total	(16,250)	(7,930)
Commercial mortgage backed securities
Available-for-sale, Fair Value
Less than 12 Months	73,118	37,650
12 Months or More	86,504	62,968
Total	159,622	100,618
Available-for-sale, Unrealized Loss
Less than 12 Months	(402)	(469)
12 Months or Longer	(1,954)	(1,401)
Total	$ (2,356)	$ (1,870)

Debt Securities (Details Textua

Debt Securities (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Transfer of debt securities from held-to-maturity to available-for-sale	$ 270,331,000	$ 0	$ 0
Debt securities pledged as collateral	1,333,455,000	1,447,808,000
Other-than-temporary impairment on debt securities	$ 0	$ 0

Loans Receivable, Net Summary o

Loans Receivable, Net Summary of Loans Receivable (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Summary of Loans Receivable
Loans receivable	$ 8,287,549	$ 6,577,824
Allowance for loan and lease losses	(131,239)	(129,568)
Loans receivable, net	8,156,310	6,448,256
Net deferred origination (fees) costs included in loans receivable	(5,685)	(2,643)
Net purchase accounting (discounts) premiums included in loans receivable	$ (25,172)	$ (16,325)
Weighted-average interest rate on loans (tax-equivalent)	4.97%	4.81%
Residential Real Estate | Residential Real Estate
Summary of Loans Receivable
Loans receivable	$ 887,742	$ 720,728
Allowance for loan and lease losses	(10,631)	(10,798)
Commercial
Summary of Loans Receivable
Loans receivable	6,568,732	5,156,492
Commercial | Commercial Real Estate
Summary of Loans Receivable
Loans receivable	4,657,561	3,577,139
Allowance for loan and lease losses	(72,448)	(68,515)
Commercial | Other Commercial
Summary of Loans Receivable
Loans receivable	1,911,171	1,579,353
Allowance for loan and lease losses	(38,160)	(39,303)
Consumer and Other
Summary of Loans Receivable
Loans receivable	831,075	700,604
Consumer and Other | Home Equity
Summary of Loans Receivable
Loans receivable	544,688	457,918
Allowance for loan and lease losses	(5,811)	(6,204)
Consumer and Other | Other Consumer
Summary of Loans Receivable
Loans receivable	286,387	242,686
Allowance for loan and lease losses	$ (4,189)	$ (4,748)

ALLL Activity (Details)

ALLL Activity (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allowance for loan and lease losses
Balance at beginning of period				$ 129,568				$ 129,572	$ 129,568	$ 129,572	$ 129,697
Provision for loan losses	$ 1,246	$ 3,194	$ 4,718	795	$ 2,886	$ 3,327	$ 3,013	1,598	9,953	10,824	2,333
Charge-offs									(17,807)	(19,331)	(11,496)
Recoveries									9,525	8,503	9,038
Balance at end of period	131,239				129,568				131,239	129,568	129,572
Residential Real Estate | Residential Real Estate
Allowance for loan and lease losses
Balance at beginning of period				10,798				12,436	10,798	12,436	14,427
Provision for loan losses									474	(1,521)	(1,734)
Charge-offs									(728)	(199)	(464)
Recoveries									87	82	207
Balance at end of period	10,631				10,798				10,631	10,798	12,436
Commercial | Commercial Real Estate
Allowance for loan and lease losses
Balance at beginning of period				68,515				65,773	68,515	65,773	67,877
Provision for loan losses									4,343	7,152	(2,686)
Charge-offs									(3,469)	(6,188)	(3,082)
Recoveries									3,059	1,778	3,664
Balance at end of period	72,448				68,515				72,448	68,515	65,773
Commercial | Other Commercial
Allowance for loan and lease losses
Balance at beginning of period				39,303				37,823	39,303	37,823	32,525
Provision for loan losses									1,916	2,545	5,164
Charge-offs									(5,045)	(2,856)	(1,778)
Recoveries									1,986	1,791	1,912
Balance at end of period	38,160				39,303				38,160	39,303	37,823
Consumer and Other | Home Equity
Allowance for loan and lease losses
Balance at beginning of period				6,204				7,572	6,204	7,572	8,998
Provision for loan losses									(471)	(1,103)	(520)
Charge-offs									(210)	(489)	(1,185)
Recoveries									288	224	279
Balance at end of period	5,811				6,204				5,811	6,204	7,572
Consumer and Other | Other Consumer
Allowance for loan and lease losses
Balance at beginning of period				$ 4,748				$ 5,968	4,748	5,968	5,870
Provision for loan losses									3,691	3,751	2,109
Charge-offs									(8,355)	(9,599)	(4,987)
Recoveries									4,105	4,628	2,976
Balance at end of period	$ 4,189				$ 4,748				$ 4,189	$ 4,748	$ 5,968

Loans Receivable, Net ALLL and

Loans Receivable, Net ALLL and Loans Receivable Summary (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Loans Receivable and Allowance for Loan and Lease Losses
Individually evaluated for impairment	$ 108,788	$ 119,994
Collectively evaluated for impairment	8,178,761	6,457,830
Total loans receivable	8,287,549	6,577,824
Individually evaluated for impairment	3,223	5,223
Collectively evaluated for impairment	128,016	124,345
Total ALLL	131,239	129,568
Residential Real Estate | Residential Real Estate
Loans Receivable and Allowance for Loan and Lease Losses
Individually evaluated for impairment	12,685	12,399
Collectively evaluated for impairment	875,057	708,329
Total loans receivable	887,742	720,728
Individually evaluated for impairment	83	246
Collectively evaluated for impairment	10,548	10,552
Total ALLL	10,631	10,798
Commercial
Loans Receivable and Allowance for Loan and Lease Losses
Total loans receivable	6,568,732	5,156,492
Commercial | Commercial Real Estate
Loans Receivable and Allowance for Loan and Lease Losses
Individually evaluated for impairment	68,837	77,536
Collectively evaluated for impairment	4,588,724	3,499,603
Total loans receivable	4,657,561	3,577,139
Individually evaluated for impairment	568	500
Collectively evaluated for impairment	71,880	68,015
Total ALLL	72,448	68,515
Commercial | Other Commercial
Loans Receivable and Allowance for Loan and Lease Losses
Individually evaluated for impairment	20,975	23,032
Collectively evaluated for impairment	1,890,196	1,556,321
Total loans receivable	1,911,171	1,579,353
Individually evaluated for impairment	2,313	3,851
Collectively evaluated for impairment	35,847	35,452
Total ALLL	38,160	39,303
Consumer and Other
Loans Receivable and Allowance for Loan and Lease Losses
Total loans receivable	831,075	700,604
Consumer and Other | Home Equity
Loans Receivable and Allowance for Loan and Lease Losses
Individually evaluated for impairment	3,497	3,755
Collectively evaluated for impairment	541,191	454,163
Total loans receivable	544,688	457,918
Individually evaluated for impairment	39	56
Collectively evaluated for impairment	5,772	6,148
Total ALLL	5,811	6,204
Consumer and Other | Other Consumer
Loans Receivable and Allowance for Loan and Lease Losses
Individually evaluated for impairment	2,794	3,272
Collectively evaluated for impairment	283,593	239,414
Total loans receivable	286,387	242,686
Individually evaluated for impairment	220	570
Collectively evaluated for impairment	3,969	4,178
Total ALLL	$ 4,189	$ 4,748

Loans Receivable Aging Analysis

Loans Receivable Aging Analysis (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Loan portfolio aging analysis
Non-accrual loans	$ 47,252	$ 44,833
Total past due and non-accrual loans	82,837	88,597
Current loans receivable	8,204,712	6,489,227
Total loans receivable	8,287,549	6,577,824
Accruing loans 30 to 59 days past due
Loan portfolio aging analysis
Past due loans	24,312	26,375
Accruing loans 60 to 89 days past due
Loan portfolio aging analysis
Past due loans	9,255	11,312
Accruing loans 90 days or more past due
Loan portfolio aging analysis
Past due loans	2,018	6,077
Residential Real Estate | Residential Real Estate
Loan portfolio aging analysis
Non-accrual loans	8,021	4,924
Total past due and non-accrual loans	14,920	14,336
Current loans receivable	872,822	706,392
Total loans receivable	887,742	720,728
Residential Real Estate | Residential Real Estate | Accruing loans 30 to 59 days past due
Loan portfolio aging analysis
Past due loans	5,251	6,252
Residential Real Estate | Residential Real Estate | Accruing loans 60 to 89 days past due
Loan portfolio aging analysis
Past due loans	860	794
Residential Real Estate | Residential Real Estate | Accruing loans 90 days or more past due
Loan portfolio aging analysis
Past due loans	788	2,366
Commercial
Loan portfolio aging analysis
Total loans receivable	6,568,732	5,156,492
Commercial | Commercial Real Estate
Loan portfolio aging analysis
Non-accrual loans	27,264	27,331
Total past due and non-accrual loans	39,972	45,853
Current loans receivable	4,617,589	3,531,286
Total loans receivable	4,657,561	3,577,139
Commercial | Commercial Real Estate | Accruing loans 30 to 59 days past due
Loan portfolio aging analysis
Past due loans	9,477	12,546
Commercial | Commercial Real Estate | Accruing loans 60 to 89 days past due
Loan portfolio aging analysis
Past due loans	3,231	5,367
Commercial | Commercial Real Estate | Accruing loans 90 days or more past due
Loan portfolio aging analysis
Past due loans	0	609
Commercial | Other Commercial
Loan portfolio aging analysis
Non-accrual loans	8,619	8,298
Total past due and non-accrual loans	17,231	18,407
Current loans receivable	1,893,940	1,560,946
Total loans receivable	1,911,171	1,579,353
Commercial | Other Commercial | Accruing loans 30 to 59 days past due
Loan portfolio aging analysis
Past due loans	4,282	3,634
Commercial | Other Commercial | Accruing loans 60 to 89 days past due
Loan portfolio aging analysis
Past due loans	3,838	3,502
Commercial | Other Commercial | Accruing loans 90 days or more past due
Loan portfolio aging analysis
Past due loans	492	2,973
Consumer and Other
Loan portfolio aging analysis
Total loans receivable	831,075	700,604
Consumer and Other | Home Equity
Loan portfolio aging analysis
Non-accrual loans	2,575	3,338
Total past due and non-accrual loans	6,951	6,467
Current loans receivable	537,737	451,451
Total loans receivable	544,688	457,918
Consumer and Other | Home Equity | Accruing loans 30 to 59 days past due
Loan portfolio aging analysis
Past due loans	3,213	2,142
Consumer and Other | Home Equity | Accruing loans 60 to 89 days past due
Loan portfolio aging analysis
Past due loans	735	987
Consumer and Other | Home Equity | Accruing loans 90 days or more past due
Loan portfolio aging analysis
Past due loans	428	0
Consumer and Other | Other Consumer
Loan portfolio aging analysis
Non-accrual loans	773	942
Total past due and non-accrual loans	3,763	3,534
Current loans receivable	282,624	239,152
Total loans receivable	286,387	242,686
Consumer and Other | Other Consumer | Accruing loans 30 to 59 days past due
Loan portfolio aging analysis
Past due loans	2,089	1,801
Consumer and Other | Other Consumer | Accruing loans 60 to 89 days past due
Loan portfolio aging analysis
Past due loans	591	662
Consumer and Other | Other Consumer | Accruing loans 90 days or more past due
Loan portfolio aging analysis
Past due loans	$ 310	$ 129

Impaired Loans (Details)

Impaired Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Summary of the impaired loans by portfolio class of loans
Loans with a Specific Valuation Allowance, Recorded Balance	$ 19,197	$ 17,689
Loans with a Specific Valuation Allowance, Unpaid Principal Balance	19,491	18,400
Specific valuation allowance	3,223	5,223
Loans with a Specific Valuation Allowance, Average Balance	19,519	18,986
Loans without a Specific Valuation Allowance, Recorded Balance	89,591	102,305
Loans without a Specific Valuation Allowance, Unpaid Principal Balance	107,486	122,833
Loans without a Specific Valuation Allowance, Average Balance	106,747	107,945
Recorded balance	108,788	119,994
Unpaid principal balance	126,977	141,233
Average balance	126,266	126,931
Residential Real Estate | Residential Real Estate
Summary of the impaired loans by portfolio class of loans
Loans with a Specific Valuation Allowance, Recorded Balance	1,957	2,978
Loans with a Specific Valuation Allowance, Unpaid Principal Balance	2,220	3,046
Specific valuation allowance	83	246
Loans with a Specific Valuation Allowance, Average Balance	2,686	2,928
Loans without a Specific Valuation Allowance, Recorded Balance	10,728	9,421
Loans without a Specific Valuation Allowance, Unpaid Principal Balance	11,989	10,380
Loans without a Specific Valuation Allowance, Average Balance	10,269	9,834
Recorded balance	12,685	12,399
Unpaid principal balance	14,209	13,426
Average balance	12,955	12,762
Commercial | Commercial Real Estate
Summary of the impaired loans by portfolio class of loans
Loans with a Specific Valuation Allowance, Recorded Balance	9,345	4,545
Loans with a Specific Valuation Allowance, Unpaid Principal Balance	9,345	4,573
Specific valuation allowance	568	500
Loans with a Specific Valuation Allowance, Average Balance	8,498	5,851
Loans without a Specific Valuation Allowance, Recorded Balance	59,492	72,991
Loans without a Specific Valuation Allowance, Unpaid Principal Balance	71,300	89,839
Loans without a Specific Valuation Allowance, Average Balance	73,889	76,427
Recorded balance	68,837	77,536
Unpaid principal balance	80,645	94,412
Average balance	82,387	82,278
Commercial | Other Commercial
Summary of the impaired loans by portfolio class of loans
Loans with a Specific Valuation Allowance, Recorded Balance	7,268	8,183
Loans with a Specific Valuation Allowance, Unpaid Principal Balance	7,268	8,378
Specific valuation allowance	2,313	3,851
Loans with a Specific Valuation Allowance, Average Balance	7,081	8,477
Loans without a Specific Valuation Allowance, Recorded Balance	13,707	14,849
Loans without a Specific Valuation Allowance, Unpaid Principal Balance	17,689	16,931
Loans without a Specific Valuation Allowance, Average Balance	17,376	15,129
Recorded balance	20,975	23,032
Unpaid principal balance	24,957	25,309
Average balance	24,457	23,606
Consumer and Other | Home Equity
Summary of the impaired loans by portfolio class of loans
Loans with a Specific Valuation Allowance, Recorded Balance	120	186
Loans with a Specific Valuation Allowance, Unpaid Principal Balance	120	199
Specific valuation allowance	39	56
Loans with a Specific Valuation Allowance, Average Balance	82	359
Loans without a Specific Valuation Allowance, Recorded Balance	3,377	3,569
Loans without a Specific Valuation Allowance, Unpaid Principal Balance	3,986	4,098
Loans without a Specific Valuation Allowance, Average Balance	3,465	4,734
Recorded balance	3,497	3,755
Unpaid principal balance	4,106	4,297
Average balance	3,547	5,093
Consumer and Other | Other Consumer
Summary of the impaired loans by portfolio class of loans
Loans with a Specific Valuation Allowance, Recorded Balance	507	1,797
Loans with a Specific Valuation Allowance, Unpaid Principal Balance	538	2,204
Specific valuation allowance	220	570
Loans with a Specific Valuation Allowance, Average Balance	1,172	1,371
Loans without a Specific Valuation Allowance, Recorded Balance	2,287	1,475
Loans without a Specific Valuation Allowance, Unpaid Principal Balance	2,522	1,585
Loans without a Specific Valuation Allowance, Average Balance	1,748	1,821
Recorded balance	2,794	3,272
Unpaid principal balance	3,060	3,789
Average balance	$ 2,920	$ 3,192

Troubled Debt Restructurings (D

Troubled Debt Restructurings (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)Loan	Dec. 31, 2017USD ($)Loan	Dec. 31, 2016USD ($)Loan
Troubled Debt Restructurings
Troubled Debt Restructurings, Number of Loans | Loan	25	32	34
Troubled Debt Restructurings, Pre-Modification Recorded Balance	$ 21,995	$ 41,521	$ 22,907
Troubled Debt Restructurings, Post-Modification Recorded Balance	$ 21,881	$ 38,838	$ 22,848
TDRs that Subsequently Defaulted, Number of Loans | Loan	1	1	1
TDRs that Subsequently Defaulted, Recorded Balance	$ 47	$ 18	$ 6
Residential Real Estate | Residential Real Estate
Troubled Debt Restructurings
Troubled Debt Restructurings, Number of Loans | Loan	4	5	0
Troubled Debt Restructurings, Pre-Modification Recorded Balance	$ 724	$ 841	$ 0
Troubled Debt Restructurings, Post-Modification Recorded Balance	$ 724	$ 841	$ 0
TDRs that Subsequently Defaulted, Number of Loans | Loan	1	0	0
TDRs that Subsequently Defaulted, Recorded Balance	$ 47	$ 0	$ 0
Commercial | Commercial Real Estate
Troubled Debt Restructurings
Troubled Debt Restructurings, Number of Loans | Loan	8	13	10
Troubled Debt Restructurings, Pre-Modification Recorded Balance	$ 12,901	$ 31,109	$ 8,454
Troubled Debt Restructurings, Post-Modification Recorded Balance	$ 12,787	$ 28,426	$ 8,415
TDRs that Subsequently Defaulted, Number of Loans | Loan	0	0	0
TDRs that Subsequently Defaulted, Recorded Balance	$ 0	$ 0	$ 0
Commercial | Other Commercial
Troubled Debt Restructurings
Troubled Debt Restructurings, Number of Loans | Loan	10	11	21
Troubled Debt Restructurings, Pre-Modification Recorded Balance	$ 7,813	$ 9,403	$ 14,183
Troubled Debt Restructurings, Post-Modification Recorded Balance	$ 7,813	$ 9,403	$ 14,166
TDRs that Subsequently Defaulted, Number of Loans | Loan	0	1	1
TDRs that Subsequently Defaulted, Recorded Balance	$ 0	$ 18	$ 6
Consumer and Other | Home Equity
Troubled Debt Restructurings
Troubled Debt Restructurings, Number of Loans | Loan	2	2	3
Troubled Debt Restructurings, Pre-Modification Recorded Balance	$ 252	$ 158	$ 270
Troubled Debt Restructurings, Post-Modification Recorded Balance	$ 252	$ 158	$ 267
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	1	0
Troubled Debt Restructurings, Pre-Modification Recorded Balance	$ 305	$ 10	$ 0
Troubled Debt Restructurings, Post-Modification Recorded Balance	$ 305	$ 10	$ 0
TDRs that Subsequently Defaulted, Number of Loans | Loan	0	0	0
TDRs that Subsequently Defaulted, Recorded Balance	$ 0	$ 0	$ 0

Loans Receivable, Net (Details

Loans Receivable, Net (Details Textual)	12 Months Ended
	Dec. 31, 2018USD ($)portfolio_segment	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Loans Receivable
Number of segments in the Company's loan portfolio | portfolio_segment	3
Variable rate loans	$ 5,181,912,000
Fixed rate loans	3,105,637,000
Loans pledged as collateral	$ 4,483,373,000
Percentage of consolidated stockholders equity exceeding which no borrower had outstanding loans or commitments	10.00%
Loans serviced for others	$ 181,281,000	$ 4,042,000
Aggregate amount of loans outstanding to related parties	59,528,000	82,350,000
New loans to related parties	17,830,000
Repayments of loans by related parties	38,276,000
Effect of changes in composition of related party loans	(2,376,000)
Interest income that would have been recorded on non-accrual loans	2,340,000	2,162,000	$ 2,364,000
TDR With Pre Modification Loan Balance for Which Oreo Was Received	6,793,000	5,987,000	5,331,000
Consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings are in process	350,000	743,000
OREO Secured by Residential Real Estate	698,000	893,000
Additional unfunded commitments on TDRs	5,335,000	1,960,000
Charge-offs on TDRs	$ 1,685,000	$ 2,984,000	$ 557,000

Premises and Equipment, Net of

Premises and Equipment, Net of Accumulated Depreciation (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Premises and Equipment, Net of Accumulated Depreciation
Accumulated depreciation	$ (137,237)	$ (127,876)
Premises and equipment, net	241,528	177,348
Land
Premises and Equipment, Net of Accumulated Depreciation
Premises and equipment, gross	47,511	31,370
Buildings and construction in progress
Premises and Equipment, Net of Accumulated Depreciation
Premises and equipment, gross	231,854	182,592
Furniture, fixtures and equipment
Premises and Equipment, Net of Accumulated Depreciation
Premises and equipment, gross	90,030	83,177
Leasehold improvements
Premises and Equipment, Net of Accumulated Depreciation
Premises and equipment, gross	$ 9,370	$ 8,085

Premises and Equipment Future M

Premises and Equipment Future Minimum Rental Commitments under Operating and Capital Leases (Details) $ in Thousands	Dec. 31, 2018USD ($)
Capital Leases
For the Year Ended December 31, 2019	$ 92
For the Year Ended December 31, 2020	92
For the Year Ended December 31, 2021	7
For the Year Ended December 31, 2022	0
For the Year Ended December 31, 2023	0
Thereafter	0
Total minimum lease payments	191
Less: Amount representing interest	10
Present value of minimum lease payments	181
Less: Current portion of obligations under capital leases	84
Long-term portion of obligations under capital leases	97
Operating Leases
For the Year Ended December 31, 2019	3,192
For the Year Ended December 31, 2020	2,682
For the Year Ended December 31, 2021	2,145
For the Year Ended December 31, 2022	1,427
For the Year Ended December 31, 2023	943
Thereafter	5,352
Total Minimum Lease Payments	15,741
Total
For the Year Ended December 31, 2019	3,284
For the Year Ended December 31, 2020	2,774
For the Year Ended December 31, 2021	2,152
For the Year Ended December 31, 2022	1,427
For the Year Ended December 31, 2023	943
Thereafter	5,352
Total Minimum Lease Payments	$ 15,932

Premises and Equipment (Details

Premises and Equipment (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Premises and Equipment
Depreciation expense	$ 16,019,000	$ 14,758,000	$ 15,294,000
Total rent expense	4,224,000	3,629,000	3,255,000
Related party rent expense	$ 12,000	$ 164,000	$ 153,000

Net Carrying Value of Core Depo

Net Carrying Value of Core Deposit Intangibles (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net Core Deposit Intangibles and Aggregate Amortization Expense
Net carrying value	$ 49,242	$ 14,184
Aggregate amortization expense	6,270	2,494	$ 2,970
Core Deposits Intangibles
Net Core Deposit Intangibles and Aggregate Amortization Expense
Gross carrying value	62,977	21,649	21,943
Accumulated amortization	(13,735)	(7,465)	(9,596)
Net carrying value	49,242	14,184	12,347
Aggregate amortization expense	6,270	$ 2,494	$ 2,970
Estimated Amortization Expense
For the year ending December 31, 2019	6,768
For the year ending December 31, 2020	6,598
For the year ending December 31, 2021	6,407
For the year ending December 31, 2022	6,187
For the year ending December 31, 2023	$ 5,711

Changes in the Carrying Value o

Changes in the Carrying Value of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill Roll Forward
Net carrying value at beginning of period	$ 177,811	$ 147,053	$ 140,638
Acquisitions and adjustments	111,775	30,758	6,415
Net carrying value at end of period	$ 289,586	$ 177,811	$ 147,053

Other Intangible Assets and G_3

Other Intangible Assets and Goodwill Other Intangible Assets and Goodwill (Details Textual) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets
Accumulated impairment charge	$ 40,159,000	$ 40,159,000
Core Deposits Intangibles
Finite-Lived Intangible Assets
Core Deposit Intangibles Acquired	$ 41,328,000	$ 4,331,000	$ 762,000

Variable Interest Entities VIE

Variable Interest Entities VIE Carrying Amounts Included in Financial Statements (Details) - Consolidated VIEs - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Consolidated VIEs
Assets	$ 125,998	$ 73,775
Liabilities	14,653	8,063
Loans Receivable
Consolidated VIEs
Assets	80,123	57,796
Accrued Interest Receivable
Consolidated VIEs
Assets	96	94
Other Assets
Consolidated VIEs
Assets	45,779	15,885
Other Borrowed Funds
Consolidated VIEs
Liabilities	14,527	7,964
Accrued Interest Payable
Consolidated VIEs
Liabilities	1	1
Other Liabilities
Consolidated VIEs
Liabilities	$ 125	$ 98

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, 2018	Dec. 31, 2017	Dec. 31, 2016
Investments in Qualified Affordable Housing Projects
Amortization expense	$ 4,926	$ 2,507	$ 1,125
Tax credits and other tax benefits recognized	$ 6,550	$ 3,827	$ 1,515

Variable Interest Entities (Det

Variable Interest Entities (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Variable Interest Entities
Unfunded contingent commitments	$ 11,484,000
Impairment losses	0	$ 0	$ 0
Other assets
Variable Interest Entities
Carrying value of equity investments in LIHTCs	$ 35,112,000	$ 9,169,000
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, 2018USD ($)
Maturities of Time Deposits
For the year ending December 31, 2019	$ 634,197
For the year ending December 31, 2020	147,320
For the year ending December 31, 2021	71,500
For the year ending December 31, 2022	28,138
For the year ending December 31, 2023	20,310
Thereafter	19
Total	$ 901,484

Deposits (Details Textual)

Deposits (Details Textual) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Deposits
FDIC Insurance limit	$ 250,000
Time deposits that meet or exceed FDIC Insurance limit	244,999,000	$ 193,962,000
Overdraft demand deposits reclassified as loans	5,992,000	4,402,000
Deposits with related parties	$ 26,260,000	$ 25,641,000

Borrowings Summary of Repurchas

Borrowings Summary of Repurchase Agreements (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Securities Sold Under Agreements to Repurchase
Repurchase Agreements	$ 396,151	$ 362,573
Overnight and Continuous
Securities Sold Under Agreements to Repurchase
Repurchase Agreements	394,513	362,573
Up to 30 Days
Securities Sold Under Agreements to Repurchase
Repurchase Agreements	1,638	0
Residential mortgage backed securities
Securities Sold Under Agreements to Repurchase
Repurchase Agreements	328,174	360,751
Residential mortgage backed securities | Overnight and Continuous
Securities Sold Under Agreements to Repurchase
Repurchase Agreements	328,174	360,751
Residential mortgage backed securities | Up to 30 Days
Securities Sold Under Agreements to Repurchase
Repurchase Agreements	0	0
Commercial mortgage backed securities
Securities Sold Under Agreements to Repurchase
Repurchase Agreements	67,977	1,822
Commercial mortgage backed securities | Overnight and Continuous
Securities Sold Under Agreements to Repurchase
Repurchase Agreements	66,339	1,822
Commercial mortgage backed securities | Up to 30 Days
Securities Sold Under Agreements to Repurchase
Repurchase Agreements	$ 1,638	$ 0

Scheduled Maturities of FHLB Ad

Scheduled Maturities of FHLB Advances (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
FHLB Advances
Maturing within one year, Amount	$ 285,847	$ 200,869
Maturing within one year, Weighted rate	2.63%	1.64%
Maturing one year through two years, Amount	$ 1,572	$ 887
Maturing one year through two years, Weighted rate	3.50%	2.05%
Maturing two years through three years, Amount	$ 150,370	$ 1,651
Maturing two years through three years, Weighted rate	3.77%	3.58%
Maturing three years through four years, Amount	$ 918	$ 148,721
Maturing three years through four years, Weighted rate	5.25%	2.69%
Maturing four years through five years, Amount	$ 204	$ 945
Maturing four years through five years, Weighted rate	5.45%	5.25%
Thereafter, Amount	$ 1,264	$ 922
Thereafter, Weighted rate	4.82%	5.42%
Total, Amount	$ 440,175	$ 353,995
Total, Weighted rate	3.03%	2.11%

Borrowings (Details Textual)

Borrowings (Details Textual) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Debt Disclosure [Abstract]
Repurchase Agreements	$ 396,151,000	$ 362,573,000
Securities Pledged for Repurchase Agreements	511,294,000	$ 475,601,000
Lines of credit	$ 230,000,000

Subordinated Debentures (Detail

Subordinated Debentures (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Terms of Subordinated Debentures
Balance	$ 134,051	$ 126,135
Subordinated debentures owed to trust subsidiaries
Terms of Subordinated Debentures
Balance	126,278
Tier 2 subordinated debentures
Terms of Subordinated Debentures
Balance	$ 7,773
Rate at December 31, 2018	6.625%
First Company Statutory Trust 2001 | Subordinated debentures owed to trust subsidiaries
Terms of Subordinated Debentures
Balance	$ 3,332
Rate at December 31, 2018	5.827%
LIBOR Rate Spread	3.30%
First Company Statutory Trust 2003 | Subordinated debentures owed to trust subsidiaries
Terms of Subordinated Debentures
Balance	$ 2,452
Rate at December 31, 2018	6.072%
LIBOR Rate Spread	3.25%
Glacier Capital Trust II | Subordinated debentures owed to trust subsidiaries
Terms of Subordinated Debentures
Balance	$ 46,393
Rate at December 31, 2018	5.186%
LIBOR Rate Spread	2.75%
Citizens (ID) Statutory Trust I | Subordinated debentures owed to trust subsidiaries
Terms of Subordinated Debentures
Balance	$ 5,155
Rate at December 31, 2018	5.438%
LIBOR Rate Spread	2.65%
Glacier Capital Trust III | Subordinated debentures owed to trust subsidiaries
Terms of Subordinated Debentures
Balance	$ 36,083
Rate at December 31, 2018	3.726%
LIBOR Rate Spread	1.29%
Glacier Capital Trust IV | Subordinated debentures owed to trust subsidiaries
Terms of Subordinated Debentures
Balance	$ 30,928
Rate at December 31, 2018	4.358%
LIBOR Rate Spread	1.57%
Bank of the San Juans Bancorporation Trust I | Subordinated debentures owed to trust subsidiaries
Terms of Subordinated Debentures
Balance	$ 1,935
Rate at December 31, 2018	4.558%
LIBOR Rate Spread	1.82%

Subordinated Debentures (Deta_2

Subordinated Debentures (Details Textual)	12 Months Ended
	Dec. 31, 2018
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
Number of Years Before Allowed to Prepay Tier 2 Subordinated Debt	5

Interest Rate Swap Summary (Det

Interest Rate Swap Summary (Details) $ in Thousands	Dec. 31, 2018USD ($)
Interest Rate Swap One
Interest rate swap derivative financial instruments
Forecasted Notional Amount	$ 160,000
Fixed Interest Rate	3.378%
Interest Rate Swap Two
Interest rate swap derivative financial instruments
Forecasted Notional Amount	$ 100,000
Fixed Interest Rate	2.498%

Derivatives and Hedging Activ_3

Derivatives and Hedging Activities Interest Rate Swap Gains or Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pre-Tax Gains or Losses
Amount of gain (loss) recognized in OCI	$ 3,286	$ 444	$ (1,643)
Interest Rate Swaps | Interest Expense
Pre-Tax Gains or Losses
Amount of loss reclassified from OCI to interest expense	(2,334)	(4,892)	(6,417)
Interest Rate Swaps | Other Comprehensive Income
Pre-Tax Gains or Losses
Amount of gain (loss) recognized in OCI	$ 3,286	$ 444	$ (1,643)

Derivatives and Hedging Activ_4

Derivatives and Hedging Activities Offsetting Assets (Details) - Interest Rate Swaps - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Offsetting Derivative Assets
Gross Amounts of Recognized Assets	$ 139	$ 0
Gross Amounts Offset in the Statements of Financial Position	(139)	0
Net Amounts of Assets Presented in the Statements of Financial Position	$ 0	$ 0

Derivatives and Hedging Activ_5

Derivatives and Hedging Activities Offsetting Liabilities (Details) - Interest Rate Swaps - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Offsetting Derivative Liabilities
Gross Amounts of Recognized Liabilities	$ 3,908	$ 9,389
Gross Amounts Offset in the Statements of Financial Position	(139)	0
Net Amounts of Liabilities Presented in the Statements of Financial Position	$ 3,769	$ 9,389

Derivatives and Hedging Activ_6

Derivatives and Hedging Activities Derivatives and Hedging Activities (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest rate swap derivative financial instruments
Debt securities pledged as collateral	$ 1,333,455,000	$ 1,447,808,000
Interest Rate Lock Commitments
Interest rate swap derivative financial instruments
Off-balance Sheet Commitments	59,974,000	67,861,000
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 Swaps
Interest rate swap derivative financial instruments
Interest rate expense recorded on interest rate swap	8,013,000	$ 8,013,000	$ 8,035,000
Unrealized loss to be reclassified within twelve months	1,663,000
Debt securities pledged as collateral	4,730,000
Collateral pledged from counterparties to the Company	0
Forward commitments to sell TBA securities
Interest rate swap derivative financial instruments
Forecasted Notional Amount	$ 40,750,000

Regulatory Capital (Details)

Regulatory Capital (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Total capital (to risk-weighted assets)
Actual, Amount	$ 1,437,889	$ 1,232,089
Actual, Ratio	14.70%	15.64%
Minimum capital requirement, Amount	$ 782,453	$ 630,109
Minimum capital requirement, Ratio	8.00%	8.00%
Tier 1 capital (to risk-weighted assets)
Actual, Amount	$ 1,308,017	$ 1,133,125
Actual, Ratio	13.37%	14.39%
Minimum capital requirement, Amount	$ 586,840	$ 472,582
Minimum capital requirement, Ratio	6.00%	6.00%
Common Equity Tier 1 (to risk-weighted assets)
Actual, Amount	$ 1,183,517	$ 1,009,276
Actual, Ratio	12.10%	12.81%
Minimum capital requirement, Amount	$ 440,130	$ 354,437
Minimum capital requirement, Ratio	4.50%	4.50%
Tier 1 capital (to average assets)
Actual, Amount	$ 1,308,017	$ 1,133,125
Actual, Ratio	11.35%	11.90%
Minimum capital requirement, Amount	$ 461,130	$ 380,770
Minimum capital requirement, Ratio	4.00%	4.00%
Glacier Bank
Total capital (to risk-weighted assets)
Actual, Amount	$ 1,401,991	$ 1,182,509
Actual, Ratio	14.35%	15.04%
Minimum capital requirement, Amount	$ 781,430	$ 628,823
Minimum capital requirement, Ratio	8.00%	8.00%
Well capitalized requirement, Amount	$ 976,787	$ 786,029
Well capitalized requirement, Ratio	10.00%	10.00%
Tier 1 capital (to risk-weighted assets)
Actual, Amount	$ 1,279,778	$ 1,083,744
Actual, Ratio	13.10%	13.79%
Minimum capital requirement, Amount	$ 586,072	$ 471,617
Minimum capital requirement, Ratio	6.00%	6.00%
Well capitalized requirement, Amount	$ 781,430	$ 628,823
Well capitalized requirement, Ratio	8.00%	8.00%
Common Equity Tier 1 (to risk-weighted assets)
Actual, Amount	$ 1,279,778	$ 1,083,744
Actual, Ratio	13.10%	13.79%
Minimum capital requirement, Amount	$ 439,554	$ 353,713
Minimum capital requirement, Ratio	4.50%	4.50%
Well capitalized requirement, Amount	$ 634,911	$ 510,919
Well capitalized requirement, Ratio	6.50%	6.50%
Tier 1 capital (to average assets)
Actual, Amount	$ 1,279,778	$ 1,083,744
Actual, Ratio	11.08%	11.47%
Minimum capital requirement, Amount	$ 462,072	$ 377,809
Minimum capital requirement, Ratio	4.00%	4.00%
Well capitalized requirement, Amount	$ 577,590	$ 472,261
Well capitalized requirement, Ratio	5.00%	5.00%

Regulatory Capital (Details Tex

Regulatory Capital (Details Textual)	Dec. 31, 2018
Common Equity Tier 1 (to risk-weighted assets)
Capital Conservation Buffer for 2018	1.875%

Stock-based Compensation Plan S

Stock-based Compensation Plan Summary of Restricted Stock Award Activity (Details) - Restricted Stock	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Restricted stock award activity for the year
Restricted Stock Non-Vested, Beginning Balance | shares	183,178
Restricted Stock, Granted | shares	114,366
Restricted Stock, Vested | shares	(111,273)
Restricted Stock, Forfeited | shares	(4,288)
Restricted Stock Non-Vested, Ending Balance | shares	181,983
Weighted-average grant date fair value
Restricted stock, weighted average grant date fair value, beginning balance | $ / shares	$ 29.84
Restricted stock, granted, weighted average grant date fair value | $ / shares	39.92
Restricted stock, vested, weighted average grant date fair value | $ / shares	29.82
Restricted stock, forfeited, weighted average grant date fair value | $ / shares	37.64
Restricted stock, weighted average grant date fair value, ending balance | $ / shares	$ 36.03

Stock-based Compensation Plan_2

Stock-based Compensation Plan (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Stock-based Compensation Plans
Shares available to grant to employees and directors	2,139,518
Restricted Stock
Restricted Stock Awards
Compensation expense related to awards	$ 3,703,000	$ 3,764,000	$ 2,870,000
Income tax benefit related to awards	934,000	1,452,000	1,112,000
Unrecognized compensation expense	$ 4,013,000
Unrecognized compensation expense, recognized over weighted-average period	2 years
Fair value of awards that vested	$ 3,319,000	3,746,000	2,624,000
Tax benefit of awards that vested	$ 1,126,000	$ 1,998,000	$ 1,053,000
Average remaining contractual term on non-vested awards	10 months 24 days
Aggregate intrinsic value of non-vested awards	$ 7,210,000

Employee Benefit Plans (Details

Employee Benefit Plans (Details Textual)	12 Months Ended
	Dec. 31, 2018USD ($)quarterhouryear	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
401(k) and Profit Sharing Plan
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%
Cost of plan	$ 15,406,000	$ 10,100,000	$ 9,041,000
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	$ 4,037,000	3,224,000	2,946,000
401(k) and Profit Sharing Plan | 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 Plan | 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 Plan
401(k) and Profit Sharing Plans
Cost of plan	$ 502,000	481,000	431,000
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	$ 803,000	739,000	967,000
Credit earning rate as a percentage of return on equity	50.00%
Deferred Compensation Plan Acquired
401(k) and Profit Sharing Plans
Cost of plan	$ 801,000	588,000	632,000
Liability related to obligations of deferred compensation plans	13,651,000	11,275,000
Supplemental Employee Retirement Plan
401(k) and Profit Sharing Plans
Cost of plan	122,000	105,000	85,000
Company's contribution to the plan	$ 423,000	$ 287,000	$ 299,000
Credit earning rate as a percentage of return on equity	50.00%

Other Expenses (Details)

Other Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Other Expenses
Consulting and outside services	$ 7,219	$ 5,331	$ 5,683
Mergers and acquisition expenses	6,618	2,130	1,732
Debit card expenses	5,104	7,189	8,462
Telephone	4,487	3,891	3,828
Employee expenses	4,412	4,160	3,573
Business development	4,172	3,333	3,286
VIE amortization and other expenses	3,618	3,109	2,702
Loan expenses	3,462	3,080	3,611
Printing and supplies	3,264	2,661	2,800
Postage	3,104	2,684	2,785
Legal fees	1,763	1,106	1,027
Accounting and audit fees	1,456	1,848	1,613
Checking and operating expenses	1,234	1,760	2,942
ATM expenses	1,217	1,720	880
Other	3,164	3,043	2,646
Total other expenses	$ 54,294	$ 47,045	$ 47,570

Summary of Income Tax Expense (

Summary of Income Tax Expense (Details) - USD ($)		3 Months Ended								12 Months Ended
		Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current
Federal										$ 21,510,000	$ 29,555,000	$ 30,461,000
State										11,960,000	9,183,000	9,283,000
Total current income tax expense										33,470,000	38,738,000	39,744,000
Deferred
Federal	[1]									5,372,000	22,246,000	(70,000)
State	[1]									1,489,000	3,641,000	(12,000)
Total deferred income tax expense (benefit)	[1]									6,861,000	25,887,000	(82,000)
Total income tax expense		$ 11,647,000	$ 10,802,000	$ 9,485,000	$ 8,397,000	$ 31,327,000	$ 11,639,000	$ 11,905,000	$ 9,754,000	40,331,000	64,625,000	39,662,000
Tax benefit of operating loss carryforwards										$ 443,000	$ 644,000	$ 571,000
[1]	Includes tax benefit of operating loss carryforwards of $443,000, $644,000 and $571,000 for the years ended December 31, 2018, 2017, and 2016, respectively.

Summary of Effective Tax Rate (

Summary of Effective Tax Rate (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Effective income tax rate reconciliation
Federal statutory rate	21.00%	35.00%	35.00%
State taxes, net of federal income tax benefit	4.80%	4.60%	3.80%
Tax rate change	0.00%	10.90%	0.00%
Tax-exempt interest income	(5.00%)	(10.50%)	(12.20%)
Tax credits	(4.20%)	(3.20%)	(2.10%)
Other, net	1.60%	(1.10%)	0.20%
Effective tax rate	18.20%	35.70%	24.70%

Deferred Tax Assets and Deferre

Deferred Tax Assets and Deferred Tax Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets
Allowance for loan and lease losses	$ 33,313	$ 32,890
Acquisition fair market value adjustments	6,380	4,139
Deferred compensation	6,251	5,640
Employee benefits	2,939	2,615
Net operating loss carryforwards	2,525	2,841
Available-for-sale debt securities	2,244	0
Interest rate swap agreements	955	2,379
Other real estate owned	801	5,126
Other	4,798	3,673
Total gross deferred tax assets	60,206	59,303
Deferred tax liabilities
Intangibles	(12,667)	(4,161)
Depreciation of premises and equipment	(10,776)	(2,863)
Deferred loan costs	(6,436)	(5,854)
FHLB stock dividends	(2,722)	(2,602)
Debt modification costs	(1,173)	(1,591)
Available-for-sale debt securities	0	(1,707)
Other	(2,868)	(2,181)
Total gross deferred tax liabilities	(36,642)	(20,959)
Net deferred tax asset	$ 23,564	$ 38,344

Years Subject to Examination (D

Years Subject to Examination (Details)	12 Months Ended
	Dec. 31, 2018
Federal
Income Tax Examination
Income tax return jurisdictions and years that remain subject to examination	2015, 2016 and 2017
Montana
Income Tax Examination
Income tax return jurisdictions and years that remain subject to examination	2015, 2016 and 2017
Idaho
Income Tax Examination
Income tax return jurisdictions and years that remain subject to examination	2015, 2016 and 2017
Utah
Income Tax Examination
Income tax return jurisdictions and years that remain subject to examination	2015, 2016 and 2017
Colorado
Income Tax Examination
Income tax return jurisdictions and years that remain subject to examination	2014, 2015, 2016 and 2017
Arizona
Income Tax Examination
Income tax return jurisdictions and years that remain subject to examination	2,017

Federal and State Income Taxe_2

Federal and State Income Taxes (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
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	$ 9,337,000
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	$ 12,988,000
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 Comprehensi_3

Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Loss
Balance, beginning		$ (1,979)
Total other comprehensive (loss) income, net of tax		(7,448)	$ 5,754	$ (9,371)
Balance, end		(9,427)	(1,979)
Available-For-Sale Debt Securities
Accumulated Other Comprehensive Loss
Balance, beginning		5,031	1,639	13,935
Other comprehensive income (loss) before reclassification		(11,653)	2,110	(13,113)
Reclassification adjustments for losses included in net income		9	391	817
Reclassifications to retained earnings	[1]		891
Total other comprehensive (loss) income, net of tax		(11,644)	3,392	(12,296)
Balance, end		(6,613)	5,031	1,639
Derivatives Used for Cash Flow Hedges
Accumulated Other Comprehensive Loss
Balance, beginning		(7,010)	(9,021)	(11,946)
Other comprehensive income (loss) before reclassification		2,453	248	(1,006)
Reclassification adjustments for losses included in net income		1,743	3,005	3,931
Reclassifications to retained earnings	[1]		(1,242)
Total other comprehensive (loss) income, net of tax		4,196	2,011	2,925
Balance, end		(2,814)	(7,010)	(9,021)
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Loss
Balance, beginning		(1,979)	(7,382)	1,989
Other comprehensive income (loss) before reclassification		(9,200)	2,358	(14,119)
Reclassification adjustments for losses included in net income		1,752	3,396	4,748
Reclassifications to retained earnings	[1]		(351)
Total other comprehensive (loss) income, net of tax		(7,448)	5,403	(9,371)
Balance, end		$ (9,427)	$ (1,979)	$ (7,382)
[1]	Reclassifications were due to the one-time revaluation of the net deferred tax asset as a result of the Tax Act.

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Basic and Diluted Earnings Per Share
Net Income	$ 49,599	$ 49,336	$ 44,384	$ 38,559	$ 14,956	$ 36,479	$ 33,687	$ 31,255	$ 181,878	$ 116,377	$ 121,131
Average outstanding shares - basic									83,603,515	77,537,664	76,278,463
Add: dilutive restricted stock awards and stock options									73,670	69,941	63,373
Average outstanding shares - diluted									83,677,185	77,607,605	76,341,836
Basic earnings per share	$ 0.59	$ 0.58	$ 0.53	$ 0.48	$ 0.19	$ 0.47	$ 0.43	$ 0.41	$ 2.18	$ 1.50	$ 1.59
Diluted earnings per share	$ 0.59	$ 0.58	$ 0.52	$ 0.48	$ 0.19	$ 0.47	$ 0.43	$ 0.41	$ 2.17	$ 1.50	$ 1.59
Earnings Per Share
Restricted stock awards and stock options excluded from the diluted average outstanding share calculation									1,357	0	0

Condensed Statements of Financi

Condensed Statements of Financial Condition (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets
Cash on hand and in banks	$ 161,782	$ 139,948
Interest bearing cash deposits	42,008	60,056
Cash and cash equivalents	203,790	200,004
Other assets	76,651	37,047
Total assets	12,115,484	9,706,349
Liabilities and Stockholders' Equity
Dividends payable	25,726	265	$ 23,137
Subordinated debentures	134,051	126,135
Other liabilities	116,526	73,168
Total liabilities	10,599,630	8,507,292
Common stock	845	780
Paid-in capital	1,051,253	797,997
Retained earnings	473,183	402,259
Accumulated other comprehensive loss	(9,427)	(1,979)
Total stockholders’ equity	1,515,854	1,199,057	$ 1,116,869	$ 1,076,650
Total liabilities and stockholders’ equity	12,115,484	9,706,349
Parent Company
Assets
Cash on hand and in banks	22,000	9,304
Interest bearing cash deposits	42,299	38,420
Cash and cash equivalents	64,299	47,724
Other assets	12,639	8,871
Investment in subsidiaries	1,612,115	1,281,392
Total assets	1,689,053	1,337,987
Liabilities and Stockholders' Equity
Dividends payable	25,726	265
Subordinated debentures	134,051	126,135
Other liabilities	13,422	12,530
Total liabilities	173,199	138,930
Common stock	845	780
Paid-in capital	1,051,253	797,997
Retained earnings	473,183	402,259
Accumulated other comprehensive loss	(9,427)	(1,979)
Total stockholders’ equity	1,515,854	1,199,057
Total liabilities and stockholders’ equity	$ 1,689,053	$ 1,337,987

Condensed Statements of Operati

Condensed Statements of Operations and Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income
Gain on sale of investments									$ (1,113)	$ (660)	$ (1,463)
Expenses
Compensation and employee benefits									195,056	160,506	151,697
Other operating expenses									54,294	47,045	47,570
Total expenses	$ 81,876	$ 82,829	$ 81,795	$ 73,627	$ 68,366	$ 68,552	$ 65,309	$ 63,344	320,127	265,571	258,714
Income tax benefit	(11,647)	(10,802)	(9,485)	(8,397)	(31,327)	(11,639)	(11,905)	(9,754)	(40,331)	(64,625)	(39,662)
Net Income	$ 49,599	$ 49,336	$ 44,384	$ 38,559	$ 14,956	$ 36,479	$ 33,687	$ 31,255	181,878	116,377	121,131
Comprehensive Income									174,430	122,131	111,760
Parent Company
Income
Dividends from subsidiaries									153,574	119,000	108,350
Gain on sale of investments									0	3	0
Intercompany charges for services									16,523	14,299	12,248
Other income									1,284	225	311
Total income									171,381	133,527	120,909
Expenses
Compensation and employee benefits									20,873	17,864	15,665
Other operating expenses									12,201	10,425	7,701
Total expenses									33,074	28,289	23,366
Income before income tax benefit and equity in undistributed net income of subsidiaries									138,307	105,238	97,543
Income tax benefit									3,773	2,983	4,040
Income before equity in undistributed net income of subsidiaries									142,080	108,221	101,583
Equity in undistributed net income of subsidiaries									39,798	8,156	19,548
Net Income									181,878	116,377	121,131
Comprehensive Income									$ 174,430	$ 122,131	$ 111,760

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Activities
Net income	$ 49,599	$ 49,336	$ 44,384	$ 38,559	$ 14,956	$ 36,479	$ 33,687	$ 31,255	$ 181,878	$ 116,377	$ 121,131
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of purchase accounting adjustments									(3,963)	(5,131)	(2,252)
Gain on sale of investments									1,113	660	1,463
Stock-based compensation, net of tax benefits									3,122	2,952	1,844
Net cash provided by operating activities									280,711	254,741	193,087
Investing Activities
Sales of available-for-sale debt securities									226,842	247,748	62,817
Net (increase) decrease of premises and equipment									(18,637)	(10,128)	(8,306)
Net cash used in investing activities									(872,420)	23,655	(421,313)
Financing Activities
Net increase in other borrowed funds									(5,059)	3,784	(521)
Cash dividends paid									(85,493)	(111,720)	(84,040)
Tax withholding payments for stock-based compensation									(1,190)	(1,531)	(600)
Net cash used in financing activities									595,495	(230,933)	187,514
Net increase (decrease) in cash, cash equivalents and restricted cash									3,786	47,463	(40,712)
Cash, cash equivalents and restricted cash at beginning of period				200,004				152,541	200,004	152,541	193,253
Cash, cash equivalents and restricted cash at end of period	203,790				200,004				203,790	200,004	152,541
Parent Company
Operating Activities
Net income									181,878	116,377	121,131
Adjustments to reconcile net income to net cash provided by operating activities:
Subsidiary income in excess of dividends distributed									(39,798)	(8,156)	(19,548)
Amortization of purchase accounting adjustments									13	143	143
Gain on sale of investments									0	(3)	0
Stock-based compensation, net of tax benefits									1,219	1,460	804
Net change in other assets and other liabilities									(3,222)	5,051	(297)
Net cash provided by operating activities									140,090	114,872	102,233
Investing Activities
Sales of available-for-sale debt securities									0	27	0
Net (increase) decrease of premises and equipment									(300)	(79)	771
Proceeds from sale of non-marketable equity securities									0	114	55
Equity contribution to subsidiaries									(24,989)	(17,565)	(3,475)
Net cash used in investing activities									(25,289)	(17,503)	(2,649)
Financing Activities
Net increase in other borrowed funds									(11,543)	0	0
Cash dividends paid									(85,493)	(111,720)	(84,040)
Tax withholding payments for stock-based compensation									(1,190)	(1,531)	(600)
Net cash used in financing activities									(98,226)	(113,251)	(84,640)
Net increase (decrease) in cash, cash equivalents and restricted cash									16,575	(15,882)	14,944
Cash, cash equivalents and restricted cash at beginning of period				$ 47,724				$ 63,606	47,724	63,606	48,662
Cash, cash equivalents and restricted cash at end of period	$ 64,299				$ 47,724				$ 64,299	$ 47,724	$ 63,606

Unaudited Quarterly Financial_3

Unaudited Quarterly Financial Data (Condensed) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Summarized unaudited quarterly financial data
Interest income	$ 125,310	$ 122,905	$ 117,715	$ 103,066	$ 96,898	$ 96,464	$ 94,032	$ 87,628	$ 468,996	$ 375,022	$ 344,153
Interest expense	9,436	9,160	9,161	7,774	7,072	7,652	7,774	7,366	35,531	29,864	29,631
Net interest income	115,874	113,745	108,554	95,292	89,826	88,812	86,258	80,262	433,465	345,158	314,522
Provision for loan losses	1,246	3,194	4,718	795	2,886	3,327	3,013	1,598	9,953	10,824	2,333
Net interest income after provision for loan losses	114,628	110,551	103,836	94,497	86,940	85,485	83,245	78,664	423,512	334,334	312,189
Non-interest income	28,494	32,416	31,828	26,086	27,709	31,185	27,656	25,689	118,824	112,239	107,318
Non-interest expense	81,876	82,829	81,795	73,627	68,366	68,552	65,309	63,344	320,127	265,571	258,714
Income before income taxes	61,246	60,138	53,869	46,956	46,283	48,118	45,592	41,009	222,209	181,002	160,793
Federal and state income tax expense	11,647	10,802	9,485	8,397	31,327	11,639	11,905	9,754	40,331	64,625	39,662
Net Income	$ 49,599	$ 49,336	$ 44,384	$ 38,559	$ 14,956	$ 36,479	$ 33,687	$ 31,255	$ 181,878	$ 116,377	$ 121,131
Basic earnings per share	$ 0.59	$ 0.58	$ 0.53	$ 0.48	$ 0.19	$ 0.47	$ 0.43	$ 0.41	$ 2.18	$ 1.50	$ 1.59
Diluted earnings per share	$ 0.59	$ 0.58	$ 0.52	$ 0.48	$ 0.19	$ 0.47	$ 0.43	$ 0.41	$ 2.17	$ 1.50	$ 1.59

Fair Value Measurements on a Re

Fair Value Measurements on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financial Assets
Debt securities, available-for-sale	$ 2,571,663	$ 1,778,243
Recurring measurements
Financial Assets
Loans held for sale, at fair value	33,156	38,833
Total assets measured at fair value on a recurring basis	2,604,819	1,817,076
Financial Liabilities
Total liabilities measured at fair value on a recurring basis	3,769	9,389
Interest Rate Swaps | Recurring measurements
Financial Liabilities
Interest rate swaps	3,769	9,389
U.S. government and federal agency | Recurring measurements
Financial Assets
Debt securities, available-for-sale	23,649	31,127
U.S. government sponsored enterprises | Recurring measurements
Financial Assets
Debt securities, available-for-sale	120,208	19,091
State and local governments | Recurring measurements
Financial Assets
Debt securities, available-for-sale	852,250	629,501
Corporate bonds | Recurring measurements
Financial Assets
Debt securities, available-for-sale	290,817	216,762
Residential mortgage backed securities | Recurring measurements
Financial Assets
Debt securities, available-for-sale	792,915	779,283
Commercial mortgage backed securities | Recurring measurements
Financial Assets
Debt securities, available-for-sale	491,824	102,479
Level 1 | Recurring measurements
Financial Assets
Loans held for sale, at fair value	0	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 | Recurring measurements
Financial Liabilities
Interest rate swaps	0	0
Level 1 | U.S. government and federal agency | Recurring measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 1 | U.S. government sponsored enterprises | Recurring measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 1 | State and local governments | Recurring measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 1 | Corporate bonds | Recurring measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 1 | Residential mortgage backed securities | Recurring measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 1 | Commercial mortgage backed securities | Recurring measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 2 | Recurring measurements
Financial Assets
Loans held for sale, at fair value	33,156	38,833
Total assets measured at fair value on a recurring basis	2,604,819	1,817,076
Financial Liabilities
Total liabilities measured at fair value on a recurring basis	3,769	9,389
Level 2 | Interest Rate Swaps | Recurring measurements
Financial Liabilities
Interest rate swaps	3,769	9,389
Level 2 | U.S. government and federal agency | Recurring measurements
Financial Assets
Debt securities, available-for-sale	23,649	31,127
Level 2 | U.S. government sponsored enterprises | Recurring measurements
Financial Assets
Debt securities, available-for-sale	120,208	19,091
Level 2 | State and local governments | Recurring measurements
Financial Assets
Debt securities, available-for-sale	852,250	629,501
Level 2 | Corporate bonds | Recurring measurements
Financial Assets
Debt securities, available-for-sale	290,817	216,762
Level 2 | Residential mortgage backed securities | Recurring measurements
Financial Assets
Debt securities, available-for-sale	792,915	779,283
Level 2 | Commercial mortgage backed securities | Recurring measurements
Financial Assets
Debt securities, available-for-sale	491,824	102,479
Level 3 | Recurring measurements
Financial Assets
Loans held for sale, at fair value	0	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 | Recurring measurements
Financial Liabilities
Interest rate swaps	0	0
Level 3 | U.S. government and federal agency | Recurring measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 3 | U.S. government sponsored enterprises | Recurring measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 3 | State and local governments | Recurring measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 3 | Corporate bonds | Recurring measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 3 | Residential mortgage backed securities | Recurring measurements
Financial Assets
Debt securities, available-for-sale	0	0
Level 3 | Commercial mortgage backed securities | Recurring measurements
Financial Assets
Debt 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, 2018	Dec. 31, 2017
Assets with a recorded change from re-measuring at fair value on a non-recurring basis
Other real estate owned	$ 1,011	$ 2,296
Collateral-dependent impaired loans, net of ALLL	6,985	6,339
Total assets measured at fair value on a non-recurring basis	7,996	8,635
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	1,011	2,296
Collateral-dependent impaired loans, net of ALLL	6,985	6,339
Total assets measured at fair value on a non-recurring basis	$ 7,996	$ 8,635

Fair Value of Assets and Liab_3

Fair Value of Assets and Liabilities Quantitative Information about Level 3 Fair Value Measurements (Details) - Nonrecurring Measurements $ in Thousands		Dec. 31, 2018USD ($)Input	Dec. 31, 2017USD ($)Input
Quantitative Information About Level 3 Fair Value Measurements
Other real estate owned | $		$ 1,011	$ 2,296
Collateral-dependent impaired loans, net of ALLL | $		6,985	6,339
Level 3
Quantitative Information About Level 3 Fair Value Measurements
Other real estate owned | $		1,011	2,296
Collateral-dependent impaired loans, net of ALLL | $		6,985	6,339
Level 3 | Sales Comparison Approach | Selling costs
Quantitative Information About Level 3 Fair Value Measurements
Other real estate owned | $		1,011	2,296
Collateral-dependent impaired loans, net of ALLL | $		2,384	2,541
Level 3 | Combined Approach | Selling costs
Quantitative Information About Level 3 Fair Value Measurements
Collateral-dependent impaired loans, net of ALLL | $		$ 4,601	3,560
Level 3 | Cost Approach | Selling costs
Quantitative Information About Level 3 Fair Value Measurements
Collateral-dependent impaired loans, net of ALLL | $			$ 238
Level 3 | Minimum Range | Sales Comparison Approach | Selling costs
Quantitative Information About Level 3 Fair Value Measurements
Other real estate owned	[1]	0.080	0
Collateral-dependent impaired loans, net of ALLL	[1]	0.080	0.080
Level 3 | Minimum Range | Combined Approach | Selling costs
Quantitative Information About Level 3 Fair Value Measurements
Collateral-dependent impaired loans, net of ALLL	[1]	0.100	0.100
Level 3 | Minimum Range | Cost Approach | Selling costs
Quantitative Information About Level 3 Fair Value Measurements
Collateral-dependent impaired loans, net of ALLL	[1]		0.100
Level 3 | Maximum Range | Sales Comparison Approach | Selling costs
Quantitative Information About Level 3 Fair Value Measurements
Other real estate owned	[1]	0.150	0.100
Collateral-dependent impaired loans, net of ALLL	[1]	0.200	0.100
Level 3 | Maximum Range | Combined Approach | Selling costs
Quantitative Information About Level 3 Fair Value Measurements
Collateral-dependent impaired loans, net of ALLL	[1]	0.100	0.100
Level 3 | Maximum Range | Cost Approach | Selling costs
Quantitative Information About Level 3 Fair Value Measurements
Collateral-dependent impaired loans, net of ALLL	[1]		0.200
Level 3 | Weighted Average Range | Sales Comparison Approach | Selling costs
Quantitative Information About Level 3 Fair Value Measurements
Other real estate owned	[1]	0.092	0.060
Collateral-dependent impaired loans, net of ALLL	[1]	0.099	0.094
Level 3 | Weighted Average Range | Combined Approach | Selling costs
Quantitative Information About Level 3 Fair Value Measurements
Collateral-dependent impaired loans, net of ALLL	[1]	0.100	0.100
Level 3 | Weighted Average Range | Cost Approach | Selling costs
Quantitative Information About Level 3 Fair Value Measurements
Collateral-dependent impaired loans, net of ALLL	[1]		0.106
[1]	The range for selling cost inputs represents reductions to the fair value of the assets.

Carrying Amount and Fair Value

Carrying Amount and Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Carrying Amount
Financial Assets
Cash and cash equivalents	$ 203,790	$ 200,004
Debt securities, held-to-maturity	297,915	648,313
Loans receivable, net of ALLL	8,156,310	6,448,256
Total financial assets	8,658,015	7,296,573
Financial Liabilities
Term deposits	1,070,208	977,302
FHLB advances	440,175	353,995
Repurchase agreements and other borrowed funds	410,859	370,797
Subordinated debentures	134,051	126,135
Total financial liabilities	2,055,293	1,828,229
Estimated Fair Value | Level 1
Financial Assets
Cash and cash equivalents	203,790	200,004
Debt securities, held-to-maturity	0	0
Loans receivable, net of ALLL	0	0
Total financial assets	203,790	200,004
Financial Liabilities
Term deposits	0	0
FHLB advances	0	0
Repurchase agreements and other borrowed funds	0	0
Subordinated debentures	0	0
Total financial liabilities	0	0
Estimated Fair Value | Level 2
Financial Assets
Cash and cash equivalents	0	0
Debt securities, held-to-maturity	288,256	660,086
Loans receivable, net of ALLL	0	6,219,515
Total financial assets	288,256	6,879,601
Financial Liabilities
Term deposits	1,069,777	978,803
FHLB advances	439,615	352,886
Repurchase agreements and other borrowed funds	410,859	370,797
Subordinated debentures	120,302	98,023
Total financial liabilities	2,040,553	1,800,509
Estimated Fair Value | Level 3
Financial Assets
Cash and cash equivalents	0	0
Debt securities, held-to-maturity	0	0
Loans receivable, net of ALLL	8,079,112	114,771
Total financial assets	8,079,112	114,771
Financial Liabilities
Term deposits	0	0
FHLB advances	0	0
Repurchase agreements and other borrowed funds	0	0
Subordinated debentures	0	0
Total financial liabilities	$ 0	$ 0

Fair Value Measurements (Detail

Fair Value Measurements (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Fair value measurement transfers from one level to another	$ 0	$ 0	$ 0
Loans Held For Sale [Member] | Gain (Loss) on Sale of Loans [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	$ (155,000)	$ 994,000	$ 0

Contingencies and Commitments_2

Contingencies and Commitments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Outstanding Commitments
Outstanding commitments	$ 1,993,779	$ 1,605,194
Unused Lines of Credit
Outstanding Commitments
Outstanding commitments	1,948,516	1,565,112
Letters of Credit
Outstanding Commitments
Outstanding commitments	$ 45,263	$ 40,082

Consideration Transferred, Iden

Consideration Transferred, Identifiable Net Assets Acquired and Goodwill Recognized (Details) - USD ($)		Feb. 28, 2018	Jan. 31, 2018	Apr. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair value of consideration transferred
Effective settlement of pre-existing receivable					$ 10,054,000	$ 0	$ 0
Liabilities assumed
Goodwill recognized					$ 111,775,000	$ 30,758,000	$ 6,415,000
First Security Bank
Fair value of consideration transferred
Fair value of Company shares issued, net of equity issuance costs		$ 181,043,000
Cash consideration for outstanding shares		0
Effective settlement of pre-existing receivable		0
Total fair value of consideration transferred		181,043,000
Identifiable assets acquired
Cash and cash equivalents		24,397,000
Debt securities		271,865,000
Loans receivable		627,767,000
Core deposit intangible	[1]	31,053,000
Accrued income and other assets		78,274,000
Total identifiable assets acquired		1,033,356,000
Liabilities assumed
Deposits		877,586,000
Borrowings	[2]	36,880,000
Accrued expenses and other liabilities		14,175,000
Total liabilities assumed		928,641,000
Total identifiable net assets		104,715,000
Goodwill recognized		$ 76,328,000
Core Deposit Intangible, Weighted Average Useful Life		10 years
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed, Subordinated Debentures		$ 7,903,000
Collegiate Peaks Bank
Fair value of consideration transferred
Fair value of Company shares issued, net of equity issuance costs			$ 69,764,000
Cash consideration for outstanding shares			16,265,000
Effective settlement of pre-existing receivable			10,054,000
Total fair value of consideration transferred			96,083,000
Identifiable assets acquired
Cash and cash equivalents			93,136,000
Debt securities			42,177,000
Loans receivable			354,252,000
Core deposit intangible	[1]		10,275,000
Accrued income and other assets			15,911,000
Total identifiable assets acquired			515,751,000
Liabilities assumed
Deposits			437,171,000
Borrowings			12,509,000
Accrued expenses and other liabilities			5,435,000
Total liabilities assumed			455,115,000
Total identifiable net assets			60,636,000
Goodwill recognized			$ 35,447,000
Core Deposit Intangible, Weighted Average Useful Life			10 years
The Foothills Bank
Fair value of consideration transferred
Fair value of Company shares issued, net of equity issuance costs				$ 46,673,000
Cash consideration for outstanding shares				17,342,000
Effective settlement of pre-existing receivable				0
Total fair value of consideration transferred				64,015,000
Identifiable assets acquired
Cash and cash equivalents				13,251,000
Debt securities				25,420,000
Loans receivable				292,529,000
Core deposit intangible	[1]			4,331,000
Accrued income and other assets				19,699,000
Total identifiable assets acquired				355,230,000
Liabilities assumed
Deposits				296,760,000
Borrowings				22,800,000
Accrued expenses and other liabilities				2,264,000
Total liabilities assumed				321,824,000
Total identifiable net assets				33,406,000
Goodwill recognized				$ 30,609,000
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.
[2]	Borrowings assumed with the FSB acquisition include Tier 2 subordinated debentures of $7,903,000.

Pro Forma Summary (Details)

Pro Forma Summary (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
2018 acquisitions
Pro Forma Information
Net interest income and non-interest income	$ 560,979	$ 520,634
Net income	$ 177,267	138,042
2017 acquisitions
Pro Forma Information
Net interest income and non-interest income		462,603	$ 436,678
Net income		$ 114,187	$ 124,373

Mergers and Acquisitions (Detai

Mergers and Acquisitions (Details Textual) - USD ($)	Feb. 28, 2018	Jan. 31, 2018	Apr. 30, 2017	Dec. 31, 2018	Dec. 31, 2017
First Security Bank
Business Acquisition
Percentage of Outstanding Common Stock Acquired	100.00%
Fair value of consideration transferred	$ 181,043,000
Number of Shares Issued for Aquisition	4,654,091
Cash consideration for outstanding shares	$ 0
Loans receivable	627,767,000
Loans Receivable Acquired, Gross Principal and Contractual Interest Due	$ 632,370,000
Third-party Acquisition Related Costs				$ 4,714,000
Net interest income and non-interest income				42,796,000
Net income				11,303,000
Collegiate Peaks Bank
Business Acquisition
Percentage of Outstanding Common Stock Acquired		100.00%
Fair value of consideration transferred		$ 96,083,000
Number of Shares Issued for Aquisition		1,778,777
Cash consideration for outstanding shares		$ 16,265,000
Loans receivable		354,252,000
Loans Receivable Acquired, Gross Principal and Contractual Interest Due		$ 355,364,000
Third-party Acquisition Related Costs				1,683,000
Net interest income and non-interest income				23,921,000
Net income				$ 4,962,000
The Foothills Bank
Business Acquisition
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

Subsequent Event (Details Textu

Subsequent Event (Details Textual) - USD ($)	Jan. 16, 2019	Dec. 31, 2018	Dec. 31, 2017
Subsequent Event [Line Items]
Total assets		$ 12,115,484,000	$ 9,706,349,000
Gross loans		$ 8,287,549,000	$ 6,577,824,000
Acquisition of The First National Bank of Layton
Subsequent Event [Line Items]
Subsequent Event, Description	the Company announced the signing of a definitive agreement to acquire FNB Bancorp and its wholly-owned subsidiary, The First National Bank of Layton, a community bank based in Layton, Utah
Total assets	$ 334,709,000
Gross loans	246,724,000
Total deposits	$ 285,752,000