Nicolet Bankshares (NIC) 10-K 8 Mar 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Feb. 28, 2019	Jun. 30, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	NICOLET BANKSHARES INC
Entity Central Index Key	1,174,850
Trading Symbol	ncbs
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Well-known Seasoned Issuer	No
Entity Common Stock, Shares Outstanding		9,462,138
Entity Public Float			$ 440.9
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Amendment Flag	false
Entity Small Business	false
Entity Emerging Growth	false
Entity Shell Company	false
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Assets
Cash and due from banks		$ 85,896	$ 86,191
Interest-earning deposits		163,630	68,008
Federal funds sold		0	734
Cash and cash equivalents	[1]	249,526	154,933
Certificates of deposit in other banks		993	1,746
Securities available for sale (“AFS”), at fair value		400,144	405,153
Other investments		17,997	14,837
Loans held for sale		1,639	4,666
Loans		2,166,181	2,087,925
Allowance for loan losses		(13,153)	(12,653)
Loans, net		2,153,028	2,075,272
Premises and equipment, net		48,173	47,151
Bank owned life insurance (“BOLI”)		66,310	64,453
Goodwill and other intangibles, net		124,307	128,406
Accrued interest receivable and other assets		34,418	35,816
Total assets		3,096,535	2,932,433
Noninterest-bearing Deposit Liabilities		753,065	631,831
Liabilities:
Interest-bearing Deposit Liabilities		1,861,073	1,839,233
Total deposits		2,614,138	2,471,064
Short-term borrowings		0	0
Long-term borrowings		77,305	78,046
Accrued interest payable and other liabilities		17,740	18,444
Total liabilities		2,709,183	2,567,554
Stockholders’ Equity:
Common stock		95	98
Additional paid-in capital		247,790	263,835
Retained earnings		144,364	102,391
Accumulated other comprehensive loss		(5,640)	(2,146)
Total Nicolet Bankshares, Inc. stockholders’ equity		386,609	364,178
Noncontrolling interest		743	701
Total stockholders’ equity and noncontrolling interest		387,352	364,879
Total liabilities, noncontrolling interest and stockholders’ equity		$ 3,096,535	$ 2,932,433
Preferred shares authorized (no par value)		10,000,000	10,000,000
Preferred shares issued and outstanding		0	0
Common shares authorized (par value $0.01 per share)		30,000,000	30,000,000
Common shares outstanding		9,495,265	9,818,247
Common shares issued		9,524,777	9,849,167
[1]	Cash and cash equivalents include restricted cash of $6.3 million and $5.4 million at December 31, 2018 and 2017, respectively, for the reserve balance required with the Federal Reserve Bank. There was no reserve balance required at December 31, 2016.

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Preferred shares, no par value (in dollars per share)	$ 0	$ 0
Common shares, par value (in dollars per share)	$ 0.01	$ 0.01

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest income:
Loans, including loan fees	$ 113,953	$ 100,541	$ 69,425
Investment securities:
Taxable	6,068	4,728	3,029
Tax-exempt	2,296	2,360	1,686
Other interest income	3,220	1,624	1,327
Total interest income	125,537	109,253	75,467
Interest Expense, Deposits	15,420	7,686	5,144
Interest Expense, Short-term Borrowings	9	84	0
Interest Expense, Long-term Debt	3,460	2,741	2,190
Interest expense:
Total interest expense	18,889	10,511	7,334
Net interest income	106,648	98,742	68,133
Provision for loan losses	1,600	2,325	1,800
Net interest income after provision for loan losses	105,048	96,417	66,333
Noninterest income:
Mortgage income, net	6,344	5,361	5,494
BOLI income	2,418	1,778	1,284
Asset gains (losses), net	1,169	2,029	54
Noninterest Income, Other	5,528	4,454	4,045
Total noninterest income	39,509	34,639	26,674
Noninterest expense:
Personnel	49,476	44,458	34,030
Occupancy, equipment and office	14,574	13,308	10,276
Business development and marketing	5,324	4,700	3,488
Data processing	9,514	8,715	6,370
Intangibles amortization	4,389	4,695	3,458
Other expense	6,481	5,480	7,320
Total noninterest expense	89,758	81,356	64,942
Income before income tax expense	54,799	49,700	28,065
Income tax expense	13,446	16,267	9,371
Net income	41,353	33,433	18,694
Less: Net income attributable to noncontrolling interest	317	283	232
Net income attributable to Nicolet Bankshares, Inc.	41,036	33,150	18,462
Less: Preferred stock dividends	0	0	633
Net income available to common shareholders	$ 41,036	$ 33,150	$ 17,829
Earnings per common share:
Basic (in dollars per share)	$ 4.26	$ 3.51	$ 2.49
Diluted (in dollars per share)	$ 4.12	$ 3.33	$ 2.37
Weighted average common shares outstanding:
Basic (in shares)	9,640,258	9,439,951	7,158,367
Diluted (in shares)	9,956,353	9,958,160	7,513,971
Trust services fee income
Noninterest income:
Fees and commisions	$ 6,498	$ 6,031	$ 5,435
Brokerage fee income
Noninterest income:
Fees and commisions	7,042	5,736	3,624
Service charges on deposit accounts
Noninterest income:
Fees and commisions	4,845	4,604	3,571
Card interchange income
Noninterest income:
Fees and commisions	$ 5,665	$ 4,646	$ 3,167

Consolidated Statements of Comp

Consolidated 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	$ 41,353	$ 33,433	$ 18,694
Unrealized gains (losses) on securities AFS:
Net unrealized holding gains (losses) arising during the period	(3,715)	2,752	(5,999)
Reclassification adjustment for net (gains) losses included in net income	212	(1,220)	(78)
Income tax (expense) benefit	946	(598)	2,370
Total other comprehensive income (loss), net of tax	(2,557)	934	(3,707)
Comprehensive income	$ 38,796	$ 34,367	$ 14,987

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Preferred Equity	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Non- controlling Interest
Balance at Dec. 31, 2015	$ 109,687	$ 12,200	$ 42	$ 45,220	$ 51,059	$ 980	$ 186
Comprehensive income:
Net income	18,694				18,462		232
Other comprehensive loss	(3,707)					(3,707)
Stock-based compensation expense	1,608			1,608
Exercise of stock options, net, including income tax benefit	1,760			1,760
Issuance of common stock in acquisitions, net of capitalized issuance costs	165,035		44	164,991
Equity awards assumed in acquisition	1,182			1,182
Issuance of common stock	140		1	139
Purchase and retirement of common stock	(5,201)		(1)	(5,200)
Redemption of preferred stock	(12,200)	(12,200)
Preferred stock dividends	(633)				(633)
Balance at Dec. 31, 2016	276,365	$ 0	86	209,700	68,888	(2,727)	418
Comprehensive income:
Net income	33,433				33,150		283
Other comprehensive loss	934					934
Stock-based compensation expense	3,064			3,064
Exercise of stock options, net	3,801		2	3,799
Issuance of common stock in acquisitions, net of capitalized issuance costs	62,060		13	62,047
Issuance of common stock	229			229
Purchase and retirement of common stock	(15,007)		(3)	(15,004)
Reclassification of stranded tax effects in accumulated other comprehensive income					353	(353)
Balance at Dec. 31, 2017	364,879		98	263,835	102,391	(2,146)	701
Comprehensive income:
Net income	41,353				41,036		317
Other comprehensive loss	(2,557)					(2,557)
Stock-based compensation expense	4,901			4,901
Exercise of stock options, net	1,518		1	1,517
Issuance of common stock	282			282
Purchase and retirement of common stock	(22,749)		(4)	(22,745)
Reclassification of stranded tax effects in accumulated other comprehensive income					937
Distribution to noncontrolling interest	(275)						(275)
Balance at Dec. 31, 2018	$ 387,352		$ 95	$ 247,790	$ 144,364	(5,640)	$ 743
Comprehensive income:
Cumulative Effect on Retained Earnings, Net of Tax | Accounting Standards Update 2016-01						$ (937)

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Stockholders' Equity (Parentheticals) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Statement of Stockholders' Equity [Abstract]
Income tax benefit on exercise of stock options		$ 335
Capitalized issuance costs	$ 186	$ 260

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Cash Flows From Operating Activities:
Net income	$ 41,353		$ 33,433		$ 18,694
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion	6,282		7,067		5,132
Provision for loan losses	1,600		2,325		1,800
Provision for deferred taxes	(1,521)		6,962		2,966
Increase in cash surrender value of life insurance	1,857		1,778		1,284
Stock-based compensation expense	4,901		3,064		1,608
Assets (gains) losses, net	(1,169)		(2,029)		(54)
Gain on sale of loans held for sale, net	(5,499)		(4,777)		(5,248)
Proceeds from sale of loans held for sale	241,739		222,879		255,704
Origination of loans held for sale	(234,416)		(219,696)		(252,771)
Net change in accrued interest receivable and other assets	666		5,360		(301)
Net change in accrued interest payable and other liabilities	242		(1,377)		(2,042)
Net cash provided by operating activities	50,989		40,713		24,806
Cash Flows From Investing Activities:
Net decrease in certificates of deposit in other banks	753		2,238		1,432
Purchases of securities AFS	(76,564)		(63,117)		(82,448)
Proceeds from sales of securities AFS	5,280		10,798		31,442
Proceeds from calls and maturities of securities AFS	66,706		47,569		35,641
Net (increase) decrease in loans	(71,629)		(160,624)		2,805
Purchases of other investments	(1,550)		(3,320)		(3,447)
Proceeds from sales of other investments	807		6,678
Net increases in premises and equipment	4,260		2,018		4,048
Proceeds from sales of other real estate and other assets	2,824		1,724		1,999
Purchase of BOLI			0		(20,000)
Proceeds from redemption of BOLI	561		0		21,549
Net cash received in business combinations	0		9,119		66,517
Net cash provided by (used in) investing activities	(77,072)		(150,953)		51,442
Cash Flows From Financing Activities:
Net increase in deposits	143,153		126,782		91,236
Net decrease in short-term borrowings	0		0		(49,087)
Proceeds from long-term borrowings	0		30,000		0
Repayments of long-term borrowings	1,253		9,549		56,519
Distribution to noncontrolling interest	(275)		0		0
Capitalized issuance costs, net	0		(186)		(260)
Purchase and retirement of common stock	(22,749)		(15,007)		(5,201)
Proceeds from issuance of common stock, net	1,800		4,030		1,900
Redemption of preferred stock			0		(12,200)
Cash dividends paid on preferred stock			0		(633)
Net cash provided by (used in) financing activities	120,676		136,070		(30,764)
Net increase in cash and cash equivalents	94,593		25,830		45,484
Cash and cash equivalents:
Beginning cash and cash equivalents	154,933	[1]	129,103	[1]	83,619
Supplemental Disclosures of Cash Flow Information:
Cash paid for interest	18,537		10,932		7,508
Cash paid for taxes	10,821		12,789		7,150
Transfer of loans and bank premises to other real estate owned	607		828		237
Capitalized mortgage servicing rights	1,203		876		1,023
Transfer of loans from held for sale to held for investment	0		3,236		0
Acquisitions:
Fair value of assets acquired	0		439,000		1,039,000
Fair value of liabilities assumed	0		398,000		939,000
Net assets acquired	0		41,000		100,000
Common stock issued in acquisitions	$ 0		$ 62,246		$ 165,295
[1]	Cash and cash equivalents include restricted cash of $6.3 million and $5.4 million at December 31, 2018 and 2017, respectively, for the reserve balance required with the Federal Reserve Bank. There was no reserve balance required at December 31, 2016.

Consolidated Statements of Ca_2

Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Cash Flows [Abstract]
Restricted cash	$ 6.3	$ 5.4	$ 0

NATURE OF BUSINESS AND SIGNIFIC

NATURE OF BUSINESS AND SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
NATURE OF BUSINESS AND SIGNIFICANT ACCOUNTING POLICIES	NATURE OF BUSINESS AND SIGNIFICANT ACCOUNTING POLICIES Nature of Banking Activities and Subsidiaries : Nicolet Bankshares, Inc. (the “Company” or “Nicolet”) was incorporated on April 5, 2000, to serve as the holding company and sole shareholder of Nicolet National Bank (the “Bank”). The Bank opened for business on November 1, 2000. Since its opening in late 2000, Nicolet has supplemented its organic growth with branch purchase and acquisition transactions. See Note 2 for additional information on the Company’s recent acquisitions. The Company is part of a joint venture, Nicolet Joint Ventures, LLC (the “JV”), with a real estate development and investment firm (the “Firm”) established to develop and own the Company’s headquarters facility. The Firm is considered a related party, as one of its principals is a Board member and shareholder of the Company. The JV involves a 50% ownership by the Company. See Note 15 for additional related party disclosures. The Company also owns Brookfield Investment Partners, LLC (“Brookfield Investments”), an investment advisory firm that provides investment strategy and transactional services to financial institutions. During late 2016, the Company formed Nicolet Advisory Services, LLC (“Nicolet Advisory”), a wholly owned registered investment advisor subsidiary to provide brokerage and investment advisory services to customers. Through its acquisition of Baylake in 2016, the Bank owns a 49.8% indirect interest in United Financial Services, LLC, a data processing service and e-banking entity, through its 99.2% ownership of United Financial Services, Inc. (collectively referred to as “UFS”). The investment in UFS is carried in other assets under the equity method of accounting. The Bank’s pro rata share of UFS income is included in other noninterest income, and was $1.8 million and $1.3 million for the years ended December 31, 2018 and 2017 , respectively. Amounts paid to UFS for data processing services by the Bank were $2.8 million and $2.6 million in 2018 and 2017 , respectively. The carrying value of the Bank’s investment in UFS was $11.5 million and $9.7 million at December 31, 2018 and 2017 , respectively. Principles of Consolidation : The consolidated financial statements of the Company include the accounts of the Bank, Brookfield Investments, Nicolet Advisory and the JV. The JV underlies the noncontrolling interest reflected in the consolidated financial statements. The consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and conform to general practices within the banking industry. All significant intercompany accounts and transactions have been eliminated in the consolidated financial statements. Results of operations of companies purchased, if any, are included from the date of acquisition. Operating Segment: The consolidated income of the Company is derived principally from the Bank, which conducts lending (primarily commercial-based loans, as well as residential and consumer loans) and deposit gathering (including other banking- and deposit-related products and services, such as ATMs, safe deposit boxes, check-cashing, wires, and debit cards) to businesses, consumers and governmental units principally in its trade area of northeastern and central Wisconsin, and Menominee, Michigan, trust services, brokerage services (delivered through the Bank and Nicolet Advisory), and the support to deliver, fund and manage all such banking and wealth management services to its customer base. The contribution of the JV, Brookfield Investments and Nicolet Advisory were not significant to the consolidated balance sheet or net income for 2018 , 2017 , or 2016 . While the chief operating decision makers monitor the revenue streams of the various products and services, and evaluate costs, balance sheet positions and quality, all such products, services and activities are directly or indirectly related to the business of community banking, with no regular, formal or material segment delineations. Operations are managed and financial performance is evaluated on a company-wide basis, and accordingly, all the financial service operations are considered by management to be aggregated in one reportable operating segment. Use of Estimates : Preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying disclosures. These estimates are based on management’s best knowledge of current events and actions the Company may undertake in the future. Estimates are used in accounting for, among other items, the allowance for loan losses, valuation of loans in acquisition transactions, useful lives for depreciation and amortization, fair value of financial instruments, other-than-temporary impairment calculations, valuation of deferred tax assets, uncertain income tax positions, and contingencies. Estimates that are particularly susceptible to significant change for the Company include the determination of the allowance for loan losses, determination and assessment of deferred tax assets and liabilities, and the valuation of loans acquired in acquisition transactions; therefore, these are critical accounting policies. Factors that may cause sensitivity to the aforementioned estimates include but are not limited to: external market factors such as market interest rates and employment rates, changes to operating policies and procedures, changes in applicable banking or tax regulations, and changes to deferred tax estimates. Actual results may ultimately differ from estimates, although management does not generally believe such differences would materially affect the consolidated financial statements in any individual reporting period presented. Business Combinations: The Company accounts for business combinations under the acquisition method of accounting in accordance with Accounting Standards Codification (“ASC”) 805, Business Combinations (“ASC 805”). The Company recognizes the full fair value of the assets acquired and liabilities assumed and immediately expenses transaction costs. There is no separate recognition of the acquired allowance for loan losses on the acquirer’s balance sheet as credit related factors are incorporated directly into the fair value of the net tangible and intangible assets acquired. If the amount of consideration exceeds the fair value of assets purchased less the fair value of liabilities assumed, goodwill is recorded. Alternatively, if the amount by which the fair value of assets purchased exceeds the fair value of liabilities assumed and consideration paid, a gain (“bargain purchase gain”) is recorded. Fair values are subject to refinement for up to one year after the closing date of an acquisition as information relative to closing date fair values becomes available. Results of operations of the acquired business are included in the statements of income from the effective date of the acquisition. Additional information regarding recent acquisitions is provided in Note 2 . Cash and Cash Equivalents : For purposes of the consolidated statements of cash flows, cash and cash equivalents include cash and due from banks, interest-earning deposits in other banks with original maturities of less than 90 days, if any, and federal funds sold. The Bank maintains amounts in due from banks which, at times, may exceed federally insured limits. Management monitors these correspondent relationships. The Bank has not experienced any losses in such accounts. The Bank may have restrictions on cash and due from banks as it is required to maintain certain vault cash and reserve balances with the Federal Reserve Bank to meet specific reserve requirements. At December 31, 2018 and 2017 , the reserve balance required with the Federal Reserve Bank approximated $6.3 million and $5.4 million , respectively, of which there was sufficient cash to cover the reserve requirement. Securities Available for Sale : Securities classified as AFS are those securities that the Company intends to hold for an indefinite period of time, but not necessarily to maturity, and includes U.S. government agency securities; state, county and municipal securities; mortgage-backed securities; and corporate debt securities. Effective January 1, 2018, the Company adopted a new accounting standard, which requires equity securities with readily determinable fair values to be measured at fair value with changes in the fair value recognized through net income (see Recent Accounting Pronouncements Adopted within Note 1 for the impact of this new accounting guidance). Such securities are no longer reflected as securities AFS, and are now reflected within other investments on the consolidated balance sheets. Prior periods have not been restated for the impact of this accounting change. Thus, at December 31, 2018, the current fair value of $2.7 million for equity securities is included in other investments while at December 31, 2017, the fair value of $2.6 million for equity securities was reflected in securities AFS. Any decision to sell a security classified as AFS would be based on various factors, including significant movements in interest rates, changes in the maturity mix of the Company’s assets and liabilities, liquidity needs, regulatory capital considerations, and other similar factors. Securities classified as AFS are carried at fair value, with unrealized gains or losses, net of related deferred income taxes, reported as increases or decreases in accumulated other comprehensive income. Realized gains or losses on sales of securities AFS (using the specific identification method) and declines in value judged to be other-than-temporary are included in the consolidated statements of income under asset gains (losses), net. Premiums and discounts are amortized or accreted into interest income over the life of the related securities using the effective interest method. See Note 3 for additional disclosures on AFS securities. Management evaluates securities for other-than-temporary impairment on at least an annual basis. A decline in the market value of any investment below amortized cost that is deemed other-than-temporary is charged to earnings for the decline in value deemed to be credit related and a new cost basis in the security is established. The decline in value attributed to non-credit related factors considered temporary in nature is recognized in other comprehensive income. In evaluating other-than-temporary impairment, management considers the length of time and extent to which the fair value has been less than cost, and the financial condition and near-term prospects of the issuer for a period sufficient to allow for any anticipated recovery in fair value in the near term. Other Investments : Other investments includes equity securities with readily determinable fair values, "restricted" equity securities, and private company securities. As noted under Securities Available for Sale above, at December 31, 2018, other investments includes $2.7 million of equity securities with readily determinable fair values. As a member of the Federal Reserve Bank System, Federal Agricultural Mortgage Corporation, and the Federal Home Loan Bank (“FHLB”) System, the Bank is required to maintain an investment in the capital stock of these entities. These equity securities are “restricted” in that they can only be sold back to the respective institutions or another member institution at par. Therefore, they are less liquid than other exchange traded equity securities. As no ready market exists for these stocks, and they have no quoted market value, these investments are carried at cost. Also included are investments in other private companies that do not have quoted market prices, which are carried at cost less other-than-temporary impairment charges, if any. Management’s evaluation of these other investments for impairment includes consideration of the financial condition and other available relevant information of the issuer. Loans Held for Sale : Loans originated and intended for sale in the secondary market are carried at the lower of cost or estimated fair value as determined on an aggregate basis and generally consist of current production of certain fixed-rate residential first mortgages. The amount by which cost exceeds market value is recorded as a valuation allowance and charged to earnings. Changes, if any, in the valuation allowance are also included in earnings in the period in which the change occurs. As of December 31, 2018 and 2017 , no valuation allowance was necessary. Loans held for sale may be sold servicing retained or servicing released, and are generally sold without recourse. The carrying value of mortgage loans sold with servicing retained is reduced by the amount allocated to the servicing right at the time of sale. Gains and losses on sales of mortgage loans held for sale are included in earnings in mortgage income, net. Loans and Allowance for Loan Losses (“ALLL”) – Originated Loans : Loans that management has the intent and ability to hold for the foreseeable future or until maturity or payoff are carried at their principal amount outstanding, net of deferred loan fees and costs. Interest income is accrued on the unpaid principal balance using the simple interest method. The accrual of interest income on loans is discontinued when, in the opinion of management, there is reasonable doubt as to the borrower’s ability to meet payment of interest or principal when due. Loans are generally placed on nonaccrual status when contractually past due 90 days or more as to interest or principal, though may be placed in such status earlier based on the circumstances. Loans past due 90 days or more may continue on accrual only when they are well secured and/or in process of collection or renewal. When interest accrual is discontinued, all previously accrued but uncollected interest is reversed against current period interest income. Except in very limited circumstances, cash collections on nonaccrual loans are credited to the loan receivable balance and no interest income is recognized on those loans until the principal balance is paid in full. Accrual of interest may be resumed when the customer is current on all principal and interest payments and has been paying on a timely basis for a sustained period of time. See Note 4 for additional information and disclosures on originated loans. Management considers a loan to be impaired when it is probable the Company will be unable to collect all contractual principal and interest payments due in accordance with the terms of the loan agreement. For determining the appropriateness of the ALLL, management defines impaired loans as nonaccrual credit relationships over $250,000 , all loans determined to be troubled debt restructurings, plus additional loans with impairment risk characteristics. At the time an individual loan goes into nonaccrual status, management evaluates the loan for impairment and possible charge-off regardless of loan size. Typically, impairment amounts for loans under the scope criteria are charged off when the impairment amount is determined. The ALLL represents management’s estimate of probable and inherent credit losses in the Company’s loan portfolio at the balance sheet date. In general, estimating the amount of the ALLL is a function of a number of factors, including but not limited to changes in the loan portfolio, net charge-offs, trends in past due and impaired loans, and the level of potential problem loans, all of which may be susceptible to significant change. Actual credit losses, net of recoveries, are deducted from the ALLL. Loans are charged off when management believes that the collectability of the principal is unlikely. Subsequent recoveries, if any, are credited to the ALLL. A provision for loan losses, which is a charge against income, is recorded to bring the ALLL to a level that, in management’s judgment, is appropriate to absorb probable losses in the loan portfolio. The allocation methodology applied by the Company is designed to assess the overall appropriateness of the ALLL and includes allocations for specifically identified impaired loans and loss factors for all remaining loans, with a component primarily based on historical loss rates and another component primarily based on other qualitative factors. Impaired loans are individually assessed and are measured based on the present value of expected future cash flows discounted at the loan’s effective interest rate or, as a practical expedient, at the loan’s observable market price or the fair value of the collateral if the loan is collateral dependent. Loans that are determined not to be impaired are collectively evaluated for impairment, stratified by type and allocated loss ranges based on the Company’s actual historical loss ratios for each strata, and adjustments are also provided for certain current environmental and qualitative factors. An internal loan review function rates loans using a grading system based on nine different categories. Loans with grades of seven or higher (“classified loans”) represent loans with a greater risk of loss and may be assigned allocations for loss based on specific review of the weaknesses observed in the individual credits if classified as impaired. Classified loans are constantly monitored by the loan review function to ensure early identification of any deterioration. Allocations to the ALLL may be made for specific loans but the entire ALLL is available for any loan that, in management’s judgment, should be charged-off or for which an actual loss is realized. The allowance analysis is reviewed by the Board on a quarterly basis in compliance with internal and regulatory requirements. Loans and ALLL – Acquired Loans: The loans purchased in acquisition transactions are acquired loans. Acquired loans are recorded at their estimated fair value at the acquisition date, and are initially classified as either purchase credit impaired (“PCI”) loans (i.e., loans that reflect credit deterioration since origination and it is probable at acquisition that the Company will be unable to collect all contractually required payments) or purchased non-impaired loans (i.e., “performing acquired loans”). See Note 4 for additional information and disclosures on acquired loans. PCI loans are accounted for under the accounting guidance for loans and debt securities acquired with deteriorated credit quality, found in Financial Accounting Standards Board (“FASB”) ASC Topic 310-30, Receivables—Loans and Debt Securities Acquired with Deteriorated Credit Quality . The Company estimates the amount and timing of expected principal, interest and other cash flows for each loan or pool of loans meeting the criteria above, and determines the excess of the loan’s scheduled contractual principal and contractual interest payments over all cash flows expected to be collected at acquisition as an amount that should not be accreted. These credit discounts (“nonaccretable marks”) are included in the determination of the initial fair value for acquired loans; therefore, an allowance for loan losses is not recorded at the acquisition date. Differences between the estimated fair values and expected cash flows of acquired loans at the acquisition date that are not credit-based (“accretable marks”) are subsequently accreted to interest income over the estimated life of the loans using a method that approximates a level yield if the timing and amount of the future cash flows is reasonably estimable. Subsequent to the acquisition date for PCI loans, increases in cash flows over those expected at the acquisition date result in a move of the discount from nonaccretable to accretable. Decreases in expected cash flows after the acquisition date are recognized through the provision for loan losses. All fair value discounts initially recorded on PCI loans were deemed to be credit related. Performing acquired loans are accounted for under FASB ASC Topic 310-20, Receivables—Nonrefundable Fees and Other Costs . Performance of certain loans may be monitored, and based on management’s assessment of the cash flows and other facts available, portions of the accretable difference may be delayed or suspended if management deems appropriate. The Company’s policy for determining when to discontinue accruing interest on performing acquired loans and the subsequent accounting for such loans is essentially the same as the policy for originated loans described above. An ALLL is calculated using a methodology similar to that described for originated loans. Performing acquired loans are subsequently evaluated for any required allowance at each reporting date. Such required allowance for each loan pool is compared to the remaining fair value discount for that pool. If greater, the excess is recognized as an addition to the allowance through a provision for loan losses charge. If less than the discount, no additional allowance is recorded. Charge-offs and losses first reduce any remaining fair value discount for the loan pool and once the discount is depleted, losses are applied against the allowance established for that pool. For PCI loans after acquisition, cash flows expected to be collected are recast for each loan periodically as determined appropriate by management. If the present value of expected cash flows for a loan is less than its carrying value, impairment is reflected by an increase in the ALLL and a charge to the provision for loan losses. If the present value of the expected cash flows for a loan is greater than its carrying value, any previously established ALLL is reversed and any remaining difference increases the accretable yield which will be taken into income over the remaining life of the loan. Loans which were considered troubled debt restructurings prior to the acquisition transaction are not required to be classified as troubled debt restructurings in the Company’s consolidated financial statements unless or until such loans would subsequently meet criteria to be classified as such, since acquired loans were recorded at their estimated fair values at the time of the acquisition. Credit-Related Financial Instruments : In the ordinary course of business the Company has entered into financial instruments consisting of commitments to extend credit, financial standby letters of credit, and performance standby letters of credit. Financial standby letters of credit are issued specifically to facilitate commerce and typically result in the commitment being drawn on when the underlying transaction is consummated between the customer and the third party, while performance standby letters of credit generally are contingent upon the failure of the customer to perform according to the terms of the underlying contract with the third party. Such financial instruments are recorded in the consolidated financial statements when they are funded. See Note 14 for additional information and disclosures on credit-related financial instruments. Transfers of Financial Assets : Transfers of financial assets, primarily in loan participation activities, are accounted for as sales only when control over the assets has been surrendered. Control over transferred assets is deemed to be surrendered when (1) the assets have been isolated from the Company, (2) the transferee obtains the right (free of conditions that constrain it from taking advantage of the right) to pledge or exchange the transferred assets, and (3) the Company does not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity or the ability to unilaterally cause the holder to return assets. Premises and Equipment : Premises and equipment are stated at cost less accumulated depreciation and amortization. Premises and equipment from acquisitions were recorded at estimated fair value on the respective dates of acquisition. Depreciation is computed on straight-line and accelerated methods over the estimated useful lives of the related assets. Leasehold improvements are amortized on the straight-line method over the shorter of the estimated useful lives of the improvements or the terms of the related leases. Maintenance and repairs are expensed as incurred. See Note 5 for additional information on premises and equipment. Estimated useful lives of new premises and equipment generally range as follows: Building and improvements 25 – 40 years Leasehold improvements 5 – 15 years Furniture and equipment 3 – 10 years Other Real Estate Owned (“OREO”) : OREO acquired through partial or total satisfaction of loans or bank facilities no longer in use are carried at fair value less estimated costs to sell. Any write-down in the carrying value of loans or vacated bank premises at the time of transfer to OREO is charged to the ALLL or to write-down of assets, respectively. OREO properties acquired in conjunction with the acquisition transactions were recorded at fair value on the date of acquisition. Any subsequent write-downs to reflect current fair value, as well as gains or losses on disposition and revenues and expenses incurred to hold and maintain such properties, are treated as period costs. See Note 7 for additional information on OREO. Goodwill and Other Intangibles : Goodwill represents the excess of the purchase price over the fair value of the net identifiable assets acquired. Goodwill is not amortized but is subject to impairment tests on at least an annual basis. Other intangibles include core deposit intangibles (which represent the value of acquired customer core deposit bases) and customer list intangibles. The core deposit intangibles have an estimated finite life, are amortized on an accelerated basis over a 10 -year period, and are subject to periodic impairment evaluation. The customer list intangibles have finite lives and are amortized on a straight-line basis to expense over their initial weighted average life of approximately 12 years as of acquisition. See Note 6 for additional information on goodwill and other intangibles. Management periodically reviews the carrying value of its intangible assets to determine if any impairment has occurred, in which case an impairment charge would be recorded as an expense in the period of impairment, or whether changes in circumstances have occurred that would require a revision to the remaining useful life which would impact expense prospectively. In making such determination, management evaluates whether there are any adverse qualitative factors indicating that an impairment may exist, as well as the performance, on an undiscounted basis, of the underlying operations or assets which give rise to the intangible. The Company’s annual assessments indicated no impairment charge on goodwill or other intangibles was required for 2018 or 2017 . Mortgage Servicing Rights (“MSRs”): If the Company sells originated residential mortgages into the secondary market and retains the right to service the loans sold, then a mortgage servicing right asset (liability) is capitalized upon sale with the offsetting effect recorded as a gain (loss) on sale of loans in earnings (included in mortgage income, net), representing the then-current estimated fair value of future net cash flows expected to be realized for performing the servicing activities. MSRs when purchased (including MSRs purchased in acquisitions) are initially recorded at their then-estimated fair value. As the Company has not elected to measure any class of servicing assets under the fair value method, the Company utilizes the amortization method. MSRs are amortized in proportion to and over the period of estimated net servicing income, with the amortization charged to earnings (included in mortgage income, net). MSRs are carried at the lower of initial capitalized amount, net of accumulated amortization, or estimated fair value, and are included in other assets in the consolidated balance sheets. Loan servicing fee income for servicing loans is typically based on a contractual percentage of the outstanding principal and is recorded as income when earned (included in mortgage income, net with less material late fees and ancillary fees related to loan servicing). The Company periodically evaluates its MSRs for impairment. At each reporting date impairment is assessed based on estimated fair value using estimated prepayment speeds of the underlying mortgage loans serviced and stratifications based on the risk characteristics of the underlying loans (predominantly loan type and note interest rate). The value of MSRs is adversely affected when mortgage interest rates decline and mortgage loan prepayments increase. A valuation allowance is established through a charge to earnings (included in mortgage income, net) to the extent the amortized cost of the MSRs exceeds the estimated fair value by stratification. If it is later determined that all or a portion of the temporary impairment no longer exists for a stratification, the valuation is reduced through a recovery to earnings, though not beyond the net amortized cost carried. An other-than-temporary impairment (i.e., recoverability is considered remote when considering interest rates and loan payoff activity) is recognized as a write-down of the MSRs and the related valuation allowance (to the extent a valuation allowance is available) and then against earnings. A direct write-down permanently reduces the carrying value of the MSRs and valuation allowance, precluding subsequent recoveries. No valuation allowance or impairment charge was recorded for 2018 or 2017 . See Note 6 for additional information on MSRs. Bank-owned Life Insurance (“BOLI”): The Company owns BOLI on certain executives and employees. BOLI balances are recorded at their cash surrender values. Changes in the cash surrender values and death proceeds exceeding carrying values are included in noninterest income. Short-term Borrowings : Short-term borrowings consist primarily of overnight Federal funds purchased and securities sold under agreements to repurchase (“repos”), or other short-term borrowing arrangements with an original maturity of one year or less. Repos are with commercial deposit customers, and are treated as financing activities carried at the amounts that will be subsequently repurchased as specified in the respective agreements. Repos generally mature within one to four days from the transaction date. The Company may be required to provide additional collateral based on the fair value of the underlying securities. There were no outstanding agreements at December 31, 2018 or 2017 and there were no repurchase agreements transacted during 2018 or 2017 . Stock-based Compensation Plans: Share-based payments to employees, including grants of restricted stock or stock options, are valued at fair value of the award on the date of grant and expensed on a straight-line basis as compensation expense over the applicable vesting period. A Black-Scholes model is utilized to estimate the fair value of stock options and the market price of the Company’s stock at the date of grant is used to estimate the fair value of restricted stock awards. See Note 11 for additional information on stock-based compensation. Income Taxes : The Company files a consolidated federal income tax return and a combined state income tax return (both of which include the Company and its wholly owned subsidiaries). Accordingly, amounts equal to tax benefits of those companies having taxable federal losses or credits are reimbursed by the companies that incur federal tax liabilities. Amounts provided for income tax expense are based on income reported for financial statement purposes and do not necessarily represent amounts currently payable under tax laws. Deferred income tax assets and liabilities are computed annually for differences between the financial statement and tax bases of assets and liabilities that will result in taxable or deductible amounts in the future based on enacted tax rates applicable to the periods in which the differences are expected to affect taxable income. As changes in tax laws or rates are enacted, deferred tax assets and liabilities are adjusted through income tax expense. Valuation allowances are established when it is more likely than not that a portion of the full amount of the deferred tax asset will not be realized. In assessing the ability to realize deferred tax assets, management considers the scheduled reversal of deferred tax liabilities,

ACQUISITIONS

ACQUISITIONS	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
ACQUISITIONS	ACQUISITIONS Brokerage business acquired: During the third quarter of 2018, Nicolet purchased a small brokerage book of business from a retiring financial advisor in support of the Company's initiative to expand its wealth management business. As a result of this purchase, the Company recorded a customer list intangible of $290,000 which will be amortized on a straight-line basis. First Menasha: On April 28, 2017, the Company consummated its merger with First Menasha Bancshares, Inc. (“First Menasha”) pursuant to the Agreement and Plan of Merger by and between the Company and First Menasha dated November 3, 2016, (the “Merger Agreement”), whereby First Menasha was merged with and into the Company, and The First National Bank-Fox Valley, the wholly owned commercial bank subsidiary of First Menasha serving the Fox Valley area of Wisconsin, was merged with and into the Bank. The system integration was completed, and five branches of First Menasha opened on May 1, 2017, as Nicolet National Bank branches, expanding its presence in Calumet and Winnebago Counties, Wisconsin. The Company closed one of its Calumet County locations concurrently with the First Menasha merger. The purpose of the merger was to continue Nicolet’s interest in strategic growth, consistent with its plan to improve profitability through efficiency, leverage the strengths of each bank across the combined customer base, and add shareholder value. With the merger, Nicolet became the leading community bank to serve the Fox Valley area of Wisconsin. Pursuant to the Merger Agreement, the final purchase price consisted of issuing 1,309,885 shares of the Company’s common stock (given the final stock-for-stock exchange ratio of 3.126 except for First Menasha shares owned by the Company immediately prior to the time of the merger), for common stock consideration of $62.2 million (based on $47.52 per share, the volume weighted average closing price of the Company’s common stock over the preceding 20 trading day period) plus cash consideration of $19.3 million . Approximately $0.2 million in direct stock issuance costs for the merger were incurred and charged against additional paid-in capital. Upon consummation, the Company added $480 million in assets, $351 million in loans, $375 million in deposits, $4 million in core deposit intangible, and $41 million of goodwill. The Company accounted for the transaction under the acquisition method of accounting, and thus, the financial position and results of operations of First Menasha prior to the consummation date were not included in the accompanying consolidated financial statements. The accounting required assets purchased and liabilities assumed to be recorded at their respective estimated fair values at the date of acquisition. During third quarter 2017, adjustments were made to the initial fair value estimates based on additional information and goodwill increased $1 million (to $41 million ) to account for the gain in the Company’s pre-acquisition equity interest holding in First Menasha, resulting in a $1.2 million gain in pre-tax earnings. Financial advisor business acquired: During the first quarter of 2016, Nicolet agreed in a private transaction to hire a select group of financial advisors and purchase their respective books of business, as well as their operating platform, to enhance the leadership and future growth of the Company’s wealth management business. The transaction was effected in phases and completed April 1, 2016. The Company paid $4.9 million total initial consideration, including $0.8 million cash, $2.6 million of Nicolet common stock, and recorded a $1.5 million earn-out liability payable to one principal in the future. The Company initially recorded $0.4 million of goodwill, $0.2 million of fixed assets, and $4.3 million of customer relationship intangibles (a portion amortizing straight-line over 10 years and a portion over 15 years). During 2017, the previously variable earn-out liability was agreed to be modified to a fixed amount. Therefore, the earn-out liability was adjusted to $2.4 million , with a corresponding $0.9 million increase in the customer relationship intangible, being amortized over the original term. The transaction impacts the income statement primarily within brokerage fee income, personnel expense, and intangibles amortization. Baylake: On April 29, 2016, the Company consummated its merger with Baylake. The system integration was completed, and 21 branches of Baylake opened, on May 2, 2016, as branches of the Bank, expanding its presence into Door, Kewaunee, and Manitowoc Counties, Wisconsin. The Company closed one of its Brown County locations concurrently with the Baylake merger, and closed an additional six branches in the fourth quarter of 2016. The purpose of the merger was for strategic reasons beneficial to the Company. The acquisition was consistent with its plan to drive growth and efficiency through increased scale, leverage the strengths of each bank across the combined customer base, enhance profitability, and add liquidity and shareholder value. Baylake shareholders received 0.4517 shares of the Company’s common stock for each outstanding share of Baylake common stock (except for Baylake shares owned by the Company at the time of the merger), and cash in lieu of any fractional share. Pre-existing Baylake equity awards (restricted stock units and stock options) immediately vested upon consummation of the merger. The Company issued 0.4517 shares of its common stock for each vesting Baylake restricted stock unit, and Nicolet assumed, after appropriate adjustment by the 0.4517 exchange ratio, all pre-existing Baylake stock options. As a result, the Company issued 4,344,243 shares of the Company’s common stock, for common stock consideration of $163.3 million (based on $37.58 per share, the volume weighted average closing price of the Company’s common stock over the preceding 20 trading day period) and recorded an additional $1.2 million consideration for the assumed stock options. Approximately $0.3 million in direct stock issuance costs for the merger were incurred and charged against additional paid-in capital. The Company accounted for the transaction under the acquisition method of accounting, and thus, the financial position and results of operations of Baylake prior to the consummation date were not included in the accompanying consolidated financial statements. The fair value of the assets acquired and liabilities assumed on April 29, 2016 was as follows. (in millions) As recorded by Fair Value As Recorded Cash, cash equivalents and securities available for sale $ 262 $ 1 $ 263 Loans 710 (19 ) 691 Other real estate owned 3 (2 ) 1 Core deposit intangible 1 16 17 Fixed assets and other assets 71 (8 ) 63 Total assets acquired $ 1,047 $ (12 ) $ 1,035 Deposits $ 822 $ — $ 822 Junior subordinated debentures, borrowings and other liabilities 116 (1 ) 115 Total liabilities acquired $ 938 $ (1 ) $ 937 Excess of assets acquired over liabilities acquired $ 109 $ (11 ) $ 98 Less: purchase price 164 Goodwill $ 66 The following unaudited pro forma information presents the results of operations for the year ended December 31, 2016, as if the acquisition had occurred January 1 of each period. These unaudited pro forma results are presented for illustrative purposes and are not intended to represent or be indicative of the actual results of operations of the combined company that would have been achieved had the acquisition occurred at the beginning of each period presented, nor are they intended to represent or be indicative of future results of operations. Year Ended December 31, 2016 (in thousands, except per share data) Total revenues, net of interest expense $ 110,788 Net income 23,263 Diluted earnings per share 2.55

SECURITIES AVAILABLE FOR SALE

SECURITIES AVAILABLE FOR SALE	12 Months Ended
	Dec. 31, 2018
Debt Securities, Available-for-sale [Abstract]
SECURITIES AVAILABLE FOR SALE	SECURITIES AVAILABLE FOR SALE Amortized cost and fair value of securities available for sale are summarized as follows. December 31, 2018 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. government agency securities $ 22,467 $ — $ 818 $ 21,649 State, county and municipals 163,702 76 3,252 160,526 Mortgage-backed securities 134,350 328 3,034 131,644 Corporate debt securities 87,352 66 1,093 86,325 $ 407,871 $ 470 $ 8,197 $ 400,144 December 31, 2017 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. government agency securities $ 26,586 $ — $ 377 $ 26,209 State, county and municipals 186,128 180 2,264 184,044 Mortgage-backed securities 157,705 160 2,333 155,532 Corporate debt securities 36,387 449 39 36,797 Equity securities * 1,287 1,284 — 2,571 $ 408,093 $ 2,073 $ 5,013 $ 405,153 * Effective January 1, 2018, the Company adopted ASU 2016-01, which requires equity securities with readily determinable fair values to be measured at fair value with changes in the fair value recognized through net income. These equity securities are no longer reflected in securities AFS and are now reflected within other investments. As a result of this accounting change, the Company recognized a cumulative-effect adjustment at adoption from accumulated other comprehensive income to retained earnings of approximately $0.9 million in the consolidated statements of changes in stockholders' equity for the net of tax impact of the unrealized gain on equity securities as of the date of adoption and recognized a gain of approximately $77,000 for the year ended December 31, 2018 , in the consolidated statements of income for the change in fair value of equity securities since adoption. In addition, the approximately $2.7 million current fair value of equity securities is now reflected within other investments on the consolidated balance sheets rather than as securities AFS. Prior periods have not been restated for the impact of this accounting change. See Note 1 for additional information on this new accounting standard. The following table presents gross unrealized losses and the related estimated fair value of investment securities available for sale, aggregated by investment category and the length of time the individual securities have been in a continuous unrealized loss position. December 31, 2018 Less than 12 months 12 months or more Total (in thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Number of Securities U.S. government agency securities $ — $ — $ 21,649 $ 818 $ 21,649 $ 818 3 State, county and municipals 16,136 98 130,975 3,154 147,111 3,252 440 Mortgage-backed securities 20,568 132 89,189 2,902 109,757 3,034 204 Corporate debt securities 51,592 677 9,757 416 61,349 1,093 33 $ 88,296 $ 907 $ 251,570 $ 7,290 $ 339,866 $ 8,197 680 December 31, 2017 Less than 12 months 12 months or more Total (in thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Number of Securities U.S. government agency securities $ 26,209 $ 377 $ — $ — $ 26,209 $ 377 2 State, county and municipals 110,157 1,097 49,326 1,167 159,483 2,264 465 Mortgage-backed securities 72,210 735 65,537 1,598 137,747 2,333 215 Corporate debt securities 10,172 39 — — 10,172 39 5 $ 218,748 $ 2,248 $ 114,863 $ 2,765 $ 333,611 $ 5,013 687 As of December 31, 2018 , the Company does not consider its securities AFS with unrealized losses to be other-than-temporarily impaired as the unrealized losses in each category have occurred as a result of changes in interest rates, market spreads, and market conditions subsequent to purchase, not credit deterioration. The Company has the ability and intent to hold its securities to maturity. There were no other-than-temporary impairment charges recognized in earnings on securities AFS during 2018 , 2017 , or 2016 . The Company incurred a $0.5 million other-than-temporary impairment charge to earnings related to one private company stock carried in other investments in the consolidated balance sheets during 2016 compared to none in 2017 and 2018. The amortized cost and fair value of securities AFS by contractual maturity are shown below. Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties; as this is particularly inherent in mortgage-backed securities, these securities are not included in the maturity categories below. See Note 18 for additional information on the Company’s fair value measurements. December 31, 2018 (in thousands) Amortized Cost Fair Value Due in less than one year $ 17,643 $ 17,624 Due in one year through five years 168,090 164,969 Due after five years through ten years 80,819 78,904 Due after ten years 6,969 7,003 273,521 268,500 Mortgage-backed securities 134,350 131,644 Securities AFS $ 407,871 $ 400,144 AFS securities with a carrying value of $157.2 million and $140.9 million as of December 31, 2018 and 2017 , respectively, were pledged as collateral on public deposits and for other purposes as required or permitted by law. Proceeds from sales of securities AFS is summarized as follows. Years Ended December 31, (in thousands) 2018 2017 2016 Gross gains $ — $ 1,227 $ 91 Gross losses (212 ) (7 ) (13 ) Gains (losses) on sales of securities AFS, net $ (212 ) $ 1,220 $ 78 Proceeds from sales of securities AFS $ 5,280 $ 10,798 $ 31,442

LOANS, ALLOWANCE FOR LOAN LOSSE

LOANS, ALLOWANCE FOR LOAN LOSSES, AND CREDIT QUALITY	12 Months Ended
	Dec. 31, 2018
Receivables [Abstract]
LOANS, ALLOWANCE FOR LOAN LOSSES, AND CREDIT QUALITY	LOANS, ALLOWANCE FOR LOAN LOSSES, AND CREDIT QUALITY The loan composition is summarized as follows. December 31, 2018 December 31, 2017 (in thousands) Amount % of Total Amount % of Total Commercial & industrial $ 684,920 32 % $ 637,337 31 % Owner-occupied commercial real estate (“CRE”) 441,353 20 430,043 21 Agricultural (“AG”) production 35,625 2 35,455 2 AG real estate 53,444 2 51,778 2 CRE investment 343,652 16 314,463 15 Construction & land development 80,599 4 89,660 4 Residential construction 30,926 1 36,995 2 Residential first mortgage 357,841 17 363,352 17 Residential junior mortgage 111,328 5 106,027 5 Retail & other 26,493 1 22,815 1 Loans 2,166,181 100 % 2,087,925 100 % Less ALLL 13,153 12,653 Loans, net $ 2,153,028 $ 2,075,272 ALLL to loans 0.61 % 0.61 % As a further breakdown, loans are summarized by originated and acquired as follows. December 31, 2018 December 31, 2017 (in thousands) Originated Amount % of Total Acquired Amount % of Total Originated Amount % of Total Acquired Amount % of Total Commercial & industrial $ 568,100 38 % $ 116,820 17 % $ 488,600 39 % $ 148,737 17 % Owner-occupied CRE 283,531 19 157,822 23 237,548 19 192,495 23 AG production 11,113 1 24,512 4 11,102 1 24,353 3 AG real estate 31,374 2 22,070 3 27,831 2 23,947 3 CRE investment 171,087 12 172,565 25 113,862 9 200,601 24 Construction & land development 66,478 4 14,121 2 56,061 5 33,599 4 Residential construction 30,926 2 — — 33,615 3 3,380 — Residential first mortgage 220,368 15 137,473 20 191,186 15 172,166 20 Residential junior mortgage 78,379 5 32,949 5 65,643 5 40,384 5 Retail & other 23,809 2 2,684 1 18,254 2 4,561 1 Loans 1,485,165 100 % 681,016 100 % 1,243,702 100 % 844,223 100 % Less ALLL 11,448 1,705 10,542 2,111 Loans, net $ 1,473,717 $ 679,311 $ 1,233,160 $ 842,112 ALLL to loans 0.77 % 0.25 % 0.85 % 0.25 % Practically all of the Company’s loans, commitments, and letters of credit have been granted to customers in the Company’s market area. Although the Company has a diversified loan portfolio, the credit risk in the loan portfolio is largely influenced by general economic conditions and trends of the counties and markets in which the debtors operate, and the resulting impact on the operations of borrowers or on the value of underlying collateral, if any. See Note 1 for the Company’s accounting policy on loans and the allowance for loan losses. A roll forward of the allowance for loan losses is summarized as follows. Years Ended December 31, (in thousands) 2018 2017 2016 Beginning balance $ 12,653 $ 11,820 $ 10,307 Provision for loan losses 1,600 2,325 1,800 Charge-offs (1,213 ) (1,604 ) (584 ) Recoveries 113 112 297 Net charge-offs (1,100 ) (1,492 ) (287 ) Ending balance $ 13,153 $ 12,653 $ 11,820 The following tables present the balance and activity in the ALLL by portfolio segment and the recorded investment in loans by portfolio segment for the year ended December 31, 2018 . TOTAL – Year Ended December 31, 2018 (in thousands) Commercial & industrial Owner- occupied CRE AG production AG real estate CRE investment Construction & land development Residential construction Residential first mortgage Residential junior mortgage Retail & other Total ALLL: Beginning balance $ 4,934 $ 2,607 $ 129 $ 296 $ 1,388 $ 726 $ 251 $ 1,609 $ 488 $ 225 $ 12,653 Provision 1,107 300 (8 ) 5 119 (216 ) (40 ) 117 (51 ) 267 1,600 Charge-offs (813 ) (74 ) — — (37 ) — — (85 ) — (204 ) (1,213 ) Recoveries 43 14 — — — — — 5 35 16 113 Net charge-offs (770 ) (60 ) — — (37 ) — — (80 ) 35 (188 ) (1,100 ) Ending balance $ 5,271 $ 2,847 $ 121 $ 301 $ 1,470 $ 510 $ 211 $ 1,646 $ 472 $ 304 $ 13,153 As % of ALLL 40.1 % 21.6 % 0.9 % 2.3 % 11.2 % 3.9 % 1.6 % 12.5 % 3.6 % 2.3 % 100.0 % ALLL: Individually evaluated $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — Collectively evaluated 5,271 2,847 121 301 1,470 510 211 1,646 472 304 13,153 Ending balance $ 5,271 $ 2,847 $ 121 $ 301 $ 1,470 $ 510 $ 211 $ 1,646 $ 472 $ 304 $ 13,153 Loans: Individually evaluated $ 2,927 $ 1,506 $ — $ 222 $ 1,686 $ 603 $ — $ 2,750 $ 233 $ 12 $ 9,939 Collectively evaluated 681,993 439,847 35,625 53,222 341,966 79,996 30,926 355,091 111,095 26,481 2,156,242 Total loans $ 684,920 $ 441,353 $ 35,625 $ 53,444 $ 343,652 $ 80,599 $ 30,926 $ 357,841 $ 111,328 $ 26,493 $ 2,166,181 Less ALLL 5,271 2,847 121 301 1,470 510 211 1,646 472 304 13,153 Net loans $ 679,649 $ 438,506 $ 35,504 $ 53,143 $ 342,182 $ 80,089 $ 30,715 $ 356,195 $ 110,856 $ 26,189 $ 2,153,028 As a further breakdown, the ALLL is summarized by originated and acquired as follows. Originated – Year Ended December 31, 2018 (in thousands) Commercial & industrial Owner- occupied CRE AG production AG real estate CRE investment Construction & land development Residential construction Residential first mortgage Residential junior mortgage Retail & other Total ALLL: Beginning balance $ 4,192 $ 2,115 $ 112 $ 235 $ 1,154 $ 628 $ 200 $ 1,297 $ 409 $ 200 $ 10,542 Provision 1,262 385 (2 ) 20 113 (197 ) 11 187 (31 ) 266 2,014 Charge-offs (813 ) (64 ) — — (37 ) — — (85 ) — (201 ) (1,200 ) Recoveries 42 3 — — — — — 1 30 16 92 Net charge-offs (771 ) (61 ) — — (37 ) — — (84 ) 30 (185 ) (1,108 ) Ending balance $ 4,683 $ 2,439 $ 110 $ 255 $ 1,230 $ 431 $ 211 $ 1,400 $ 408 $ 281 $ 11,448 As % of ALLL 40.9 % 21.3 % 1.0 % 2.2 % 10.7 % 3.8 % 1.8 % 12.2 % 3.6 % 2.5 % 100.0 % ALLL: Individually evaluated $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — Collectively evaluated 4,683 2,439 110 255 1,230 431 211 1,400 408 281 11,448 Ending balance $ 4,683 $ 2,439 $ 110 $ 255 $ 1,230 $ 431 $ 211 $ 1,400 $ 408 $ 281 $ 11,448 Loans: Individually evaluated $ 227 $ 321 $ — $ — $ — $ — $ — $ — $ — $ — $ 548 Collectively evaluated 567,873 283,210 11,113 31,374 171,087 66,478 30,926 220,368 78,379 23,809 1,484,617 Total loans $ 568,100 $ 283,531 $ 11,113 $ 31,374 $ 171,087 $ 66,478 $ 30,926 $ 220,368 $ 78,379 $ 23,809 $ 1,485,165 Less ALLL 4,683 2,439 110 255 1,230 431 211 1,400 408 281 11,448 Net loans $ 563,417 $ 281,092 $ 11,003 $ 31,119 $ 169,857 $ 66,047 $ 30,715 $ 218,968 $ 77,971 $ 23,528 $ 1,473,717 Acquired – Year Ended December 31, 2018 (in thousands) Commercial & industrial Owner- occupied CRE AG production AG real estate CRE investment Construction & land development Residential construction Residential first mortgage Residential junior mortgage Retail & other Total ALLL: Beginning balance $ 742 $ 492 $ 17 $ 61 $ 234 $ 98 $ 51 $ 312 $ 79 $ 25 $ 2,111 Provision (155 ) (85 ) (6 ) (15 ) 6 (19 ) (51 ) (70 ) (20 ) 1 (414 ) Charge-offs — (10 ) — — — — — — — (3 ) (13 ) Recoveries 1 11 — — — — — 4 5 — 21 Net charge-offs 1 1 — — — — — 4 5 (3 ) 8 Ending balance $ 588 $ 408 $ 11 $ 46 $ 240 $ 79 $ — $ 246 $ 64 $ 23 $ 1,705 As % of ALLL 34.5 % 23.9 % 0.6 % 2.7 % 14.1 % 4.6 % — % 14.4 % 3.8 % 1.4 % 100.0 % ALLL: Individually evaluated $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — Collectively evaluated 588 408 11 46 240 79 — 246 64 23 1,705 Ending balance $ 588 $ 408 $ 11 $ 46 $ 240 $ 79 $ — $ 246 $ 64 $ 23 $ 1,705 Loans: Individually evaluated $ 2,700 $ 1,185 $ — $ 222 $ 1,686 $ 603 $ — $ 2,750 $ 233 $ 12 $ 9,391 Collectively evaluated 114,120 156,637 24,512 21,848 170,879 13,518 — 134,723 32,716 2,672 671,625 Total loans $ 116,820 $ 157,822 $ 24,512 $ 22,070 $ 172,565 $ 14,121 $ — $ 137,473 $ 32,949 $ 2,684 $ 681,016 Less ALLL 588 408 11 46 240 79 — 246 64 23 1,705 Net loans $ 116,232 $ 157,414 $ 24,501 $ 22,024 $ 172,325 $ 14,042 $ — $ 137,227 $ 32,885 $ 2,661 $ 679,311 For comparison, the following tables present the balance and activity in the ALLL by portfolio segment and the recorded investment in loans by portfolio segment for the year ended December 31, 2017 . TOTAL – Year Ended December 31, 2017 (in thousands) Commercial & industrial Owner- occupied CRE AG production AG real estate CRE investment Construction & land development Residential construction Residential first mortgage Residential junior mortgage Retail & other Total ALLL: Beginning balance $ 3,919 $ 2,867 $ 150 $ 285 $ 1,124 $ 774 $ 304 $ 1,784 $ 461 $ 152 $ 11,820 Provision 2,419 (290 ) (21 ) 11 263 (35 ) (53 ) (192 ) 96 127 2,325 Charge-offs (1,442 ) — — — — (13 ) — (8 ) (72 ) (69 ) (1,604 ) Recoveries 38 30 — — 1 — — 25 3 15 112 Net charge-offs (1,404 ) 30 — — 1 (13 ) — 17 (69 ) (54 ) (1,492 ) Ending balance $ 4,934 $ 2,607 $ 129 $ 296 $ 1,388 $ 726 $ 251 $ 1,609 $ 488 $ 225 $ 12,653 As % of ALLL 39.0 % 20.6 % 1.0 % 2.3 % 11.0 % 5.7 % 2.0 % 12.7 % 3.9 % 1.8 % 100.0 % ALLL: Individually evaluated $ 163 $ — $ — $ — $ — $ — $ — $ — $ — $ — $ 163 Collectively evaluated 4,771 2,607 129 296 1,388 726 251 1,609 488 225 12,490 Ending balance $ 4,934 $ 2,607 $ 129 $ 296 $ 1,388 $ 726 $ 251 $ 1,609 $ 488 $ 225 $ 12,653 Loans: Individually evaluated $ 5,870 $ 1,689 $ — $ 248 $ 5,290 $ 1,053 $ 80 $ 2,801 $ 178 $ 12 $ 17,221 Collectively evaluated 631,467 428,354 35,455 51,530 309,173 88,607 36,915 360,551 105,849 22,803 2,070,704 Total loans $ 637,337 $ 430,043 $ 35,455 $ 51,778 $ 314,463 $ 89,660 $ 36,995 $ 363,352 $ 106,027 $ 22,815 $ 2,087,925 Less ALLL 4,934 2,607 129 296 1,388 726 251 1,609 488 225 12,653 Net loans $ 632,403 $ 427,436 $ 35,326 $ 51,482 $ 313,075 $ 88,934 $ 36,744 $ 361,743 $ 105,539 $ 22,590 $ 2,075,272 As a further breakdown, the December 31, 2017 ALLL is summarized by originated and acquired as follows. Originated – Year Ended December 31, 2017 (in thousands) Commercial & industrial Owner- occupied CRE AG production AG real estate CRE investment Construction & land development Residential construction Residential first mortgage Residential junior mortgage Retail & other Total ALLL: Beginning balance $ 3,150 $ 2,263 $ 122 $ 222 $ 893 $ 656 $ 266 $ 1,372 $ 373 $ 132 $ 9,449 Provision 2,429 (172 ) (10 ) 13 261 (28 ) (66 ) (69 ) 105 122 2,585 Charge-offs (1,388 ) — — — — — — (8 ) (72 ) (69 ) (1,537 ) Recoveries 1 24 — — — — — 2 3 15 45 Net charge-offs (1,387 ) 24 — — — — — (6 ) (69 ) (54 ) (1,492 ) Ending balance $ 4,192 $ 2,115 $ 112 $ 235 $ 1,154 $ 628 $ 200 $ 1,297 $ 409 $ 200 $ 10,542 As % of ALLL 39.8 % 20.1 % 1.1 % 2.2 % 10.9 % 6.0 % 1.9 % 12.3 % 3.9 % 1.8 % 100.0 % ALLL: Individually evaluated $ 163 $ — $ — $ — $ — $ — $ — $ — $ — $ — $ 163 Collectively evaluated 4,029 2,115 112 235 1,154 628 200 1,297 409 200 10,379 Ending balance $ 4,192 $ 2,115 $ 112 $ 235 $ 1,154 $ 628 $ 200 $ 1,297 $ 409 $ 200 $ 10,542 Loans: Individually evaluated $ 2,189 $ — $ — $ — $ 549 $ — $ — $ 253 $ 12 $ — $ 3,003 Collectively evaluated 486,411 237,548 11,102 27,831 113,313 56,061 33,615 190,933 65,631 18,254 1,240,699 Total loans $ 488,600 $ 237,548 $ 11,102 $ 27,831 $ 113,862 $ 56,061 $ 33,615 $ 191,186 $ 65,643 $ 18,254 $ 1,243,702 Less ALLL 4,192 2,115 112 235 1,154 628 200 1,297 409 200 10,542 Net loans $ 484,408 $ 235,433 $ 10,990 $ 27,596 $ 112,708 $ 55,433 $ 33,415 $ 189,889 $ 65,234 $ 18,054 $ 1,233,160 Acquired – Year Ended December 31, 2017 (in thousands) Commercial & industrial Owner- occupied CRE AG production AG real estate CRE investment Construction & land development Residential construction Residential first mortgage Residential junior mortgage Retail & other Total ALLL: Beginning balance $ 769 $ 604 $ 28 $ 63 $ 231 $ 118 $ 38 $ 412 $ 88 $ 20 $ 2,371 Provision (10 ) (118 ) (11 ) (2 ) 2 (7 ) 13 (123 ) (9 ) 5 (260 ) Charge-offs (54 ) — — — — (13 ) — — — — (67 ) Recoveries 37 6 — — 1 — — 23 — — 67 Net charge-offs (17 ) 6 — — 1 (13 ) — 23 — — — Ending balance $ 742 $ 492 $ 17 $ 61 $ 234 $ 98 $ 51 $ 312 $ 79 $ 25 $ 2,111 As % of ALLL 35.1 % 23.3 % 0.8 % 2.9 % 11.1 % 4.6 % 2.4 % 14.8 % 3.7 % 1.3 % 100.0 % ALLL: Individually evaluated $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — Collectively evaluated 742 492 17 61 234 98 51 312 79 25 2,111 Ending balance $ 742 $ 492 $ 17 $ 61 $ 234 $ 98 $ 51 $ 312 $ 79 $ 25 $ 2,111 Loans: Individually evaluated $ 3,681 $ 1,689 $ — $ 248 $ 4,741 $ 1,053 $ 80 $ 2,548 $ 166 $ 12 $ 14,218 Collectively evaluated 145,056 190,806 24,353 23,699 195,860 32,546 3,300 169,618 40,218 4,549 830,005 Total loans $ 148,737 $ 192,495 $ 24,353 $ 23,947 $ 200,601 $ 33,599 $ 3,380 $ 172,166 $ 40,384 $ 4,561 $ 844,223 Less ALLL 742 492 17 61 234 98 51 312 79 25 2,111 Net loans $ 147,995 $ 192,003 $ 24,336 $ 23,886 $ 200,367 $ 33,501 $ 3,329 $ 171,854 $ 40,305 $ 4,536 $ 842,112 The following tables present nonaccrual loans by portfolio segment in total and then as a further breakdown by originated or acquired. Total Nonaccrual Loans (in thousands) December 31, 2018 % to Total December 31, 2017 % to Total Commercial & industrial $ 2,816 52 % $ 6,016 46 % Owner-occupied CRE 673 12 533 4 AG production — — — — AG real estate 164 3 186 1 CRE investment 210 4 4,531 35 Construction & land development 80 1 — — Residential construction 1 — 80 1 Residential first mortgage 1,265 23 1,587 12 Residential junior mortgage 262 5 158 1 Retail & other — — 4 — Nonaccrual loans $ 5,471 100 % $ 13,095 100 % Percent of total loans 0.2 % 0.6 % December 31, 2018 December 31, 2017 (in thousands) Originated Amount % of Total Acquired Amount % of Total Originated Amount % of Total Acquired Amount % of Total Commercial & industrial $ 352 25 % $ 2,464 61 % $ 2,296 70 % $ 3,720 38 % Owner-occupied CRE 362 26 311 8 86 3 447 4 AG production — — — — — — — — AG real estate — — 164 4 — — 186 2 CRE investment — — 210 5 549 17 3,982 41 Construction & land development — — 80 2 — — — — Residential construction 1 — — — — — 80 1 Residential first mortgage 629 45 636 15 331 10 1,256 13 Residential junior mortgage 65 4 197 5 12 — 146 1 Retail & other — — — — 4 — — — Nonaccrual loans $ 1,409 100 % $ 4,062 100 % $ 3,278 100 % $ 9,817 100 % Percent of nonaccrual loans 25.8 % 74.2 % 25.0 % 75.0 % The following tables present past due loans by portfolio segment. December 31, 2018 (in thousands) 30-89 Days Past Due (accruing) 90 Days & Over or nonaccrual Current Total Commercial & industrial $ — $ 2,816 $ 682,104 $ 684,920 Owner-occupied CRE 557 673 440,123 441,353 AG production 19 — 35,606 35,625 AG real estate 35 164 53,245 53,444 CRE investment 180 210 343,262 343,652 Construction & land development — 80 80,519 80,599 Residential construction — 1 30,925 30,926 Residential first mortgage 758 1,265 355,818 357,841 Residential junior mortgage 12 262 111,054 111,328 Retail & other 10 — 26,483 26,493 Total loans $ 1,571 $ 5,471 $ 2,159,139 $ 2,166,181 Percent of total loans 0.1 % 0.2 % 99.7 % 100.0 % December 31, 2017 (in thousands) 30-89 Days Past Due (accruing) 90 Days & Over or nonaccrual Current Total Commercial & industrial $ 211 $ 6,016 $ 631,110 $ 637,337 Owner-occupied CRE 671 533 428,839 430,043 AG production 30 — 35,425 35,455 AG real estate — 186 51,592 51,778 CRE investment — 4,531 309,932 314,463 Construction & land development 76 — 89,584 89,660 Residential construction 587 80 36,328 36,995 Residential first mortgage 1,039 1,587 360,726 363,352 Residential junior mortgage 14 158 105,855 106,027 Retail & other 4 4 22,807 22,815 Total loans $ 2,632 $ 13,095 $ 2,072,198 $ 2,087,925 Percent of total loans 0.1 % 0.6 % 99.3 % 100.0 % A description of the loan risk categories used by the Company follows. Grades 1-4, Pass: Credits exhibit adequate cash flows, appropriate management and financial ratios within industry norms and/or are supported by sufficient collateral. Some credits in these rating categories may require a need for monitoring but elements of concern are not severe enough to warrant an elevated rating. Grade 5, Watch: Credits with this rating are adequately secured and performing but are being monitored due to the presence of various short-term weaknesses which may include unexpected, short-term adverse financial performance, managerial problems, potential impact of a decline in the entire industry or local economy and delinquency issues. Loans to individuals or loans supported by guarantors with marginal net worth or collateral may be included in this rating category. Grade 6, Special Mention: Credits with this rating have potential weaknesses that, without the Company’s attention and correction may result in deterioration of repayment prospects. These assets are considered Criticized Assets. Potential weaknesses may include adverse financial trends for the borrower or industry, repeated lack of compliance with Company requests, increasing debt to net worth, serious management conditions and decreasing cash flow. Grade 7, Substandard: Assets with this rating are characterized by the distinct possibility the Company will sustain some loss if deficiencies are not corrected. All foreclosures, liquidations, and nonaccrual loans are considered to be categorized in this rating, regardless of collateral sufficiency. Grade 8, Doubtful: Assets with this rating exhibit all the weaknesses as one rated Substandard with the added characteristic that such weaknesses make collection or liquidation in full highly questionable. Grade 9, Loss: Assets in this category are considered uncollectible. Pursuing any recovery or salvage value is impractical but does not preclude partial recovery in the future. The following tables present total loans by risk categories. December 31, 2018 (in thousands) Grades 1- 4 Grade 5 Grade 6 Grade 7 Grade 8 Grade 9 Total Commercial & industrial $ 649,475 $ 16,145 $ 6,178 $ 13,122 $ — $ — $ 684,920 Owner-occupied CRE 405,198 22,776 6,569 6,810 — — 441,353 AG production 29,363 3,302 2,351 609 — — 35,625 AG real estate 46,248 3,246 2,983 967 — — 53,444 CRE investment 334,080 6,792 — 2,780 — — 343,652 Construction & land development 75,365 5,138 16 80 — — 80,599 Residential construction 30,926 — — — — — 30,926 Residential first mortgage 353,239 1,406 510 2,686 — — 357,841 Residential junior mortgage 111,037 17 — 274 — — 111,328 Retail & other 26,493 — — — — — 26,493 Total loans $ 2,061,424 $ 58,822 $ 18,607 $ 27,328 $ — $ — $ 2,166,181 Percent of total loans 95.1 % 2.7 % 0.9 % 1.3 % — % — % 100.0 % December 31, 2017 (in thousands) Grades 1- 4 Grade 5 Grade 6 Grade 7 Grade 8 Grade 9 Total Commercial & industrial $ 597,854 $ 12,999 $ 16,129 $ 10,355 $ — $ — $ 637,337 Owner-occupied CRE 397,357 23,340 6,442 2,904 — — 430,043 AG production 30,431 4,000 — 1,024 — — 35,455 AG real estate 44,321 4,873 — 2,584 — — 51,778 CRE investment 299,926 8,399 190 5,948 — — 314,463 Construction & land development 86,011 2,758 17 874 — — 89,660 Residential construction 36,915 — — 80 — — 36,995 Residential first mortgage 358,067 1,868 683 2,734 — — 363,352 Residential junior mortgage 105,736 117 — 174 — — 106,027 Retail & other 22,811 — — 4 — — 22,815 Total loans $ 1,979,429 $ 58,354 $ 23,461 $ 26,681 $ — $ — $ 2,087,925 Percent of total loans 94.8 % 2.8 % 1.1 % 1.3 % — % — % 100.0 % The following tables present impaired loans. December 31, 2018 (in thousands) Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized Commercial & industrial $ 2,927 $ 6,736 $ — $ 4,041 $ 660 Owner-occupied CRE 1,506 1,833 — 1,659 137 AG production — — — — — AG real estate 222 281 — 238 26 CRE investment 1,686 2,484 — 1,606 163 Construction & land development 603 1,506 — 603 21 Residential construction — — — — — Residential first mortgage 2,750 2,907 — 2,478 176 Residential junior mortgage 233 262 — 62 15 Retail & other 12 12 — 12 1 Total $ 9,939 $ 16,021 $ — $ 10,699 $ 1,199 Originated impaired loans $ 548 $ 548 $ — $ 899 $ 154 Acquired impaired loans 9,391 15,473 — 9,800 1,045 Total $ 9,939 $ 16,021 $ — $ 10,699 $ 1,199 December 31, 2017 (in thousands) Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized Commercial & industrial $ 5,870 $ 10,063 $ 163 $ 6,586 $ 718 Owner-occupied CRE 1,689 2,256 — 1,333 132 AG production — 10 — — — AG real estate 248 307 — 233 26 CRE investment 5,290 8,102 — 5,411 465 Construction & land development 1,053 1,053 — 813 57 Residential construction 80 983 — 91 27 Residential first mortgage 2,801 3,653 — 2,177 180 Residential junior mortgage 178 507 — 154 17 Retail & other 12 14 — 12 1 Total $ 17,221 $ 26,948 $ 163 $ 16,810 $ 1,623 Originated impaired loans $ 3,003 $ 3,003 $ 163 $ 2,964 $ 241 Acquired impaired loans 14,218 23,945 — 13,846 1,382 Total $ 17,221 $ 26,948 $ 163 $ 16,810 $ 1,623 Total purchased credit impaired loans (in aggregate since the Company’s 2013 acquisitions) were initially recorded at a fair value of $43.6 million on their respective acquisition dates, net of an initial $34.4 million nonaccretable mark and a zero accretable mark. At December 31, 2018 , $9.4 million of the $43.6 million remain in impaired loans. Nonaccretable discount on PCI loans: Years Ended December 31, (in thousands) 2018 2017 Balance at beginning of period $ 9,471 $ 14,327 Acquired balance, net — 8,352 Accretion to loan interest income (1,976 ) (7,995 ) Transferred to accretable (990 ) (1,936 ) Disposals of loans (97 ) (3,277 ) Balance at end of period $ 6,408 $ 9,471 Troubled Debt Restructurings At December 31, 2018 , there were four loans classified as troubled debt restructurings with a current outstanding balance of $0.6 million and a pre-modification balance of $2.7 million . In comparison, at December 31, 2017 , there were eight loans classified as troubled debt restructurings with an outstanding balance of $5.6 million and a pre-modification balance of $6.9 million . There were no loans which were classified as troubled debt restructurings during the previous twelve months that subsequently defaulted during 2018 . As of December 31, 2018 , there were no commitments to lend additional funds to debtors whose terms have been modified in troubled debt restructurings.

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, less accumulated depreciation and amortization, is summarized as follows. (in thousands) December 31, 2018 December 31, 2017 Land $ 6,220 $ 5,987 Land improvements 3,842 3,591 Building and improvements 42,238 39,661 Leasehold improvements 4,092 4,092 Furniture and equipment 18,590 16,342 74,982 69,673 Less accumulated depreciation and amortization 26,809 22,522 Premises and equipment, net $ 48,173 $ 47,151 Depreciation and amortization expense amounted to $4.4 million in 2018 , $4.2 million in 2017 , and $3.2 million in 2016 . The Company and certain of its subsidiaries are obligated under non-cancelable operating leases for facilities, certain of which provide for increased rentals based upon increases in cost of living adjustments and other indices. Rent expense under leases totaled $1.4 million in 2018 , $1.1 million in 2017 , and $0.8 million in 2016 . At December 31, 2018 , the approximate minimum annual rentals under these non-cancelable lease agreements with remaining terms in excess of one year are as follows. Years Ending December 31, (in thousands) 2019 $ 1,073 2020 1,065 2021 956 2022 902 2023 665 Thereafter 742 Total $ 5,403 During the second quarter of 2016, a $1.7 million lease termination liability and charge to other expense was recorded due to the closure of a branch, concurrent with the consummation date of the Baylake merger. Payments are expected to continue to the lessor for the remainder of the lease term. Since the remaining lease payments have been recognized against earnings, these remaining lease payments were excluded from the above table.

GOODWILL AND OTHER INTANGIBLES

GOODWILL AND OTHER INTANGIBLES AND MORTGAGE SERVICING RIGHTS	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND OTHER INTANGIBLES AND MORTGAGE SERVICING RIGHTS	GOODWILL AND OTHER INTANGIBLES AND MORTGAGE SERVICING RIGHTS A summary of goodwill and other intangibles was as follows. (in thousands) December 31, 2018 December 31, 2017 Goodwill $ 107,366 $ 107,366 Core deposit intangibles 12,562 16,477 Customer list intangibles 4,379 4,563 Other intangibles 16,941 21,040 Goodwill and other intangibles, net $ 124,307 $ 128,406 Goodwill : Goodwill was $107.4 million at both December 31, 2018 and December 31, 2017 . During 2017, goodwill increased due to the First Menasha acquisition. See Note 1 for the Company’s accounting policy for goodwill and see Note 2 for additional information on the Company’s acquisitions. Other intangibles : Other intangible assets, consisting of core deposit intangibles and customer list intangibles, are amortized over their estimated finite lives. During 2018, customer list intangibles increased due to the purchase of a brokerage book of business, while during 2017, core deposit intangibles increased due to the First Menasha acquisition and customer list intangibles increased due to a modification to the contingent earn-out payment on the financial advisor business acquired in 2016, fixing the previously variable earn-out payment on a portion of the purchase price. See Note 1 for the Company’s accounting policy for other intangibles and see Note 2 for additional information on the Company’s acquisitions. (in thousands) December 31, 2018 December 31, 2017 Core deposit intangibles: Gross carrying amount $ 29,015 $ 29,015 Accumulated amortization (16,453 ) (12,538 ) Net book value $ 12,562 $ 16,477 Additions during the period $ — $ 3,670 Amortization during the period $ 3,915 $ 4,294 Customer list intangibles: Gross carrying amount $ 5,523 5,233 Accumulated amortization (1,144 ) (670 ) Net book value $ 4,379 $ 4,563 Additions during the period $ 290 $ 870 Amortization during the period $ 474 $ 401 Mortgage servicing rights : A summary of the changes in the MSR asset was as follows. (in thousands) December 31, 2018 December 31, 2017 MSR asset: MSR asset at beginning of year $ 3,187 $ 1,922 Capitalized MSR 1,203 876 MSR asset acquired — 874 Amortization during the period (641 ) (485 ) MSR asset at end of year $ 3,749 $ 3,187 Fair value of MSR asset at end of period $ 6,347 $ 4,097 Residential mortgage loans serviced for others $ 603,446 $ 518,419 Net book value of MSR asset to loans serviced for others 0.62 % 0.61 % The Company periodically evaluates its mortgage servicing rights asset for impairment. No valuation allowance or impairment charge was recorded for 2018 or 2017 . See Note 1 for the Company’s accounting policy for MSRs, see Note 2 for additional information on the Company’s acquisitions, and see Note 18 for additional information on the fair value of the MSR asset. The following table shows the estimated future amortization expense for amortizing intangible assets and the MSR asset. The projections are based on existing asset balances, the current interest rate environment and prepayment speeds as of December 31, 2018 . The actual amortization expense the Company recognizes in any given period may be significantly different depending upon acquisition or sale activities, changes in interest rates, prepayment speeds, market conditions, regulatory requirements and events or circumstances that indicate the carrying amount of an asset may not be recoverable. (in thousands) Core deposit intangibles Customer list intangibles MSR asset Years Ending December 31, 2019 $ 3,337 $ 507 $ 697 2020 2,657 507 680 2021 2,167 507 531 2022 1,735 507 531 2023 1,273 483 419 Thereafter 1,393 1,868 891 Total $ 12,562 $ 4,379 $ 3,749

OTHER REAL ESTATE OWNED

OTHER REAL ESTATE OWNED	12 Months Ended
	Dec. 31, 2018
Real Estate [Abstract]
OTHER REAL ESTATE OWNED	OTHER REAL ESTATE OWNED A summary of OREO, which is included in other assets in the consolidated balance sheets, for the periods indicated is as follows. Years Ended December 31, (in thousands) 2018 2017 Balance at beginning of period $ 1,294 $ 2,059 Transfers in at net realizable value 607 583 Sales proceeds (2,824 ) (1,724 ) Net gain from sales 1,032 258 Write-downs (120 ) (127 ) Additions for new construction 431 — Acquired balance, net — 245 Balance at end of period $ 420 $ 1,294

DEPOSITS

DEPOSITS	12 Months Ended
	Dec. 31, 2018
Deposits [Abstract]
DEPOSITS	DEPOSITS At December 31, 2018 , the scheduled maturities of time deposits were as follows. Years Ending December 31, (in thousands) 2019 $ 260,993 2020 89,948 2021 22,847 2022 14,760 2023 15,088 Thereafter — Total time deposits $ 403,636 Time deposits of $250,000 or more were $77.6 million and $50.4 million at December 31, 2018 and 2017 , respectively.

SHORT AND LONG-TERM BORROWINGS

SHORT AND LONG-TERM BORROWINGS	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
SHORT AND LONG-TERM BORROWINGS	SHORT AND LONG-TERM BORROWINGS Short-Term Borrowings: The Company did not have any short-term borrowings (borrowing with an original contractual maturity of one year or less) outstanding at December 31, 2018 or 2017 . Long-Term Borrowings: The components of long-term borrowings (borrowing with an original contractual maturity greater than one year) were as follows. (in thousands) December 31, 2018 December 31, 2017 FHLB advances $ 35,252 $ 36,509 Junior subordinated debentures 30,096 29,616 Subordinated notes 11,957 11,921 Total long-term borrowings $ 77,305 $ 78,046 FHLB Advances : The FHLB advances bear fixed rates, require interest-only monthly payments, and have maturity dates through November 2022. The weighted average rate of the FHLB advances was 1.72% and 1.71% at December 31, 2018 and 2017 , respectively. The FHLB advances are collateralized by a blanket lien on qualifying first mortgages, home equity loans, multi-family loans and certain farmland loans which had a pledged balance of $295.3 million and $313.5 million at December 31, 2018 and 2017 , respectively. The following table shows the maturity schedule of the FHLB advances as of December 31, 2018 . Maturing in: (in thousands) 2019 $ — 2020 10,000 2021 — 2022 25,252 2023 — $ 35,252 The Company has a $10 million line of credit with a third party bank, bearing a variable rate of interest based on one-month LIBOR plus a margin, but subject to a floor rate, with quarterly payments of interest only. At December 31, 2018 , the available line was $10 million and the rate was one-month LIBOR plus 2.25% with a 3.25% floor. The outstanding balance was zero at December 31, 2018 and 2017 , and the line was not used during 2018 or 2017 . Junior Subordinated Debentures : The following table shows the breakdown of junior subordinated debentures. Interest on all debentures is current. Any applicable discounts (initially recorded to carry an acquired debenture at its then estimated fair market value) are being accreted to interest expense over the remaining life of the debentures. All the debentures below are currently callable and may be redeemed in part or in full plus any accrued but unpaid interest. Junior Subordinated Debentures (in thousands) Maturity Date Par 12/31/2018 Unamortized Discount 12/31/2018 Carrying Value 12/31/2017 Carrying Value 2004 Nicolet Bankshares Statutory Trust (1) 7/15/2034 $ 6,186 $ — $ 6,186 $ 6,186 2005 Mid-Wisconsin Financial Services, Inc. (2) 12/15/2035 10,310 (3,371 ) 6,939 6,739 2006 Baylake Corp. (3) 9/30/2036 16,598 (4,120 ) 12,478 12,242 2004 First Menasha Bancshares, Inc. (4) 3/17/2034 5,155 (662 ) 4,493 4,449 Total $ 38,249 $ (8,153 ) $ 30,096 $ 29,616 (1) The interest rate is 8.00% fixed. (2) The debentures, assumed in April 2013 as the result of an acquisition, have a floating rate of the three-month LIBOR plus 1.43% , adjusted quarterly. The interest rates were 4.22% and 3.02% as of December 31, 2018 and 2017 , respectively. (3) The debentures, assumed in April 2016 as a result of an acquisition, have a floating rate of the three-month LIBOR plus 1.35% , adjusted quarterly. The interest rates were 4.15% and 3.04% as of December 31, 2018 and 2017 , respectively. (4) The debentures, assumed in April 2017 as the result of an acquisition, have a floating rate of the three-month LIBOR plus 2.79% , adjusted quarterly. The interest rate was 5.58% and 4.39% as of December 31, 2018 and 2017 , respectively. Each of the junior subordinated debentures was issued to an underlying statutory trust (the “statutory trusts”), which issued trust preferred securities and common securities and used the proceeds from the issuance of the common and the trust preferred securities to purchase the junior subordinated debentures of the Company. The debentures represent the sole asset of the statutory trusts. All of the common securities of the statutory trusts are owned by the Company. The statutory trusts are not included in the consolidated financial statements. The net effect of all the documents entered into with respect to the trust preferred securities is that the Company, through payments on its debentures, is liable for the distributions and other payments required on the trust preferred securities. At December 31, 2018 and 2017 , $28.9 million and $28.5 million , respectively, of trust preferred securities qualify as Tier 1 capital. Subordinates Notes : In 2015, the Company placed an aggregate of $12 million in subordinated Notes in private placements with certain accredited investors. All Notes were issued with 10 -year maturities, have a fixed annual interest rate of 5% payable quarterly, are callable on or after the fifth anniversary of their respective issuances dates, and qualify for Tier 2 capital for regulatory purposes.

EMPLOYEE AND DIRECTOR BENEFIT P

EMPLOYEE AND DIRECTOR BENEFIT PLANS	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
EMPLOYEE AND DIRECTOR BENEFIT PLANS	EMPLOYEE AND DIRECTOR BENEFIT PLANS The Company sponsors two deferred compensation plans, one for certain key management employees and another for directors. Under the management plan, which was amended in 2016, employees designated by the Board of Directors may elect to defer compensation and the Company may at its discretion make nonelective contributions on behalf of one or more eligible plan participants. Upon retirement, termination of employment or at their election, the employee shall become entitled to receive the deferred amounts plus earnings thereon. The liability for the cumulative employee contributions and earnings thereon at December 31, 2018 and 2017 totaled approximately $527,000 and $152,000 , respectively, and is included in other liabilities on the consolidated balance sheets. The Company made nonelective contributions totaling $175,000 and $700,000 during 2018 and 2017 , respectively, to selected recipients, to vest and be expensed ratably over four or five years from the date of grant. Under the director plan, participating directors may defer up to 100% of their Board compensation towards the purchase of Company common stock at market prices on a quarterly basis that is held in a Rabbi Trust and distributed when each such participating director ends his or her board service. During 2018 and 2017 , the director plan purchased 3,889 and 4,427 shares of Company common stock valued at approximately $213,000 and $229,000 , respectively. Common stock valued at approximately $32,000 (and representing 600 shares) and $473,000 (and representing 9,900 shares) was distributed to past directors during 2018 and 2017 , respectively. The common stock outstanding and the related director deferred compensation liability are offsetting components of the Company’s equity in the amount of $831,000 at December 31, 2018 and $636,000 at December 31, 2017 representing 26,070 shares and 22,853 shares, respectively. The Company sponsors a 401(k) savings plan under which eligible employees may choose to save up to 100% of salary compensation on either a pre-tax or after-tax basis, subject to certain IRS limits. Under the plan, the Company matches 100% of participating employee contributions up to 6% of the participant’s gross compensation. The Company contribution vests over five years. The Company can make additional annual discretionary profit sharing contributions, as determined by the Board of Directors. During 2018 , 2017 and 2016 , the Company’s 401(k) expense was approximately $1.8 million , $2.0 million (including a $0.5 million profit sharing contribution), and $1.2 million , respectively. During 2016, the plan was amended and participants can no longer elect to buy Company common stock within their 401(k) portfolio.

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION The Company may grant stock options and restricted stock under its stock-based compensation plans to certain officers, employees and directors. These plans are administered by a committee of the Board of Directors. The Company's stock-based compensation plans at December 31, 2018 are described below. 2011 Long-Term Incentive Plan ("2011 LTIP") : The Company’s 2011 LTIP, as subsequently amended with shareholder approval, has reserved 1,500,000 shares of the Company's common stock for potential stock-based awards. This plan provides for certain stock-based awards such as, but not limited to, stock options, stock appreciation rights and restricted common stock, as well as cash performance awards. As of December 31, 2018 , approximately 127,000 shares were available for grant under this plan. 2002 Stock Incentive Plan : The Company’s 2002 Stock Incentive Plan, as subsequently amended with shareholder approval, reserved a total of 1,175,000 shares of the Company's common stock for potential stock options. This plan became fully utilized in 2012 and no further awards may be granted under this plan. Acquired Equity Incentive Plan : In 2016, the Company assumed sponsorship of an equity incentive plan of an acquired company to allow for that company's already granted awards that became exercisable upon acquisition to be honored. No further awards may be granted under this assumed plan. In general, for stock options granted the exercise price will not be less than the fair value of the Company’s common stock on the date of grant, the options will become exercisable based upon vesting terms determined by the committee, and the options will expire ten years after the date of grant. In general, for restricted stock granted the shares are issued at the fair value of the Company’s common stock on the date of grant, are restricted as to transfer, but are not restricted as to dividend payments or voting rights, and the transfer restrictions lapse over time, depending upon vesting terms provided for in the grant and contingent upon continued employment. A Black-Scholes model is utilized to estimate the fair value of stock options. See Note 1 for the Company’s accounting policy on stock-based compensation. The weighted average assumptions used in the model for valuing stock option grants were as follows. 2018 2017 2016 Dividend yield — % — % — % Expected volatility 25 % 25 % 25 % Risk-free interest rate 2.61 % 2.14 % 1.52 % Expected average life 7 years 7 years 7 years Weighted average per share fair value of options $ 17.36 $ 15.80 $ 11.04 A summary of the Company’s stock option activity is summarized below. Stock Options Option Shares Outstanding Weighted Average Exercise Price Weighted Average Remaining Life (Years) Aggregate Intrinsic Value (in thousands) Outstanding – December 31, 2015 746,004 $ 21.56 Granted 170,500 36.86 Options assumed in acquisition 91,701 21.03 Exercise of stock options * (84,723 ) 20.98 Forfeited (1,456 ) 21.71 Outstanding – December 31, 2016 922,026 $ 24.39 5.4 $ 21,483 Granted 949,500 49.93 Exercise of stock options * (209,371 ) 18.15 Forfeited (18,900 ) 35.36 Outstanding – December 31, 2017 1,643,255 $ 39.82 8.1 $ 24,525 Granted 15,500 52.76 Exercise of stock options * (70,556 ) 21.52 Forfeited (6,500 ) 39.43 Outstanding – December 31, 2018 1,581,699 $ 40.77 7.4 $ 13,825 Exercisable – December 31, 2018 599,011 $ 32.77 6.3 $ 9,798 *The terms of the stock option agreements permit having a number of shares of stock withheld, the fair market value of which as of the date of exercise is sufficient to satisfy the exercise price and/or tax withholding requirements, and accordingly 6,411 shares, 85,422 shares, and 10,244 shares were surrendered during 2018 , 2017 , and 2016 , respectively. The following options were outstanding at December 31, 2018 . Number of Shares Weighted Average Exercise Price Weighted Average Remaining Life (Years) Outstanding Exercisable Outstanding Exercisable Outstanding Exercisable $9.19 – $20.00 99,267 85,579 $ 16.39 $ 16.38 2.0 1.8 $20.01 – $25.00 202,268 160,468 23.77 23.77 5.8 5.8 $25.01 – $30.00 142,294 87,494 25.97 26.01 6.1 6.1 $30.01 – $40.00 180,370 77,070 35.95 35.41 7.4 7.3 $40.01 – $56.43 957,500 188,400 49.99 49.94 8.5 8.4 1,581,699 599,011 $ 40.77 $ 32.77 7.4 6.3 Intrinsic value represents the amount by which the fair market value of the underlying stock exceeds the exercise price of the stock options. The intrinsic value of options exercised in 2018 , 2017 , and 2016 was approximately $2.2 million , $7.5 million , and $1.3 million , respectively. A summary of the Company’s restricted stock activity is summarized below. Restricted Stock Restricted Shares Outstanding Weighted Average Grant Date Fair Value Outstanding – December 31, 2015 36,690 $ 18.70 Granted 31,466 33.68 Vested * (25,207 ) 23.58 Forfeited — — Outstanding – December 31, 2016 42,949 $ 26.80 Granted 9,240 57.75 Vested * (20,514 ) 29.87 Forfeited (755 ) 16.50 Outstanding – December 31, 2017 30,920 $ 34.26 Granted 18,256 52.55 Vested * (19,661 ) 43.58 Forfeited (3 ) 16.50 Outstanding – December 31, 2018 29,512 $ 39.37 *The terms of the restricted stock agreements permit the surrender of shares to the Company upon vesting in order to satisfy applicable tax withholding at the minimum statutory withholding rate, and accordingly 3,948 shares, 5,266 shares, and 7,851 shares were surrendered during 2018 , 2017 , and 2016 , respectively. The Company recognized $4.7 million , $3.1 million and $1.6 million of stock-based compensation expense (included in personnel on the consolidated statements of income) during the years ended December 31, 2018 , 2017 , and 2016 , respectively, associated with its common stock awards granted to officers and employees. In addition, during 2018 , the Company recognized approximately $0.2 million of director expense (included in other expense on the consolidated statements of income) for a total restricted stock grant of 3,510 shares with immediate vesting to directors. As of December 31, 2018 , there was approximately $12.9 million of unrecognized compensation cost related to equity award grants. The cost is expected to be recognized over the remaining vesting period of approximately three years. The Company recognized a tax benefit of approximately $0.2 million and $1.9 million for the years ended December 31, 2018 and 2017 , respectively, for the tax impact of stock option exercises and vesting of restricted stock.

STOCKHOLDERS' EQUITY

STOCKHOLDERS' EQUITY	12 Months Ended
	Dec. 31, 2018
Stockholders' Equity Note [Abstract]
STOCKHOLDERS' EQUITY	STOCKHOLDERS' EQUITY As of December 31, 2018 , the Board of Directors has authorized the use of up to $54 million to repurchase up to 1,450,000 shares of outstanding common stock through our common stock repurchase program. During 2018 , $22.2 million was utilized to repurchase and cancel nearly 408,100 common shares at a weighted average price of $54.35 , bringing the life-to-date cumulative totals to $46.3 million to repurchase and cancel over 1.1 million common shares. As of December 31, 2018 , there remained $7.7 million authorized under the repurchase program to be utilized from time-to-time to repurchase common shares in the open market, through block transactions or in private transactions. On April 28, 2017, in connection with its acquisition of First Menasha, the Company issued 1,309,885 shares of its common stock for consideration of $62.2 million plus cash consideration of $19.3 million . Approximately $0.2 million in direct stock issuance costs for the merger were incurred and charged against additional paid-in capital. See Note 2 for additional information on the Company’s acquisitions. On April 29, 2016, in connection with its acquisition of Baylake, the Company issued 4,344,243 shares of its common stock for consideration of $163.3 million , and recorded $1.2 million consideration for assumed stock options. Approximately $0.3 million in direct stock issuance costs for the merger were incurred and charged against additional paid-in capital. In connection with the financial advisor business acquisition that completed April 1, 2016, the Company issued $2.6 million in common stock consideration.

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The current and deferred amounts of income tax expense were as follows. Years Ended December 31, (in thousands) 2018 2017 2016 Current $ 14,967 $ 10,952 $ 12,708 Deferred (1,521 ) 4,430 (3,337 ) Adjustment to the net deferred tax asset for the Tax Cuts and Jobs Act — 885 — Income tax expense $ 13,446 $ 16,267 $ 9,371 On December 22, 2017, the Tax Cuts and Jobs Act was signed into law. The new law amends the Internal Revenue Code to reduce corporate tax rates and modify various tax policies, credits, and deductions. The corporate federal tax rate was reduced from a maximum of 35% to a flat 21% rate, which is effective for the Company beginning January 1, 2018. As a result of the corporate tax rate reduction, the Company reduced its net deferred tax asset for the year ended December 31, 2017, by $885,000 , which was recognized as additional income tax expense. The differences between the income tax expense recognized and the amount computed by applying the statutory federal income tax rate (21% for 2018 and 35% for 2017 and 2016) to the income before income taxes, less noncontrolling interest, for the years ended as indicated are included in the following table. Years Ended December 31, (in thousands) 2018 2017 2016 Tax on pretax income, less noncontrolling interest, at statutory rates $ 11,441 $ 17,296 $ 9,742 State income taxes, net of federal effect 3,308 2,242 1,339 Tax-exempt interest income (574 ) (1,073 ) (769 ) Non-deductible interest disallowance 30 28 18 Increase in cash surrender value life insurance (508 ) (807 ) (452 ) Non-deductible business entertainment 156 168 106 Non-deductible merger expenses — 65 18 Stock-based employee compensation (50 ) (62 ) (35 ) Adjustment to the net deferred tax asset for the Tax Cuts and Jobs Act — 885 — Deduction attributable to share-based payments — (1,854 ) — Other, net (357 ) (621 ) (596 ) Income tax expense $ 13,446 $ 16,267 $ 9,371 The net deferred tax asset includes the following amounts of deferred tax assets and liabilities. (in thousands) December 31, 2018 December 31, 2017 Deferred tax assets: ALLL $ 5,240 $ 7,806 Net operating loss carryforwards 2,202 2,694 Credit carryforwards 43 1,433 Compensation 2,408 1,818 Other 2,549 1,379 Other real estate 103 — Unrealized loss on securities AFS 1,740 794 Total deferred tax assets 14,285 15,924 Deferred tax liabilities: Premises and equipment (821 ) (954 ) Prepaid expenses (693 ) (728 ) Investment securities (1,723 ) (1,589 ) Core deposit and other intangibles (3,563 ) (4,101 ) Estimated section 382 limitation — (543 ) Purchase accounting adjustments to liabilities (2,011 ) (2,113 ) Other (1,021 ) (868 ) Total deferred tax liabilities (9,832 ) (10,896 ) Net deferred tax assets $ 4,453 $ 5,028 A valuation allowance is required if it is more likely than not that some portion of the deferred tax asset will not be realized. At December 31, 2018 and 2017 , no valuation allowance was determined to be necessary. At December 31, 2018 , the Company had a federal and state net operating loss carryforward of $4.2 million and $21.0 million , respectively. Of these amounts, the entire $4.2 million of federal net operating loss carryover and $18.8 million of the state net operating loss carryover were the result of the Company’s mergers with Mid-Wisconsin, Baylake, and First Menasha. The federal and state net operating loss carryovers resulting from the mergers have been included in the IRC section 382 limitation calculation and are being limited to the overall amount expected to be realized. The full $2.2 million state net operating loss carried over from the Company’s regular operations is expected to be utilized over the next 14 years and will not expire. The Company’s federal income tax returns are open and subject to examination from the 2015 tax return year and forward. The years open to examination by state and local government authorities varies by jurisdiction.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES The Company is 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, financial guarantees, and standby letters of credit. Such commitments may involve, to varying degrees, elements of credit risk in excess of amounts recognized on the consolidated balance sheets. See Note 1 for the Company’s accounting policy on commitments and contingencies. The Company’s exposure to credit loss in the event of nonperformance by the other party to the financial instruments for commitments to extend credit and standby letters of credit is represented by the contractual amount of those instruments. The Company uses the same credit policies in making commitments and issuing letters of credit as they do for on-balance sheet instruments. A summary of the contract or notional amount of the Company’s exposure to off-balance sheet risk was as follows. (in thousands) December 31, 2018 December 31, 2017 Commitments to extend credit $ 721,098 $ 680,307 Financial standby letters of credit 8,571 8,783 Performance standby letters of credit 7,094 9,080 Interest rate lock commitments to originate residential mortgage loans held for sale and forward commitments to sell residential mortgage loans held for sale are considered derivative instruments and the contractual amounts were $18.2 million and $6.0 million , respectively, at December 31, 2018 . The fair value of these commitments was not material at December 31, 2018 . Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Commercial-related commitments to extend credit represented 77% and 78% of the total year-end commitments for 2018 and 2017 , respectively, and were predominantly commercial lines of credit that carry a term of one year or less. The commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. Since many of the commitments are expected to expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. Financial and performance standby letters of credit are conditional commitments issued to guarantee the performance of a customer to a third party. Financial standby letters of credit are issued specifically to facilitate commerce and typically result in the commitment being drawn on when the underlying transaction is consummated between the customer and the third party, while performance standby letters of credit generally are contingent upon the failure of the customer to perform according to the terms of the underlying contract with the third party. Both of these guarantees are primarily issued to support public and private borrowing arrangements and, generally, have terms of one year or less. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities to customers. The Company holds collateral, which may include accounts receivable, inventory, property, equipment, and income-producing properties, supporting those commitments if deemed necessary. In the event the customer does not perform in accordance with the terms of the agreement with the third-party, the Company would be required to fund the commitment. The maximum potential amount of future payments the Company could be required to make is represented by the contractual amount. If the commitment is funded, the Company would be entitled to seek recovery from the customer. At December 31, 2018 and 2017 , no amounts have been recorded as liabilities for the Company’s potential obligations under these guarantees. The Company has federal funds lines available with other financial institutions where funds may be borrowed on a short-term basis at the market rate in effect at the time of the borrowing. The total federal funds lines available as of December 31, 2018 and 2017 were $175 million and $158 million , respectively. At December 31, 2018 and 2017 , the Company had no outstanding balance on these lines. In the normal course of business, the Company is involved in various legal proceedings. In the opinion of management, any liability resulting from such proceedings would not have a material adverse effect on the consolidated financial statements.

RELATED PARTY TRANSACTIONS

RELATED PARTY TRANSACTIONS	12 Months Ended
	Dec. 31, 2018
Related Party Transactions [Abstract]
RELATED PARTY TRANSACTIONS	RELATED PARTY TRANSACTIONS The Company conducts transactions, in the normal course of business, with its directors and officers, including companies in which they have a beneficial interest. It is the Company’s policy to comply with federal regulations that require that these transactions with directors and executive officers be made on substantially the same terms as those prevailing at the time made for comparable transactions to other persons. Related party loans totaled approximately $83.8 million and $67.7 million at December 31, 2018 and 2017 , respectively. As described in Note 1 , the Company has a 50% ownership in a joint venture with the Firm in connection with the Company’s headquarters facility. The Firm is considered a related party, as one of its principals is a Board member and shareholder of the Company. The Bank incurred approximately $1.1 million in annual rent expense to the joint venture during 2018 , 2017 , and 2016 . In October 2013, the Company entered into a lease for a new branch location in a facility owned by a different member of the Company’s Board and incurred less than $120,000 annually of rent expense on this facility during 2018 , 2017 , and 2016 . During 2018, this same Board member participated in a competitive bid for and was awarded the contract as general contractor for the reconstruction of a branch location. Total payments for this branch reconstruction were $956,000 , of which at least 75% of these payments were passed through to various subcontractors. In February 2016, the Company entered into a lease agreement for a non-branch location owned by a relative of a senior management team member and paid approximately $138,000 , $138,000 , and $100,000 in 2018 , 2017 , and 2016 , respectively, to the company owned by the relative. This same relative, who is employed by the Company as a financial advisor, received approximately $657,000 , $668,000 , and $420,000 in 2018 , 2017 , and 2016 , respectively, in compensation. Another relative of the same senior management team member, who is also employed by the Company as a financial advisor, received approximately $284,000 , $257,000 , and $400,000 in 2018 , 2017 , and 2016 , respectively, in compensation.

ASSET GAINS (LOSSES), NET

ASSET GAINS (LOSSES), NET	12 Months Ended
	Dec. 31, 2018
Discontinued Operations and Disposal Groups [Abstract]
ASSET GAINS (LOSSES), NET	ASSET GAINS (LOSSES), NET Components of the net gains (losses) on assets are as follows. Years Ended December 31, (in thousands) 2018 2017 2016 Gains (losses) on sales of securities AFS, net $ (212 ) $ 1,220 $ 78 Gains (losses) on equity securities, net 77 — — Gains on sales of OREO, net 1,032 258 666 Write-downs of OREO (120 ) (127 ) — Write-down of other investment — — (500 ) Gains (losses) on sales of other investments, net 187 — — Gains (losses) on sales or dispositions of other assets, net 205 678 (190 ) Asset gains (losses), net $ 1,169 $ 2,029 $ 54

REGULATORY CAPITAL REQUIREMENTS

REGULATORY CAPITAL REQUIREMENTS	12 Months Ended
	Dec. 31, 2018
Banking and Thrift [Abstract]
REGULATORY CAPITAL REQUIREMENTS	REGULATORY CAPITAL REQUIREMENTS The Company (on a consolidated basis) and the Bank are subject to various regulatory capital requirements administered by the federal banking agencies. Failure to meet minimum capital requirements can initiate certain mandatory and possibly additional discretionary actions by regulators that, if undertaken, could have a direct material effect on the Company and Bank’s financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, the Company and Bank must meet specific capital guidelines that involve quantitative measures of their assets, liabilities and certain off-balance sheet items as calculated under regulatory accounting practices. The capital amounts and classification are also subject to qualitative judgments by the regulators about components, risk-weightings, and other factors. Prompt corrective action provisions are not applicable to bank holding companies. Quantitative measures established by regulation to ensure capital adequacy require the Company and Bank to maintain minimum amounts and ratios of Total, Tier 1 and common equity Tier 1 (“CET1”) capital (as defined in the regulations) to risk-weighted assets (as defined), and Tier 1 capital (as defined) to average assets (as defined). Management believes the Company and the Bank met all capital adequacy requirements to which they are subject as of December 31, 2018 and 2017 . As of December 31, 2018 and 2017 , the most recent notifications from the regulatory agencies categorized the Bank as well-capitalized under the regulatory framework for prompt corrective action. To be categorized as well-capitalized, an institution must maintain minimum Total risk-based, Tier 1 risk-based, CET1 risk-based and Tier 1 leverage ratios as set forth in the following table. There are no conditions or events since these notifications that management believes have changed the Bank’s category. The Company’s and the Bank’s actual regulatory capital amounts and ratios are presented in the following table. Actual For Capital Adequacy Purposes To Be Well Capitalized Under Prompt Corrective Action Provisions (2) (in thousands) Amount Ratio (1) Amount Ratio (1) Amount Ratio (1) December 31, 2018 Company Total risk-based capital $ 326,235 12.9 % $ 202,836 8.0 % Tier 1 risk-based capital 301,125 11.9 152,127 6.0 Common equity Tier 1 capital 271,435 10.7 114,095 4.5 Leverage 301,125 10.4 115,483 4.0 Bank Total risk-based capital $ 274,492 10.8 % $ 202,800 8.0 % $ 253,501 10.0 % Tier 1 risk-based capital 261,339 10.3 152,100 6.0 202,800 8.0 Common equity Tier 1 capital 261,339 10.3 114,075 4.5 164,775 6.5 Leverage 261,339 9.1 115,280 4.0 144,100 5.0 December 31, 2017 Company Total risk-based capital $ 299,043 12.8 % $ 186,475 8.0 % Tier 1 risk-based capital 274,469 11.8 139,856 6.0 Common equity Tier 1 capital 245,214 10.5 104,892 4.5 Leverage 274,469 10.0 109,298 4.0 Bank Total risk-based capital $ 267,165 11.5 % $ 186,606 8.0 % $ 233,257 10.0 % Tier 1 risk-based capital 254,512 10.9 139,954 6.0 186,606 8.0 Common equity Tier 1 capital 254,512 10.9 104,966 4.5 151,617 6.5 Leverage 254,512 9.3 109,226 4.0 136,532 5.0 (1) The Total risk-based capital ratio is defined as Tier 1 capital plus tier 2 capital divided by total risk-weighted assets. The Tier 1 risk-based capital ratio is defined as Tier 1 capital divided by total risk-weighted assets. CET1 risk-based capital ratio is defined as Tier 1 capital, with deductions for goodwill and other intangible assets (other than mortgage servicing assets), net of associated deferred tax liabilities, and limitations on the inclusion of deferred tax assets, mortgage servicing assets and investments in other financial institutions, in each case as provided further in the rules, divided by total risk-weighted assets. The Leverage ratio is defined as Tier 1 capital divided by the most recent quarter’s average total assets as adjusted. (2) Prompt corrective action provisions are not applicable at the bank holding company level. Dividends declared by the Bank that exceed the retained net income for the most current year plus retained net income for the preceding two years must be approved by Federal regulatory agencies. At December 31, 2018 , the Bank had minimal capacity to pay dividends without seeking regulatory approval, as the Bank's 2018 dividends to the Company approximated its 2018 net income.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS Fair value represents the estimated price at which an orderly transaction to sell an asset or transfer a liability would take place between market participants at the measurement date under current market conditions (i.e., an exit price concept), and is a market-based measurement versus an entity-specific measurement. The Company records and/or discloses financial instruments on a fair value basis. These financial assets and financial liabilities are measured at fair value in three levels, based on the markets in which the assets and liabilities are traded and the observability of the assumptions used to determine fair value. These levels are: • Level 1 - quoted market prices in active markets for identical assets or liabilities that a company has the ability to access at the measurement date • Level 2 - inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly • Level 3 – significant unobservable inputs for the asset or liability, which are typically based on an entity’s own assumptions, as there is little, if any, related market activity In instances where the fair value measurement is based on inputs from different levels, the level within which the entire fair value measurement will be categorized is based on the lowest level input that is significant to the fair value measurement in its entirety. This assessment of the significance of an input requires management judgment. Recurring basis fair value measurements: The following table presents the balances of assets and liabilities measured at fair value on a recurring basis for the periods presented. (in thousands) Fair Value Measurements Using Measured at Fair Value on a Recurring Basis: Total Level 1 Level 2 Level 3 December 31, 2018 U.S. government agency securities $ 21,649 $ — $ 21,649 $ — State, county and municipals 160,526 — 160,460 66 Mortgage-backed securities 131,644 — 131,644 — Corporate debt securities 86,325 — 77,901 8,424 Securities AFS $ 400,144 $ — $ 391,654 $ 8,490 Other investments (equity securities) * $ 2,650 $ 2,650 $ — $ — December 31, 2017 U.S. government agency securities $ 26,209 $ — $ 26,209 $ — State, county and municipals 184,044 — 183,386 658 Mortgage-backed securities 155,532 — 155,529 3 Corporate debt securities 36,797 — 28,307 8,490 Equity securities * 2,571 2,571 — — Securities AFS $ 405,153 $ 2,571 $ 393,431 $ 9,151 *Effective January 1, 2018, the Company adopted ASU 2016-01, which requires equity securities with readily determinable fair values to be measured at fair value with changes in the fair value recognized through net income. As a result, the approximately $2.7 million current fair value of equity securities is now reflected within other investments on the consolidated balance sheets instead of securities AFS at December 31, 2018. Prior periods have not been restated for the impact of this accounting change. See Note 1 for additional information on this new accounting standard and see Note 3 additional information on the impact to securities AFS. The following is a description of the valuation methodologies used by the Company for the Securities AFS and equity securities measured at fair value on a recurring basis, noted in the tables above. Where quoted market prices on securities exchanges are available, the investments are classified as Level 1. Level 1 investments primarily include exchange-traded equity securities. If quoted market prices are not available, fair value is generally determined using prices obtained from independent pricing vendors who use pricing models (with typical inputs including benchmark yields, reported trades for similar securities, issuer spreads or relationship to other benchmark quoted securities), or discounted cash flows, and are classified as Level 2. Examples of these investments include U.S. government agency securities, mortgage-backed securities, obligations of state, county and municipals, and certain corporate debt securities. Finally, in certain cases where there is limited activity or less transparency around inputs to the estimated fair value, investments are classified within Level 3 of the hierarchy. Examples of these include private municipal bonds and corporate debt securities, which include trust preferred security investments. At December 31, 2018 and 2017 , it was determined that carrying value was the best approximation of fair value for these Level 3 securities, based primarily on the internal analysis on these securities. The following table presents the changes in Level 3 securities AFS measured at fair value on a recurring basis. (in thousands) Years Ended Level 3 Fair Value Measurements: December 31, 2018 December 31, 2017 Balance at beginning of year $ 9,151 $ 9,108 Acquired balances — 189 Paydowns/Sales/Settlements (661 ) (146 ) Balance at end of year $ 8,490 $ 9,151 Nonrecurring basis fair value measurements: The following table presents the Company’s assets measured at fair value on a nonrecurring basis, aggregated by the level in the fair value hierarchy within which those measurements fall. (in thousands) Fair Value Measurements Using Measured at Fair Value on a Nonrecurring Basis: Total Level 1 Level 2 Level 3 December 31, 2018 Impaired loans $ 9,939 $ — $ — $ 9,939 OREO 420 — — 420 MSR asset 6,347 — — 6,347 December 31, 2017 Impaired loans $ 17,058 $ — $ — $ 17,058 OREO 1,294 — — 1,294 MSR asset 4,097 — — 4,097 The following is a description of the valuation methodologies used by the Company for the items noted in the table above. For individually evaluated impaired loans, the amount of impairment is based upon the present value of expected future cash flows discounted at the loan’s effective interest rate, the estimated fair value of the underlying collateral for collateral-dependent loans, or the estimated liquidity of the note. For OREO, the fair value is based upon the estimated fair value of the underlying collateral adjusted for the expected costs to sell. To estimate the fair value of the MSR asset, the underlying serviced loan pools are stratified by interest rate tranche and term of the loan, and a valuation model is used to calculate the present value of the expected future cash flows for each stratum. The valuation model incorporates assumptions that market participants would use in estimating future net servicing income, such as costs to service, a discount rate, ancillary income, default rates and losses, and prepayment speeds. Although some of these assumptions are based on observable market data, other assumptions are based on unobservable estimates of what market participants would use to measure fair value. Financial instruments: The carrying amounts and estimated fair values of the Company's financial instruments are shown below. December 31, 2018 (in thousands) Carrying Amount Estimated Fair Value Level 1 Level 2 Level 3 Financial assets: Cash and cash equivalents $ 249,526 $ 249,526 $ 249,526 $ — $ — Certificates of deposit in other banks 993 993 — 993 — Securities AFS 400,144 400,144 — 391,654 8,490 Other investments 17,997 17,997 2,650 13,189 2,158 Loans held for sale 1,639 1,662 — 1,662 — Loans, net 2,153,028 2,139,322 — — 2,139,322 BOLI 66,310 66,310 66,310 — — MSR asset 3,749 6,347 — — 6,347 Financial liabilities: Deposits $ 2,614,138 $ 2,614,995 $ — $ — $ 2,614,995 Long-term borrowings 77,305 75,923 — 34,907 41,016 December 31, 2017 (in thousands) Carrying Amount Estimated Fair Value Level 1 Level 2 Level 3 Financial assets: Cash and cash equivalents $ 154,933 $ 154,933 $ 154,933 $ — $ — Certificates of deposit in other banks 1,746 1,746 — 1,746 — Securities AFS 405,153 405,153 2,571 393,431 9,151 Other investments 14,837 14,837 — 13,142 1,695 Loans held for sale 4,666 4,750 — 4,750 — Loans, net 2,075,272 2,068,382 — — 2,068,382 BOLI 64,453 64,453 64,453 — — MSR asset 3,187 4,097 — — 4,097 Financial liabilities: Deposits $ 2,471,064 $ 2,469,456 $ — $ — $ 2,469,456 Long-term borrowings 78,046 77,029 — 36,510 40,519 The carrying value of certain assets and liabilities such as cash and cash equivalents, BOLI, nonmaturing deposits, and short-term borrowings, approximate their estimated fair value. For those financial instruments not previously disclosed, the following is a description of the valuation methodologies used. Certificates of deposits in other banks: Fair values are estimated using discounted cash flow analysis based on current interest rates being offered by instruments with similar terms and represents a Level 2 measurement. Other investments : The valuation methodologies utilized for the exchange-traded equity securities are discussed under "Recurring basis fair value measurements" above. The carrying amount of Federal Reserve Bank, Bankers Bank, Federal Agricultural Mortgage Corporation, and FHLB stock is a reasonably accepted fair value estimate given their restricted nature. Fair value is the redeemable (carrying) value based on the redemption provisions of the instruments which is considered a Level 2 measurement. The carrying amount of the remaining other investments (particularly common stocks of companies or other banks that are not publicly traded) approximates their fair value, determined primarily by analysis of company financial statements and recent capital issuances of the respective companies or banks, if any, and represents a Level 3 measurement. Loans held for sale: The fair value estimation process for the loans held for sale portfolio is segregated by loan type. The estimated fair value was based on what secondary markets are currently offering for portfolios with similar characteristics and represents a Level 2 measurement. Loans, net : For variable-rate loans that reprice frequently and with no significant change in credit risk or other optionality, fair values are based on carrying values. Fair values for all other loans are estimated by discounting contractual cash flows using estimated market discount rates, which reflect the credit and interest rate risk inherent in the loan. Collateral-dependent impaired loans are included in loans, net. The fair value of loans is considered to be a Level 3 measurement due to internally developed discounted cash flow measurements. Deposits : The fair value of deposits with no stated maturity (such as demand deposits, savings, interest and noninterest checking, and money market accounts) is, by definition, equal to the amount payable on demand at the reporting date. Fair values for fixed-rate certificates of deposit are estimated using a discounted cash flow calculation that applies interest rates currently being offered in the market place on certificates of similar remaining maturities. Use of internal discounted cash flows provides a Level 3 fair value measurement. Long-term borrowings : The fair value of the FHLB advances is obtained from the FHLB which uses a discounted cash flow analysis based on current market rates of similar maturity debt securities and represents a Level 2 measurement. The fair values of the junior subordinated debentures and subordinated notes utilize a discounted cash flow analysis based on an estimate of current interest rates being offered by instruments with similar terms and credit quality. Since the market for these instruments is limited, the internal valuation represents a Level 3 measurement. Lending-related commitments : At December 31, 2018 and 2017 , the estimated fair value of letters of credit, interest rate lock commitments on residential mortgage loans, and outstanding mandatory commitments to sell residential mortgage loans into the secondary market were not significant. Limitations : Fair value estimates are made at a specific point in time, based on relevant market information and information about the financial instrument. These estimates do not reflect any premium or discount that could result from offering for sale at one time the Company’s entire holdings of a particular financial instrument. Fair value estimates may not be realizable in an immediate settlement of the instrument. In some instances, there are no quoted market prices for the Company’s various financial instruments, in which case fair values may be based on estimates using present value or other valuation techniques, or based on judgments regarding future expected loss experience, current economic conditions, risk characteristics of the financial instruments, or other factors. Those techniques are significantly affected by the assumptions used, including the discount rate and estimate of future cash flows. Subsequent changes in assumptions could significantly affect the estimates.

PARENT COMPANY ONLY FINANCIAL I

PARENT COMPANY ONLY FINANCIAL INFORMATION	12 Months Ended
	Dec. 31, 2018
Condensed Financial Information Disclosure [Abstract]
PARENT COMPANY ONLY FINANCIAL INFORMATION	PARENT COMPANY ONLY FINANCIAL INFORMATION Condensed parent company only financial statements of Nicolet Bankshares, Inc. follow. Balance Sheets December 31, (in thousands) 2018 2017 Assets Cash and due from subsidiary $ 45,279 $ 28,026 Investments 4,500 4,021 Investments in subsidiaries 384,839 379,640 Goodwill (3,266 ) (3,266 ) Other assets 53 147 Total assets $ 431,405 $ 408,568 Liabilities and Stockholders’ Equity Junior subordinated debentures $ 30,096 $ 29,616 Subordinated notes 11,957 11,921 Other liabilities 2,743 2,853 Stockholders’ equity 386,609 364,178 Total liabilities and stockholders’ equity $ 431,405 $ 408,568 Statements of Income Years Ended December 31, (in thousands) 2018 2017 2016 Interest income $ 52 $ 46 $ 58 Interest expense 2,844 2,415 1,951 Net interest expense (2,792 ) (2,369 ) (1,893 ) Dividend income from subsidiaries 40,775 32,000 35,500 Operating expense (364 ) (369 ) (202 ) Gain (loss) on investments, net 265 1,411 (500 ) Income tax benefit 305 1,329 833 Earnings before equity in undistributed income (loss) of subsidiaries 38,189 32,002 33,738 Equity in undistributed income (loss) of subsidiaries 2,847 1,148 (15,276 ) Net income attributable to Nicolet Bankshares, Inc. $ 41,036 $ 33,150 $ 18,462 Statements of Cash Flows Years Ended December 31, (in thousands) 2018 2017 2016 Cash Flows From Operating Activities: Net income attributable to Nicolet Bankshares, Inc. $ 41,036 $ 33,150 $ 18,462 Adjustments to reconcile net income to net cash provided by operating activities: Accretion of discounts 515 501 353 (Gain) loss on investments, net (265 ) (1,411 ) 500 Change in other assets and liabilities, net (25 ) (1,384 ) 395 Equity in undistributed (income) loss of subsidiaries, net of dividends (2,847 ) (1,148 ) 15,276 Net cash provided by operating activities 38,414 29,708 34,986 Cash Flows from Investing Activities: Proceeds from sale of investments 708 317 565 Purchases of investments (920 ) — — Net cash paid in business combinations — (19,287 ) (608 ) Net cash used in investing activities (212 ) (18,970 ) (43 ) Cash Flows From Financing Activities: Purchase and retirement of common stock (22,749 ) (15,007 ) (5,201 ) Proceeds from issuance of common stock, net 1,800 4,030 1,900 Capitalized issuance costs, net — — (260 ) Repayment of long-term borrowings — — (3,916 ) Redemption of preferred stock — — (12,200 ) Cash dividends paid on preferred stock — — (633 ) Net cash used in financing activities (20,949 ) (10,977 ) (20,310 ) Net increase (decrease) in cash and due from subsidiary 17,253 (239 ) 14,633 Beginning cash and due from subsidiary 28,026 28,265 13,632 Ending cash and due from subsidiary $ 45,279 $ 28,026 $ 28,265

EARNINGS PER COMMON SHARE

EARNINGS PER COMMON SHARE	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
EARNINGS PER COMMON SHARE	EARNINGS PER COMMON SHARE See Note 1 for the Company’s accounting policy on earnings per common share. Earnings per common share and related information are summarized as follows. Years Ended December 31, (in thousands, except per share data) 2018 2017 2016 Net income attributable to Nicolet Bankshares, Inc. $ 41,036 $ 33,150 $ 18,462 Less preferred stock dividends — — 633 Net income available to common shareholders $ 41,036 $ 33,150 $ 17,829 Weighted average common shares outstanding 9,640 9,440 7,158 Effect of dilutive common stock awards 316 518 356 Diluted weighted average common shares outstanding 9,956 9,958 7,514 Basic earnings per common share $ 4.26 $ 3.51 $ 2.49 Diluted earnings per common share $ 4.12 $ 3.33 $ 2.37 Options to purchase approximately 0.1 million shares outstanding for the years ended December 31, 2018 and 2017 , are excluded from the calculation of diluted earnings per common share as the effect of their exercise would have been anti-dilutive. There were no options to purchase shares that were excluded from the calculation of diluted earnings per share for the year ended December 31, 2016 .

REVENUE RECOGNITION (Notes)

REVENUE RECOGNITION (Notes)	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
REVENUE RECOGNITION	REVENUE RECOGNITION As of January 1, 2018, the Company adopted ASU 2014-09 (Topic 606) using the modified retrospective approach. The adoption of the guidance had no material impact on the measurement, timing, or recognition of revenue; however, additional disclosures have been added in accordance with the ASU. See Note 1 for additional information on this new accounting standard. Topic 606 does not apply to revenue associated with financial instruments, including revenue from loans and securities. In addition, certain noninterest income categories such as gains or losses associated with mortgage servicing rights, derivatives, and income from bank owned life insurance are not within the scope of the new guidance. The main types of revenue contracts within the scope of Topic 606 include trust services income, brokerage fee income, service charges on deposit accounts, card interchange income, and certain other noninterest income. These contracts are discussed in detail below: Trust services and brokerage fee income : A contract between the Company and its customers to provide fiduciary and / or investment administration services on trust accounts and brokerage accounts in exchange for a fee. Trust services and brokerage fee income is based upon the month-end market value of the assets under management and the applicable fee rate, which is recognized over the period the underlying trust or brokerage account is serviced (generally on a monthly basis). Such contracts are generally cancellable at any time, with the customer subject to a pro-rated fee in the month of termination. Service charges on deposit accounts : The deposit contract obligates the Company to serve as a custodian of the customer’s deposited funds and is generally terminable at will by either party. This contract permits the customer to access the funds on deposit and request additional services related to the deposit account. Service charges on deposit accounts consist of account analysis fees (net fees earned on analyzed business and public checking accounts), monthly service charges, nonsufficient fund (“NSF”) charges, and other deposit account related charges. The Company’s performance obligation for account analysis fees and monthly service charges is generally satisfied, and the related revenue recognized, over the period in which the service is provided (typically on a monthly basis); while NSF charges and other deposit account related charges are largely transactional based and the related revenue is recognized at the time the service is provided. Card interchange income : A contract between the Company, as a card-issuing bank, and its customers whereby the Company receives a transaction fee from the merchant’s bank whenever a customer uses a debit or credit card to make a purchase. The performance obligation is completed and the fees are recognized as the service is provided (i.e., when the customer uses a debit or credit card). Other noninterest income : Other noninterest income includes several items, such as wire transfer income, check cashing fees, check printing fees, safe deposit box rental fees, management fee income, and consulting fees. These fees are generally recognized at the time the service is provided.

NATURE OF BUSINESS AND SIGNIF_2

NATURE OF BUSINESS AND SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principles of Consolidation	Principles of Consolidation : The consolidated financial statements of the Company include the accounts of the Bank, Brookfield Investments, Nicolet Advisory and the JV. The JV underlies the noncontrolling interest reflected in the consolidated financial statements. The consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and conform to general practices within the banking industry. All significant intercompany accounts and transactions have been eliminated in the consolidated financial statements. Results of operations of companies purchased, if any, are included from the date of acquisition.
Operating Segment	Operating Segment: The consolidated income of the Company is derived principally from the Bank, which conducts lending (primarily commercial-based loans, as well as residential and consumer loans) and deposit gathering (including other banking- and deposit-related products and services, such as ATMs, safe deposit boxes, check-cashing, wires, and debit cards) to businesses, consumers and governmental units principally in its trade area of northeastern and central Wisconsin, and Menominee, Michigan, trust services, brokerage services (delivered through the Bank and Nicolet Advisory), and the support to deliver, fund and manage all such banking and wealth management services to its customer base. The contribution of the JV, Brookfield Investments and Nicolet Advisory were not significant to the consolidated balance sheet or net income for 2018 , 2017 , or 2016 . While the chief operating decision makers monitor the revenue streams of the various products and services, and evaluate costs, balance sheet positions and quality, all such products, services and activities are directly or indirectly related to the business of community banking, with no regular, formal or material segment delineations. Operations are managed and financial performance is evaluated on a company-wide basis, and accordingly, all the financial service operations are considered by management to be aggregated in one reportable operating segment.
Use of Estimates	Use of Estimates : Preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying disclosures. These estimates are based on management’s best knowledge of current events and actions the Company may undertake in the future. Estimates are used in accounting for, among other items, the allowance for loan losses, valuation of loans in acquisition transactions, useful lives for depreciation and amortization, fair value of financial instruments, other-than-temporary impairment calculations, valuation of deferred tax assets, uncertain income tax positions, and contingencies. Estimates that are particularly susceptible to significant change for the Company include the determination of the allowance for loan losses, determination and assessment of deferred tax assets and liabilities, and the valuation of loans acquired in acquisition transactions; therefore, these are critical accounting policies. Factors that may cause sensitivity to the aforementioned estimates include but are not limited to: external market factors such as market interest rates and employment rates, changes to operating policies and procedures, changes in applicable banking or tax regulations, and changes to deferred tax estimates. Actual results may ultimately differ from estimates, although management does not generally believe such differences would materially affect the consolidated financial statements in any individual reporting period presented.
Business Combinations	Business Combinations: The Company accounts for business combinations under the acquisition method of accounting in accordance with Accounting Standards Codification (“ASC”) 805, Business Combinations (“ASC 805”). The Company recognizes the full fair value of the assets acquired and liabilities assumed and immediately expenses transaction costs. There is no separate recognition of the acquired allowance for loan losses on the acquirer’s balance sheet as credit related factors are incorporated directly into the fair value of the net tangible and intangible assets acquired. If the amount of consideration exceeds the fair value of assets purchased less the fair value of liabilities assumed, goodwill is recorded. Alternatively, if the amount by which the fair value of assets purchased exceeds the fair value of liabilities assumed and consideration paid, a gain (“bargain purchase gain”) is recorded. Fair values are subject to refinement for up to one year after the closing date of an acquisition as information relative to closing date fair values becomes available. Results of operations of the acquired business are included in the statements of income from the effective date of the acquisition. Additional information regarding recent acquisitions is provided in Note 2 .
Cash and Cash Equivalents	Cash and Cash Equivalents : For purposes of the consolidated statements of cash flows, cash and cash equivalents include cash and due from banks, interest-earning deposits in other banks with original maturities of less than 90 days, if any, and federal funds sold. The Bank maintains amounts in due from banks which, at times, may exceed federally insured limits. Management monitors these correspondent relationships. The Bank has not experienced any losses in such accounts. The Bank may have restrictions on cash and due from banks as it is required to maintain certain vault cash and reserve balances with the Federal Reserve Bank to meet specific reserve requirements.
Securities Available for Sale	Securities Available for Sale : Securities classified as AFS are those securities that the Company intends to hold for an indefinite period of time, but not necessarily to maturity, and includes U.S. government agency securities; state, county and municipal securities; mortgage-backed securities; and corporate debt securities. Effective January 1, 2018, the Company adopted a new accounting standard, which requires equity securities with readily determinable fair values to be measured at fair value with changes in the fair value recognized through net income (see Recent Accounting Pronouncements Adopted within Note 1 for the impact of this new accounting guidance). Such securities are no longer reflected as securities AFS, and are now reflected within other investments on the consolidated balance sheets. Prior periods have not been restated for the impact of this accounting change. Thus, at December 31, 2018, the current fair value of $2.7 million for equity securities is included in other investments while at December 31, 2017, the fair value of $2.6 million for equity securities was reflected in securities AFS. Any decision to sell a security classified as AFS would be based on various factors, including significant movements in interest rates, changes in the maturity mix of the Company’s assets and liabilities, liquidity needs, regulatory capital considerations, and other similar factors. Securities classified as AFS are carried at fair value, with unrealized gains or losses, net of related deferred income taxes, reported as increases or decreases in accumulated other comprehensive income. Realized gains or losses on sales of securities AFS (using the specific identification method) and declines in value judged to be other-than-temporary are included in the consolidated statements of income under asset gains (losses), net. Premiums and discounts are amortized or accreted into interest income over the life of the related securities using the effective interest method. See Note 3 for additional disclosures on AFS securities. Management evaluates securities for other-than-temporary impairment on at least an annual basis. A decline in the market value of any investment below amortized cost that is deemed other-than-temporary is charged to earnings for the decline in value deemed to be credit related and a new cost basis in the security is established. The decline in value attributed to non-credit related factors considered temporary in nature is recognized in other comprehensive income. In evaluating other-than-temporary impairment, management considers the length of time and extent to which the fair value has been less than cost, and the financial condition and near-term prospects of the issuer for a period sufficient to allow for any anticipated recovery in fair value in the near term.
Other Investments	Other Investments : Other investments includes equity securities with readily determinable fair values, "restricted" equity securities, and private company securities. As noted under Securities Available for Sale above, at December 31, 2018, other investments includes $2.7 million of equity securities with readily determinable fair values. As a member of the Federal Reserve Bank System, Federal Agricultural Mortgage Corporation, and the Federal Home Loan Bank (“FHLB”) System, the Bank is required to maintain an investment in the capital stock of these entities. These equity securities are “restricted” in that they can only be sold back to the respective institutions or another member institution at par. Therefore, they are less liquid than other exchange traded equity securities. As no ready market exists for these stocks, and they have no quoted market value, these investments are carried at cost. Also included are investments in other private companies that do not have quoted market prices, which are carried at cost less other-than-temporary impairment charges, if any. Management’s evaluation of these other investments for impairment includes consideration of the financial condition and other available relevant information of the issuer.
Loans Held for Sale	Loans Held for Sale : Loans originated and intended for sale in the secondary market are carried at the lower of cost or estimated fair value as determined on an aggregate basis and generally consist of current production of certain fixed-rate residential first mortgages. The amount by which cost exceeds market value is recorded as a valuation allowance and charged to earnings. Changes, if any, in the valuation allowance are also included in earnings in the period in which the change occurs. As of December 31, 2018 and 2017 , no valuation allowance was necessary. Loans held for sale may be sold servicing retained or servicing released, and are generally sold without recourse. The carrying value of mortgage loans sold with servicing retained is reduced by the amount allocated to the servicing right at the time of sale. Gains and losses on sales of mortgage loans held for sale are included in earnings in mortgage income, net.
Credit-Related Financial Instruments	Credit-Related Financial Instruments : In the ordinary course of business the Company has entered into financial instruments consisting of commitments to extend credit, financial standby letters of credit, and performance standby letters of credit. Financial standby letters of credit are issued specifically to facilitate commerce and typically result in the commitment being drawn on when the underlying transaction is consummated between the customer and the third party, while performance standby letters of credit generally are contingent upon the failure of the customer to perform according to the terms of the underlying contract with the third party. Such financial instruments are recorded in the consolidated financial statements when they are funded. See Note 14 for additional information and disclosures on credit-related financial instruments.
Transfers of Financial Assets	Transfers of Financial Assets : Transfers of financial assets, primarily in loan participation activities, are accounted for as sales only when control over the assets has been surrendered. Control over transferred assets is deemed to be surrendered when (1) the assets have been isolated from the Company, (2) the transferee obtains the right (free of conditions that constrain it from taking advantage of the right) to pledge or exchange the transferred assets, and (3) the Company does not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity or the ability to unilaterally cause the holder to return assets.
Premises and Equipment	Premises and Equipment : Premises and equipment are stated at cost less accumulated depreciation and amortization. Premises and equipment from acquisitions were recorded at estimated fair value on the respective dates of acquisition. Depreciation is computed on straight-line and accelerated methods over the estimated useful lives of the related assets. Leasehold improvements are amortized on the straight-line method over the shorter of the estimated useful lives of the improvements or the terms of the related leases. Maintenance and repairs are expensed as incurred. See Note 5 for additional information on premises and equipment. Estimated useful lives of new premises and equipment generally range as follows: Building and improvements 25 – 40 years Leasehold improvements 5 – 15 years Furniture and equipment 3 – 10 years
Other Real Estate Owned ("OREO")	Other Real Estate Owned (“OREO”) : OREO acquired through partial or total satisfaction of loans or bank facilities no longer in use are carried at fair value less estimated costs to sell. Any write-down in the carrying value of loans or vacated bank premises at the time of transfer to OREO is charged to the ALLL or to write-down of assets, respectively. OREO properties acquired in conjunction with the acquisition transactions were recorded at fair value on the date of acquisition. Any subsequent write-downs to reflect current fair value, as well as gains or losses on disposition and revenues and expenses incurred to hold and maintain such properties, are treated as period costs. See Note 7 for additional information on OREO.
Goodwill and Other Intangibles	Goodwill and Other Intangibles : Goodwill represents the excess of the purchase price over the fair value of the net identifiable assets acquired. Goodwill is not amortized but is subject to impairment tests on at least an annual basis. Other intangibles include core deposit intangibles (which represent the value of acquired customer core deposit bases) and customer list intangibles. The core deposit intangibles have an estimated finite life, are amortized on an accelerated basis over a 10 -year period, and are subject to periodic impairment evaluation. The customer list intangibles have finite lives and are amortized on a straight-line basis to expense over their initial weighted average life of approximately 12 years as of acquisition. See Note 6 for additional information on goodwill and other intangibles. Management periodically reviews the carrying value of its intangible assets to determine if any impairment has occurred, in which case an impairment charge would be recorded as an expense in the period of impairment, or whether changes in circumstances have occurred that would require a revision to the remaining useful life which would impact expense prospectively. In making such determination, management evaluates whether there are any adverse qualitative factors indicating that an impairment may exist, as well as the performance, on an undiscounted basis, of the underlying operations or assets which give rise to the intangible.
Mortgage Servicing Rights ("MSRs")	Mortgage Servicing Rights (“MSRs”): If the Company sells originated residential mortgages into the secondary market and retains the right to service the loans sold, then a mortgage servicing right asset (liability) is capitalized upon sale with the offsetting effect recorded as a gain (loss) on sale of loans in earnings (included in mortgage income, net), representing the then-current estimated fair value of future net cash flows expected to be realized for performing the servicing activities. MSRs when purchased (including MSRs purchased in acquisitions) are initially recorded at their then-estimated fair value. As the Company has not elected to measure any class of servicing assets under the fair value method, the Company utilizes the amortization method. MSRs are amortized in proportion to and over the period of estimated net servicing income, with the amortization charged to earnings (included in mortgage income, net). MSRs are carried at the lower of initial capitalized amount, net of accumulated amortization, or estimated fair value, and are included in other assets in the consolidated balance sheets. Loan servicing fee income for servicing loans is typically based on a contractual percentage of the outstanding principal and is recorded as income when earned (included in mortgage income, net with less material late fees and ancillary fees related to loan servicing). The Company periodically evaluates its MSRs for impairment. At each reporting date impairment is assessed based on estimated fair value using estimated prepayment speeds of the underlying mortgage loans serviced and stratifications based on the risk characteristics of the underlying loans (predominantly loan type and note interest rate). The value of MSRs is adversely affected when mortgage interest rates decline and mortgage loan prepayments increase. A valuation allowance is established through a charge to earnings (included in mortgage income, net) to the extent the amortized cost of the MSRs exceeds the estimated fair value by stratification. If it is later determined that all or a portion of the temporary impairment no longer exists for a stratification, the valuation is reduced through a recovery to earnings, though not beyond the net amortized cost carried. An other-than-temporary impairment (i.e., recoverability is considered remote when considering interest rates and loan payoff activity) is recognized as a write-down of the MSRs and the related valuation allowance (to the extent a valuation allowance is available) and then against earnings. A direct write-down permanently reduces the carrying value of the MSRs and valuation allowance, precluding subsequent recoveries. No valuation allowance or impairment charge was recorded for 2018 or 2017 . See Note 6 for additional information on MSRs.
Bank-owned Life Insurance ("BOLI")	Bank-owned Life Insurance (“BOLI”): The Company owns BOLI on certain executives and employees. BOLI balances are recorded at their cash surrender values. Changes in the cash surrender values and death proceeds exceeding carrying values are included in noninterest income.
Short-term Borrowings	Short-term Borrowings : Short-term borrowings consist primarily of overnight Federal funds purchased and securities sold under agreements to repurchase (“repos”), or other short-term borrowing arrangements with an original maturity of one year or less. Repos are with commercial deposit customers, and are treated as financing activities carried at the amounts that will be subsequently repurchased as specified in the respective agreements. Repos generally mature within one to four days from the transaction date. The Company may be required to provide additional collateral based on the fair value of the underlying securities.
Stock-based Compensation Plans	Stock-based Compensation Plans: Share-based payments to employees, including grants of restricted stock or stock options, are valued at fair value of the award on the date of grant and expensed on a straight-line basis as compensation expense over the applicable vesting period. A Black-Scholes model is utilized to estimate the fair value of stock options and the market price of the Company’s stock at the date of grant is used to estimate the fair value of restricted stock awards. See Note 11 for additional information on stock-based compensation.
Income Taxes	Income Taxes : The Company files a consolidated federal income tax return and a combined state income tax return (both of which include the Company and its wholly owned subsidiaries). Accordingly, amounts equal to tax benefits of those companies having taxable federal losses or credits are reimbursed by the companies that incur federal tax liabilities. Amounts provided for income tax expense are based on income reported for financial statement purposes and do not necessarily represent amounts currently payable under tax laws. Deferred income tax assets and liabilities are computed annually for differences between the financial statement and tax bases of assets and liabilities that will result in taxable or deductible amounts in the future based on enacted tax rates applicable to the periods in which the differences are expected to affect taxable income. As changes in tax laws or rates are enacted, deferred tax assets and liabilities are adjusted through income tax expense. Valuation allowances are established when it is more likely than not that a portion of the full amount of the deferred tax asset will not be realized. In assessing the ability to realize deferred tax assets, management considers the scheduled reversal of deferred tax liabilities, projected future taxable income and tax planning strategies. At acquisition, deferred taxes were evaluated in respect to the acquired assets and assumed liabilities (including the acquired net operating losses), and a net deferred tax asset was recorded. Certain limitations within the provisions of the tax code are placed on the amount of net operating losses which can be utilized as part of acquisition accounting rules and were incorporated into the calculation of the deferred tax asset. In addition, a portion of the fair market value discounts on PCI loans which resolved in the first twelve months after the acquisition were disallowed under provisions of the tax code. The Company may also recognize a liability for unrecognized tax benefits from uncertainty in income tax positions. Unrecognized tax benefits represent the differences between a tax position taken or expected to be taken in a tax return and the benefit recognized and measured in the consolidated financial statements. At December 31, 2018 , the Company determined it had no significant uncertainty in income tax positions. Interest and penalties related to unrecognized tax benefits are classified as income tax expense. See Note 13 for additional information on income taxes.
Earnings per Common Share	Earnings per Common Share : Basic earnings per common share are calculated by dividing net income available to common shareholders by the weighted average number of common shares outstanding during the period. Diluted earnings per common share are calculated by dividing net income available to common shareholders by the weighted average number of common shares adjusted for the dilutive effect of outstanding common stock awards, if any. See Note 20 for additional information on earnings per common share.
Treasury Stock	Treasury Stock : Treasury stock is accounted for at cost on a first-in-first-out basis. It is the Company’s general practice to cancel treasury stock shares in the same quarter as purchased, and thus, not carry a treasury stock balance.
Comprehensive Income	Comprehensive Income : Accounting principles generally require that recognized revenue, expenses, gains and losses be included in net income. Certain changes in assets and liabilities, such as unrealized gains and losses on securities AFS, bypass the statement of income and instead are reported in accumulated other comprehensive income, as a separate component of the equity section of the balance sheet. Realized gains or losses are reclassified to current period income. Changes in these items, along with net income, are components of comprehensive income. The Company presents comprehensive income in a separate consolidated statement of comprehensive income.
Reclassifications	Reclassifications : Certain amounts in the 2017 and 2016 consolidated financial statements have been reclassified to conform to the 2018 presentation.
Recent Accounting Pronouncements Adopted	Recent Accounting Pronouncements Adopted : In May 2017, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2017-09, Compensation – Stock Compensation (Topic 718) . ASU 2017-09 applies to entities that change the terms or conditions of a share-based payment award to provide clarity and reduce diversity in practice as well as cost and complexity when applying the guidance in Topic 718 to the modification to the terms and conditions of a share-based payment award. The updated guidance was effective for interim and annual reporting periods beginning after December 15, 2017. The Company adopted the updated guidance effective January 1, 2018 with no material impact on its consolidated financial statements. In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business , to clarify the definition of a business to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets versus businesses. The update narrows the definition of a business by adding three principal clarifications: (1) if substantially all the fair value of the gross assets in the asset group is concentrated in either a single identifiable asset or group of similar identifiable assets the transaction does not involve a business, (2) if the asset group does not include a minimum of an input and a substantive process, it does not represent a business, and (3) if the integrated set of activities (including its inputs and processes) does not create, or have the ability to create, goods or services to customers, investment income (e.g., dividends or interest) or other revenue, it is not a business. The overall intention is to provide consistency in applying the guidance and make the definition of a business more operable. This update was effective for fiscal years beginning after December 15, 2017, incluing interim periods within those fiscal years and should be applied prospectively. The Company adopted the updated guidance effective January 1, 2018 with no material impact on its consolidated financial statements. In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash to provide guidance on the presentation of restricted cash or restricted cash equivalents in the statement of cash flows to reduce diversity in practice. The amendment requires that a statement of cash flow explain the change during the period in the total cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash or restricted cash equivalents should be included in cash and cash equivalents when reconciling the beginning and end of period total amounts shown on the statement of cash flow. This amendment was effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years and should be applied retrospectively to each period presented. The Company adopted the updated guidance effective January 1, 2018 with no material impact on its consolidated financial statements. See the consolidated statements of cash flows for additional disclosures related to this ASU. In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts to address diversity in how certain cash receipts and cash payments are presented and classified in the statement of cash flows. The amendments provide guidance on specific cash flow issues, including: debt prepayment or debt extinguishment costs, contingent consideration payments made after a business combination, proceeds from the settlement of insurance claims, proceeds from the settlement of Corporate-Owned Life Insurance Policies, including Bank-Owned Life Insurance Policies, and distributions received from equity method investees. The amendments were effective for public business entities for fiscal years beginning after December 31, 2017, and interim periods within those fiscal years. The Company adopted the updated guidance effective January 1, 2018 with no material impact on its consolidated financial statements. In January 2016, the FASB issued ASU 2016-01, Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities , to address certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. This amendment supersedes the guidance to classify equity securities with readily determinable fair values into different categories, requires equity securities to be measured at fair value with changes in the fair value recognized through net income, and simplifies the impairment assessment of equity investments without readily determinable fair values. The amendment also requires public business entities that are required to disclose the fair value of financial instruments measured at amortized cost on the balance sheet to measure that fair value using the exit price notion. The amendment requires separate presentation of financial assets and financial liabilities by measurement category and form of financial asset on the balance sheet or in the accompanying notes to the financial statements. This amendment was effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Entities were required to apply the amendment by means of a cumulative-effect adjustment as of the beginning of the fiscal year of adoption, with the exception of the amendment related to equity securities without readily determinable fair values, which should be applied prospectively to equity investments that exist as of the date of adoption. The Company adopted the updated guidance effective January 1, 2018 and recognized a cumulative effect adjustment at adoption of approximately $0.9 million for the after tax impact of the unrealized gain on equity securities. See the consolidated statement of stockholders’ equity and Note 3 for additional disclosures related to this ASU. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) , with several subsequent updates. The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods and services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods and services. Topic 606 provides a five-step model to apply to revenue recognition, consisting of the following: (1) identify the contract; (2) identify the performance obligation in the contract; (3) determine the transaction price; (4) allocate the transaction price to the performance obligations; and (5) recognize revenue when or as the performance obligation is satisfied. The guidance was effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. The Company adopted the updated guidance using the modified retrospective approach effective January 1, 2018, with no material impact on its consolidated financial statements. See Note 21 for the new disclosures related to Topic 606.
Originated Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Allowance for Loan Losses ("ALLL")	Loans and Allowance for Loan Losses (“ALLL”) – Originated Loans : Loans that management has the intent and ability to hold for the foreseeable future or until maturity or payoff are carried at their principal amount outstanding, net of deferred loan fees and costs. Interest income is accrued on the unpaid principal balance using the simple interest method. The accrual of interest income on loans is discontinued when, in the opinion of management, there is reasonable doubt as to the borrower’s ability to meet payment of interest or principal when due. Loans are generally placed on nonaccrual status when contractually past due 90 days or more as to interest or principal, though may be placed in such status earlier based on the circumstances. Loans past due 90 days or more may continue on accrual only when they are well secured and/or in process of collection or renewal. When interest accrual is discontinued, all previously accrued but uncollected interest is reversed against current period interest income. Except in very limited circumstances, cash collections on nonaccrual loans are credited to the loan receivable balance and no interest income is recognized on those loans until the principal balance is paid in full. Accrual of interest may be resumed when the customer is current on all principal and interest payments and has been paying on a timely basis for a sustained period of time. See Note 4 for additional information and disclosures on originated loans. Management considers a loan to be impaired when it is probable the Company will be unable to collect all contractual principal and interest payments due in accordance with the terms of the loan agreement. For determining the appropriateness of the ALLL, management defines impaired loans as nonaccrual credit relationships over $250,000 , all loans determined to be troubled debt restructurings, plus additional loans with impairment risk characteristics. At the time an individual loan goes into nonaccrual status, management evaluates the loan for impairment and possible charge-off regardless of loan size. Typically, impairment amounts for loans under the scope criteria are charged off when the impairment amount is determined. The ALLL represents management’s estimate of probable and inherent credit losses in the Company’s loan portfolio at the balance sheet date. In general, estimating the amount of the ALLL is a function of a number of factors, including but not limited to changes in the loan portfolio, net charge-offs, trends in past due and impaired loans, and the level of potential problem loans, all of which may be susceptible to significant change. Actual credit losses, net of recoveries, are deducted from the ALLL. Loans are charged off when management believes that the collectability of the principal is unlikely. Subsequent recoveries, if any, are credited to the ALLL. A provision for loan losses, which is a charge against income, is recorded to bring the ALLL to a level that, in management’s judgment, is appropriate to absorb probable losses in the loan portfolio. The allocation methodology applied by the Company is designed to assess the overall appropriateness of the ALLL and includes allocations for specifically identified impaired loans and loss factors for all remaining loans, with a component primarily based on historical loss rates and another component primarily based on other qualitative factors. Impaired loans are individually assessed and are measured based on the present value of expected future cash flows discounted at the loan’s effective interest rate or, as a practical expedient, at the loan’s observable market price or the fair value of the collateral if the loan is collateral dependent. Loans that are determined not to be impaired are collectively evaluated for impairment, stratified by type and allocated loss ranges based on the Company’s actual historical loss ratios for each strata, and adjustments are also provided for certain current environmental and qualitative factors. An internal loan review function rates loans using a grading system based on nine different categories. Loans with grades of seven or higher (“classified loans”) represent loans with a greater risk of loss and may be assigned allocations for loss based on specific review of the weaknesses observed in the individual credits if classified as impaired. Classified loans are constantly monitored by the loan review function to ensure early identification of any deterioration. Allocations to the ALLL may be made for specific loans but the entire ALLL is available for any loan that, in management’s judgment, should be charged-off or for which an actual loss is realized. The allowance analysis is reviewed by the Board on a quarterly basis in compliance with internal and regulatory requirements.
Acquired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Allowance for Loan Losses ("ALLL")	Loans and ALLL – Acquired Loans: The loans purchased in acquisition transactions are acquired loans. Acquired loans are recorded at their estimated fair value at the acquisition date, and are initially classified as either purchase credit impaired (“PCI”) loans (i.e., loans that reflect credit deterioration since origination and it is probable at acquisition that the Company will be unable to collect all contractually required payments) or purchased non-impaired loans (i.e., “performing acquired loans”). See Note 4 for additional information and disclosures on acquired loans. PCI loans are accounted for under the accounting guidance for loans and debt securities acquired with deteriorated credit quality, found in Financial Accounting Standards Board (“FASB”) ASC Topic 310-30, Receivables—Loans and Debt Securities Acquired with Deteriorated Credit Quality . The Company estimates the amount and timing of expected principal, interest and other cash flows for each loan or pool of loans meeting the criteria above, and determines the excess of the loan’s scheduled contractual principal and contractual interest payments over all cash flows expected to be collected at acquisition as an amount that should not be accreted. These credit discounts (“nonaccretable marks”) are included in the determination of the initial fair value for acquired loans; therefore, an allowance for loan losses is not recorded at the acquisition date. Differences between the estimated fair values and expected cash flows of acquired loans at the acquisition date that are not credit-based (“accretable marks”) are subsequently accreted to interest income over the estimated life of the loans using a method that approximates a level yield if the timing and amount of the future cash flows is reasonably estimable. Subsequent to the acquisition date for PCI loans, increases in cash flows over those expected at the acquisition date result in a move of the discount from nonaccretable to accretable. Decreases in expected cash flows after the acquisition date are recognized through the provision for loan losses. All fair value discounts initially recorded on PCI loans were deemed to be credit related. Performing acquired loans are accounted for under FASB ASC Topic 310-20, Receivables—Nonrefundable Fees and Other Costs . Performance of certain loans may be monitored, and based on management’s assessment of the cash flows and other facts available, portions of the accretable difference may be delayed or suspended if management deems appropriate. The Company’s policy for determining when to discontinue accruing interest on performing acquired loans and the subsequent accounting for such loans is essentially the same as the policy for originated loans described above. An ALLL is calculated using a methodology similar to that described for originated loans. Performing acquired loans are subsequently evaluated for any required allowance at each reporting date. Such required allowance for each loan pool is compared to the remaining fair value discount for that pool. If greater, the excess is recognized as an addition to the allowance through a provision for loan losses charge. If less than the discount, no additional allowance is recorded. Charge-offs and losses first reduce any remaining fair value discount for the loan pool and once the discount is depleted, losses are applied against the allowance established for that pool. For PCI loans after acquisition, cash flows expected to be collected are recast for each loan periodically as determined appropriate by management. If the present value of expected cash flows for a loan is less than its carrying value, impairment is reflected by an increase in the ALLL and a charge to the provision for loan losses. If the present value of the expected cash flows for a loan is greater than its carrying value, any previously established ALLL is reversed and any remaining difference increases the accretable yield which will be taken into income over the remaining life of the loan. Loans which were considered troubled debt restructurings prior to the acquisition transaction are not required to be classified as troubled debt restructurings in the Company’s consolidated financial statements unless or until such loans would subsequently meet criteria to be classified as such, since acquired loans were recorded at their estimated fair values at the time of the acquisition.

NATURE OF BUSINESS AND SIGNIF_3

NATURE OF BUSINESS AND SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Schedule of estimated useful lives of premises and equipment	Building and improvements 25 – 40 years Leasehold improvements 5 – 15 years Furniture and equipment 3 – 10 years

ACQUISITIONS (Tables)

ACQUISITIONS (Tables)	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Schedule of fair value of the assets acquired and liabilities assumed	The Company accounted for the transaction under the acquisition method of accounting, and thus, the financial position and results of operations of Baylake prior to the consummation date were not included in the accompanying consolidated financial statements. The fair value of the assets acquired and liabilities assumed on April 29, 2016 was as follows. (in millions) As recorded by Fair Value As Recorded Cash, cash equivalents and securities available for sale $ 262 $ 1 $ 263 Loans 710 (19 ) 691 Other real estate owned 3 (2 ) 1 Core deposit intangible 1 16 17 Fixed assets and other assets 71 (8 ) 63 Total assets acquired $ 1,047 $ (12 ) $ 1,035 Deposits $ 822 $ — $ 822 Junior subordinated debentures, borrowings and other liabilities 116 (1 ) 115 Total liabilities acquired $ 938 $ (1 ) $ 937 Excess of assets acquired over liabilities acquired $ 109 $ (11 ) $ 98 Less: purchase price 164 Goodwill $ 66
Schedule of unaudited pro forma information of future results of operations	These unaudited pro forma results are presented for illustrative purposes and are not intended to represent or be indicative of the actual results of operations of the combined company that would have been achieved had the acquisition occurred at the beginning of each period presented, nor are they intended to represent or be indicative of future results of operations. Year Ended December 31, 2016 (in thousands, except per share data) Total revenues, net of interest expense $ 110,788 Net income 23,263 Diluted earnings per share 2.55

SECURITIES AVAILABLE FOR SALE (

SECURITIES AVAILABLE FOR SALE (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Securities, Available-for-sale [Abstract]
Debt Securities, Trading, and Equity Securities, FV-NI [Table Text Block]	Amortized cost and fair value of securities available for sale are summarized as follows. December 31, 2018 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. government agency securities $ 22,467 $ — $ 818 $ 21,649 State, county and municipals 163,702 76 3,252 160,526 Mortgage-backed securities 134,350 328 3,034 131,644 Corporate debt securities 87,352 66 1,093 86,325 $ 407,871 $ 470 $ 8,197 $ 400,144 December 31, 2017 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. government agency securities $ 26,586 $ — $ 377 $ 26,209 State, county and municipals 186,128 180 2,264 184,044 Mortgage-backed securities 157,705 160 2,333 155,532 Corporate debt securities 36,387 449 39 36,797 Equity securities * 1,287 1,284 — 2,571 $ 408,093 $ 2,073 $ 5,013 $ 405,153 * Effective January 1, 2018, the Company adopted ASU 2016-01, which requires equity securities with readily determinable fair values to be measured at fair value with changes in the fair value recognized through net income. These equity securities are no longer reflected in securities AFS and are now reflected within other investments. As a result of this accounting change, the Company recognized a cumulative-effect adjustment at adoption from accumulated other comprehensive income to retained earnings of approximately $0.9 million in the consolidated statements of changes in stockholders' equity for the net of tax impact of the unrealized gain on equity securities as of the date of adoption and recognized a gain of approximately $77,000 for the year ended December 31, 2018 , in the consolidated statements of income for the change in fair value of equity securities since adoption. In addition, the approximately $2.7 million current fair value of equity securities is now reflected within other investments on the consolidated balance sheets rather than as securities AFS. Prior periods have not been restated for the impact of this accounting change. See Note 1 for additional information on this new accounting standard.
Schedule of amortized costs and fair values of securities AFS	Amortized cost and fair value of securities available for sale are summarized as follows. December 31, 2018 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. government agency securities $ 22,467 $ — $ 818 $ 21,649 State, county and municipals 163,702 76 3,252 160,526 Mortgage-backed securities 134,350 328 3,034 131,644 Corporate debt securities 87,352 66 1,093 86,325 $ 407,871 $ 470 $ 8,197 $ 400,144 December 31, 2017 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. government agency securities $ 26,586 $ — $ 377 $ 26,209 State, county and municipals 186,128 180 2,264 184,044 Mortgage-backed securities 157,705 160 2,333 155,532 Corporate debt securities 36,387 449 39 36,797 Equity securities * 1,287 1,284 — 2,571 $ 408,093 $ 2,073 $ 5,013 $ 405,153 * Effective January 1, 2018, the Company adopted ASU 2016-01, which requires equity securities with readily determinable fair values to be measured at fair value with changes in the fair value recognized through net income. These equity securities are no longer reflected in securities AFS and are now reflected within other investments. As a result of this accounting change, the Company recognized a cumulative-effect adjustment at adoption from accumulated other comprehensive income to retained earnings of approximately $0.9 million in the consolidated statements of changes in stockholders' equity for the net of tax impact of the unrealized gain on equity securities as of the date of adoption and recognized a gain of approximately $77,000 for the year ended December 31, 2018 , in the consolidated statements of income for the change in fair value of equity securities since adoption. In addition, the approximately $2.7 million current fair value of equity securities is now reflected within other investments on the consolidated balance sheets rather than as securities AFS. Prior periods have not been restated for the impact of this accounting change. See Note 1 for additional information on this new accounting standard.
Schedule of amortized cost and fair value classified by contractual maturities	The amortized cost and fair value of securities AFS by contractual maturity are shown below. Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties; as this is particularly inherent in mortgage-backed securities, these securities are not included in the maturity categories below. See Note 18 for additional information on the Company’s fair value measurements. December 31, 2018 (in thousands) Amortized Cost Fair Value Due in less than one year $ 17,643 $ 17,624 Due in one year through five years 168,090 164,969 Due after five years through ten years 80,819 78,904 Due after ten years 6,969 7,003 273,521 268,500 Mortgage-backed securities 134,350 131,644 Securities AFS $ 407,871 $ 400,144
Schedule of Proceeds from sales of securities AFS	Proceeds from sales of securities AFS is summarized as follows. Years Ended December 31, (in thousands) 2018 2017 2016 Gross gains $ — $ 1,227 $ 91 Gross losses (212 ) (7 ) (13 ) Gains (losses) on sales of securities AFS, net $ (212 ) $ 1,220 $ 78 Proceeds from sales of securities AFS $ 5,280 $ 10,798 $ 31,442
Gain (Loss) on Securities	The following table presents gross unrealized losses and the related estimated fair value of investment securities available for sale, aggregated by investment category and the length of time the individual securities have been in a continuous unrealized loss position. December 31, 2018 Less than 12 months 12 months or more Total (in thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Number of Securities U.S. government agency securities $ — $ — $ 21,649 $ 818 $ 21,649 $ 818 3 State, county and municipals 16,136 98 130,975 3,154 147,111 3,252 440 Mortgage-backed securities 20,568 132 89,189 2,902 109,757 3,034 204 Corporate debt securities 51,592 677 9,757 416 61,349 1,093 33 $ 88,296 $ 907 $ 251,570 $ 7,290 $ 339,866 $ 8,197 680 December 31, 2017 Less than 12 months 12 months or more Total (in thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Number of Securities U.S. government agency securities $ 26,209 $ 377 $ — $ — $ 26,209 $ 377 2 State, county and municipals 110,157 1,097 49,326 1,167 159,483 2,264 465 Mortgage-backed securities 72,210 735 65,537 1,598 137,747 2,333 215 Corporate debt securities 10,172 39 — — 10,172 39 5 $ 218,748 $ 2,248 $ 114,863 $ 2,765 $ 333,611 $ 5,013 687

LOANS, ALLOWANCE FOR LOAN LOS_2

LOANS, ALLOWANCE FOR LOAN LOSSES, AND CREDIT QUALITY (Tables)	12 Months Ended
	Dec. 31, 2018
Receivables [Abstract]
Schedule of loan composition and further breakdown summarized by originated and acquired	As a further breakdown, loans are summarized by originated and acquired as follows. December 31, 2018 December 31, 2017 (in thousands) Originated Amount % of Total Acquired Amount % of Total Originated Amount % of Total Acquired Amount % of Total Commercial & industrial $ 568,100 38 % $ 116,820 17 % $ 488,600 39 % $ 148,737 17 % Owner-occupied CRE 283,531 19 157,822 23 237,548 19 192,495 23 AG production 11,113 1 24,512 4 11,102 1 24,353 3 AG real estate 31,374 2 22,070 3 27,831 2 23,947 3 CRE investment 171,087 12 172,565 25 113,862 9 200,601 24 Construction & land development 66,478 4 14,121 2 56,061 5 33,599 4 Residential construction 30,926 2 — — 33,615 3 3,380 — Residential first mortgage 220,368 15 137,473 20 191,186 15 172,166 20 Residential junior mortgage 78,379 5 32,949 5 65,643 5 40,384 5 Retail & other 23,809 2 2,684 1 18,254 2 4,561 1 Loans 1,485,165 100 % 681,016 100 % 1,243,702 100 % 844,223 100 % Less ALLL 11,448 1,705 10,542 2,111 Loans, net $ 1,473,717 $ 679,311 $ 1,233,160 $ 842,112 ALLL to loans 0.77 % 0.25 % 0.85 % 0.25 % The loan composition is summarized as follows. December 31, 2018 December 31, 2017 (in thousands) Amount % of Total Amount % of Total Commercial & industrial $ 684,920 32 % $ 637,337 31 % Owner-occupied commercial real estate (“CRE”) 441,353 20 430,043 21 Agricultural (“AG”) production 35,625 2 35,455 2 AG real estate 53,444 2 51,778 2 CRE investment 343,652 16 314,463 15 Construction & land development 80,599 4 89,660 4 Residential construction 30,926 1 36,995 2 Residential first mortgage 357,841 17 363,352 17 Residential junior mortgage 111,328 5 106,027 5 Retail & other 26,493 1 22,815 1 Loans 2,166,181 100 % 2,087,925 100 % Less ALLL 13,153 12,653 Loans, net $ 2,153,028 $ 2,075,272 ALLL to loans 0.61 % 0.61 %
Schedule Of Roll Forward Of Allowance For Loan Losses Table	A roll forward of the allowance for loan losses is summarized as follows. Years Ended December 31, (in thousands) 2018 2017 2016 Beginning balance $ 12,653 $ 11,820 $ 10,307 Provision for loan losses 1,600 2,325 1,800 Charge-offs (1,213 ) (1,604 ) (584 ) Recoveries 113 112 297 Net charge-offs (1,100 ) (1,492 ) (287 ) Ending balance $ 13,153 $ 12,653 $ 11,820
Schedule of changes in ALLL by portfolio segment and further breakdown summarized by originated and acquired	The following tables present the balance and activity in the ALLL by portfolio segment and the recorded investment in loans by portfolio segment for the year ended December 31, 2018 . TOTAL – Year Ended December 31, 2018 (in thousands) Commercial & industrial Owner- occupied CRE AG production AG real estate CRE investment Construction & land development Residential construction Residential first mortgage Residential junior mortgage Retail & other Total ALLL: Beginning balance $ 4,934 $ 2,607 $ 129 $ 296 $ 1,388 $ 726 $ 251 $ 1,609 $ 488 $ 225 $ 12,653 Provision 1,107 300 (8 ) 5 119 (216 ) (40 ) 117 (51 ) 267 1,600 Charge-offs (813 ) (74 ) — — (37 ) — — (85 ) — (204 ) (1,213 ) Recoveries 43 14 — — — — — 5 35 16 113 Net charge-offs (770 ) (60 ) — — (37 ) — — (80 ) 35 (188 ) (1,100 ) Ending balance $ 5,271 $ 2,847 $ 121 $ 301 $ 1,470 $ 510 $ 211 $ 1,646 $ 472 $ 304 $ 13,153 As % of ALLL 40.1 % 21.6 % 0.9 % 2.3 % 11.2 % 3.9 % 1.6 % 12.5 % 3.6 % 2.3 % 100.0 % ALLL: Individually evaluated $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — Collectively evaluated 5,271 2,847 121 301 1,470 510 211 1,646 472 304 13,153 Ending balance $ 5,271 $ 2,847 $ 121 $ 301 $ 1,470 $ 510 $ 211 $ 1,646 $ 472 $ 304 $ 13,153 Loans: Individually evaluated $ 2,927 $ 1,506 $ — $ 222 $ 1,686 $ 603 $ — $ 2,750 $ 233 $ 12 $ 9,939 Collectively evaluated 681,993 439,847 35,625 53,222 341,966 79,996 30,926 355,091 111,095 26,481 2,156,242 Total loans $ 684,920 $ 441,353 $ 35,625 $ 53,444 $ 343,652 $ 80,599 $ 30,926 $ 357,841 $ 111,328 $ 26,493 $ 2,166,181 Less ALLL 5,271 2,847 121 301 1,470 510 211 1,646 472 304 13,153 Net loans $ 679,649 $ 438,506 $ 35,504 $ 53,143 $ 342,182 $ 80,089 $ 30,715 $ 356,195 $ 110,856 $ 26,189 $ 2,153,028 As a further breakdown, the ALLL is summarized by originated and acquired as follows. Originated – Year Ended December 31, 2018 (in thousands) Commercial & industrial Owner- occupied CRE AG production AG real estate CRE investment Construction & land development Residential construction Residential first mortgage Residential junior mortgage Retail & other Total ALLL: Beginning balance $ 4,192 $ 2,115 $ 112 $ 235 $ 1,154 $ 628 $ 200 $ 1,297 $ 409 $ 200 $ 10,542 Provision 1,262 385 (2 ) 20 113 (197 ) 11 187 (31 ) 266 2,014 Charge-offs (813 ) (64 ) — — (37 ) — — (85 ) — (201 ) (1,200 ) Recoveries 42 3 — — — — — 1 30 16 92 Net charge-offs (771 ) (61 ) — — (37 ) — — (84 ) 30 (185 ) (1,108 ) Ending balance $ 4,683 $ 2,439 $ 110 $ 255 $ 1,230 $ 431 $ 211 $ 1,400 $ 408 $ 281 $ 11,448 As % of ALLL 40.9 % 21.3 % 1.0 % 2.2 % 10.7 % 3.8 % 1.8 % 12.2 % 3.6 % 2.5 % 100.0 % ALLL: Individually evaluated $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — Collectively evaluated 4,683 2,439 110 255 1,230 431 211 1,400 408 281 11,448 Ending balance $ 4,683 $ 2,439 $ 110 $ 255 $ 1,230 $ 431 $ 211 $ 1,400 $ 408 $ 281 $ 11,448 Loans: Individually evaluated $ 227 $ 321 $ — $ — $ — $ — $ — $ — $ — $ — $ 548 Collectively evaluated 567,873 283,210 11,113 31,374 171,087 66,478 30,926 220,368 78,379 23,809 1,484,617 Total loans $ 568,100 $ 283,531 $ 11,113 $ 31,374 $ 171,087 $ 66,478 $ 30,926 $ 220,368 $ 78,379 $ 23,809 $ 1,485,165 Less ALLL 4,683 2,439 110 255 1,230 431 211 1,400 408 281 11,448 Net loans $ 563,417 $ 281,092 $ 11,003 $ 31,119 $ 169,857 $ 66,047 $ 30,715 $ 218,968 $ 77,971 $ 23,528 $ 1,473,717 Acquired – Year Ended December 31, 2018 (in thousands) Commercial & industrial Owner- occupied CRE AG production AG real estate CRE investment Construction & land development Residential construction Residential first mortgage Residential junior mortgage Retail & other Total ALLL: Beginning balance $ 742 $ 492 $ 17 $ 61 $ 234 $ 98 $ 51 $ 312 $ 79 $ 25 $ 2,111 Provision (155 ) (85 ) (6 ) (15 ) 6 (19 ) (51 ) (70 ) (20 ) 1 (414 ) Charge-offs — (10 ) — — — — — — — (3 ) (13 ) Recoveries 1 11 — — — — — 4 5 — 21 Net charge-offs 1 1 — — — — — 4 5 (3 ) 8 Ending balance $ 588 $ 408 $ 11 $ 46 $ 240 $ 79 $ — $ 246 $ 64 $ 23 $ 1,705 As % of ALLL 34.5 % 23.9 % 0.6 % 2.7 % 14.1 % 4.6 % — % 14.4 % 3.8 % 1.4 % 100.0 % ALLL: Individually evaluated $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — Collectively evaluated 588 408 11 46 240 79 — 246 64 23 1,705 Ending balance $ 588 $ 408 $ 11 $ 46 $ 240 $ 79 $ — $ 246 $ 64 $ 23 $ 1,705 Loans: Individually evaluated $ 2,700 $ 1,185 $ — $ 222 $ 1,686 $ 603 $ — $ 2,750 $ 233 $ 12 $ 9,391 Collectively evaluated 114,120 156,637 24,512 21,848 170,879 13,518 — 134,723 32,716 2,672 671,625 Total loans $ 116,820 $ 157,822 $ 24,512 $ 22,070 $ 172,565 $ 14,121 $ — $ 137,473 $ 32,949 $ 2,684 $ 681,016 Less ALLL 588 408 11 46 240 79 — 246 64 23 1,705 Net loans $ 116,232 $ 157,414 $ 24,501 $ 22,024 $ 172,325 $ 14,042 $ — $ 137,227 $ 32,885 $ 2,661 $ 679,311 For comparison, the following tables present the balance and activity in the ALLL by portfolio segment and the recorded investment in loans by portfolio segment for the year ended December 31, 2017 . TOTAL – Year Ended December 31, 2017 (in thousands) Commercial & industrial Owner- occupied CRE AG production AG real estate CRE investment Construction & land development Residential construction Residential first mortgage Residential junior mortgage Retail & other Total ALLL: Beginning balance $ 3,919 $ 2,867 $ 150 $ 285 $ 1,124 $ 774 $ 304 $ 1,784 $ 461 $ 152 $ 11,820 Provision 2,419 (290 ) (21 ) 11 263 (35 ) (53 ) (192 ) 96 127 2,325 Charge-offs (1,442 ) — — — — (13 ) — (8 ) (72 ) (69 ) (1,604 ) Recoveries 38 30 — — 1 — — 25 3 15 112 Net charge-offs (1,404 ) 30 — — 1 (13 ) — 17 (69 ) (54 ) (1,492 ) Ending balance $ 4,934 $ 2,607 $ 129 $ 296 $ 1,388 $ 726 $ 251 $ 1,609 $ 488 $ 225 $ 12,653 As % of ALLL 39.0 % 20.6 % 1.0 % 2.3 % 11.0 % 5.7 % 2.0 % 12.7 % 3.9 % 1.8 % 100.0 % ALLL: Individually evaluated $ 163 $ — $ — $ — $ — $ — $ — $ — $ — $ — $ 163 Collectively evaluated 4,771 2,607 129 296 1,388 726 251 1,609 488 225 12,490 Ending balance $ 4,934 $ 2,607 $ 129 $ 296 $ 1,388 $ 726 $ 251 $ 1,609 $ 488 $ 225 $ 12,653 Loans: Individually evaluated $ 5,870 $ 1,689 $ — $ 248 $ 5,290 $ 1,053 $ 80 $ 2,801 $ 178 $ 12 $ 17,221 Collectively evaluated 631,467 428,354 35,455 51,530 309,173 88,607 36,915 360,551 105,849 22,803 2,070,704 Total loans $ 637,337 $ 430,043 $ 35,455 $ 51,778 $ 314,463 $ 89,660 $ 36,995 $ 363,352 $ 106,027 $ 22,815 $ 2,087,925 Less ALLL 4,934 2,607 129 296 1,388 726 251 1,609 488 225 12,653 Net loans $ 632,403 $ 427,436 $ 35,326 $ 51,482 $ 313,075 $ 88,934 $ 36,744 $ 361,743 $ 105,539 $ 22,590 $ 2,075,272 As a further breakdown, the December 31, 2017 ALLL is summarized by originated and acquired as follows. Originated – Year Ended December 31, 2017 (in thousands) Commercial & industrial Owner- occupied CRE AG production AG real estate CRE investment Construction & land development Residential construction Residential first mortgage Residential junior mortgage Retail & other Total ALLL: Beginning balance $ 3,150 $ 2,263 $ 122 $ 222 $ 893 $ 656 $ 266 $ 1,372 $ 373 $ 132 $ 9,449 Provision 2,429 (172 ) (10 ) 13 261 (28 ) (66 ) (69 ) 105 122 2,585 Charge-offs (1,388 ) — — — — — — (8 ) (72 ) (69 ) (1,537 ) Recoveries 1 24 — — — — — 2 3 15 45 Net charge-offs (1,387 ) 24 — — — — — (6 ) (69 ) (54 ) (1,492 ) Ending balance $ 4,192 $ 2,115 $ 112 $ 235 $ 1,154 $ 628 $ 200 $ 1,297 $ 409 $ 200 $ 10,542 As % of ALLL 39.8 % 20.1 % 1.1 % 2.2 % 10.9 % 6.0 % 1.9 % 12.3 % 3.9 % 1.8 % 100.0 % ALLL: Individually evaluated $ 163 $ — $ — $ — $ — $ — $ — $ — $ — $ — $ 163 Collectively evaluated 4,029 2,115 112 235 1,154 628 200 1,297 409 200 10,379 Ending balance $ 4,192 $ 2,115 $ 112 $ 235 $ 1,154 $ 628 $ 200 $ 1,297 $ 409 $ 200 $ 10,542 Loans: Individually evaluated $ 2,189 $ — $ — $ — $ 549 $ — $ — $ 253 $ 12 $ — $ 3,003 Collectively evaluated 486,411 237,548 11,102 27,831 113,313 56,061 33,615 190,933 65,631 18,254 1,240,699 Total loans $ 488,600 $ 237,548 $ 11,102 $ 27,831 $ 113,862 $ 56,061 $ 33,615 $ 191,186 $ 65,643 $ 18,254 $ 1,243,702 Less ALLL 4,192 2,115 112 235 1,154 628 200 1,297 409 200 10,542 Net loans $ 484,408 $ 235,433 $ 10,990 $ 27,596 $ 112,708 $ 55,433 $ 33,415 $ 189,889 $ 65,234 $ 18,054 $ 1,233,160 Acquired – Year Ended December 31, 2017 (in thousands) Commercial & industrial Owner- occupied CRE AG production AG real estate CRE investment Construction & land development Residential construction Residential first mortgage Residential junior mortgage Retail & other Total ALLL: Beginning balance $ 769 $ 604 $ 28 $ 63 $ 231 $ 118 $ 38 $ 412 $ 88 $ 20 $ 2,371 Provision (10 ) (118 ) (11 ) (2 ) 2 (7 ) 13 (123 ) (9 ) 5 (260 ) Charge-offs (54 ) — — — — (13 ) — — — — (67 ) Recoveries 37 6 — — 1 — — 23 — — 67 Net charge-offs (17 ) 6 — — 1 (13 ) — 23 — — — Ending balance $ 742 $ 492 $ 17 $ 61 $ 234 $ 98 $ 51 $ 312 $ 79 $ 25 $ 2,111 As % of ALLL 35.1 % 23.3 % 0.8 % 2.9 % 11.1 % 4.6 % 2.4 % 14.8 % 3.7 % 1.3 % 100.0 % ALLL: Individually evaluated $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — Collectively evaluated 742 492 17 61 234 98 51 312 79 25 2,111 Ending balance $ 742 $ 492 $ 17 $ 61 $ 234 $ 98 $ 51 $ 312 $ 79 $ 25 $ 2,111 Loans: Individually evaluated $ 3,681 $ 1,689 $ — $ 248 $ 4,741 $ 1,053 $ 80 $ 2,548 $ 166 $ 12 $ 14,218 Collectively evaluated 145,056 190,806 24,353 23,699 195,860 32,546 3,300 169,618 40,218 4,549 830,005 Total loans $ 148,737 $ 192,495 $ 24,353 $ 23,947 $ 200,601 $ 33,599 $ 3,380 $ 172,166 $ 40,384 $ 4,561 $ 844,223 Less ALLL 742 492 17 61 234 98 51 312 79 25 2,111 Net loans $ 147,995 $ 192,003 $ 24,336 $ 23,886 $ 200,367 $ 33,501 $ 3,329 $ 171,854 $ 40,305 $ 4,536 $ 842,112 As a further breakdown, the ALLL is summarized by originated and acquired as follows. Originated – Year Ended December 31, 2018 (in thousands) Commercial & industrial Owner- occupied CRE AG production AG real estate CRE investment Construction & land development Residential construction Residential first mortgage Residential junior mortgage Retail & other Total ALLL: Beginning balance $ 4,192 $ 2,115 $ 112 $ 235 $ 1,154 $ 628 $ 200 $ 1,297 $ 409 $ 200 $ 10,542 Provision 1,262 385 (2 ) 20 113 (197 ) 11 187 (31 ) 266 2,014 Charge-offs (813 ) (64 ) — — (37 ) — — (85 ) — (201 ) (1,200 ) Recoveries 42 3 — — — — — 1 30 16 92 Net charge-offs (771 ) (61 ) — — (37 ) — — (84 ) 30 (185 ) (1,108 ) Ending balance $ 4,683 $ 2,439 $ 110 $ 255 $ 1,230 $ 431 $ 211 $ 1,400 $ 408 $ 281 $ 11,448 As % of ALLL 40.9 % 21.3 % 1.0 % 2.2 % 10.7 % 3.8 % 1.8 % 12.2 % 3.6 % 2.5 % 100.0 % ALLL: Individually evaluated $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — Collectively evaluated 4,683 2,439 110 255 1,230 431 211 1,400 408 281 11,448 Ending balance $ 4,683 $ 2,439 $ 110 $ 255 $ 1,230 $ 431 $ 211 $ 1,400 $ 408 $ 281 $ 11,448 Loans: Individually evaluated $ 227 $ 321 $ — $ — $ — $ — $ — $ — $ — $ — $ 548 Collectively evaluated 567,873 283,210 11,113 31,374 171,087 66,478 30,926 220,368 78,379 23,809 1,484,617 Total loans $ 568,100 $ 283,531 $ 11,113 $ 31,374 $ 171,087 $ 66,478 $ 30,926 $ 220,368 $ 78,379 $ 23,809 $ 1,485,165 Less ALLL 4,683 2,439 110 255 1,230 431 211 1,400 408 281 11,448 Net loans $ 563,417 $ 281,092 $ 11,003 $ 31,119 $ 169,857 $ 66,047 $ 30,715 $ 218,968 $ 77,971 $ 23,528 $ 1,473,717 Acquired – Year Ended December 31, 2018 (in thousands) Commercial & industrial Owner- occupied CRE AG production AG real estate CRE investment Construction & land development Residential construction Residential first mortgage Residential junior mortgage Retail & other Total ALLL: Beginning balance $ 742 $ 492 $ 17 $ 61 $ 234 $ 98 $ 51 $ 312 $ 79 $ 25 $ 2,111 Provision (155 ) (85 ) (6 ) (15 ) 6 (19 ) (51 ) (70 ) (20 ) 1 (414 ) Charge-offs — (10 ) — — — — — — — (3 ) (13 ) Recoveries 1 11 — — — — — 4 5 — 21 Net charge-offs 1 1 — — — — — 4 5 (3 ) 8 Ending balance $ 588 $ 408 $ 11 $ 46 $ 240 $ 79 $ — $ 246 $ 64 $ 23 $ 1,705 As % of ALLL 34.5 % 23.9 % 0.6 % 2.7 % 14.1 % 4.6 % — % 14.4 % 3.8 % 1.4 % 100.0 % ALLL: Individually evaluated $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — Collectively evaluated 588 408 11 46 240 79 — 246 64 23 1,705 Ending balance $ 588 $ 408 $ 11 $ 46 $ 240 $ 79 $ — $ 246 $ 64 $ 23 $ 1,705 Loans: Individually evaluated $ 2,700 $ 1,185 $ — $ 222 $ 1,686 $ 603 $ — $ 2,750 $ 233 $ 12 $ 9,391 Collectively evaluated 114,120 156,637 24,512 21,848 170,879 13,518 — 134,723 32,716 2,672 671,625 Total loans $ 116,820 $ 157,822 $ 24,512 $ 22,070 $ 172,565 $ 14,121 $ — $ 137,473 $ 32,949 $ 2,684 $ 681,016 Less ALLL 588 408 11 46 240 79 — 246 64 23 1,705 Net loans $ 116,232 $ 157,414 $ 24,501 $ 22,024 $ 172,325 $ 14,042 $ — $ 137,227 $ 32,885 $ 2,661 $ 679,311
Schedule of nonaccrual loans by portfolio segment and further breakdown summarized by originated and acquired	The following tables present nonaccrual loans by portfolio segment in total and then as a further breakdown by originated or acquired. Total Nonaccrual Loans (in thousands) December 31, 2018 % to Total December 31, 2017 % to Total Commercial & industrial $ 2,816 52 % $ 6,016 46 % Owner-occupied CRE 673 12 533 4 AG production — — — — AG real estate 164 3 186 1 CRE investment 210 4 4,531 35 Construction & land development 80 1 — — Residential construction 1 — 80 1 Residential first mortgage 1,265 23 1,587 12 Residential junior mortgage 262 5 158 1 Retail & other — — 4 — Nonaccrual loans $ 5,471 100 % $ 13,095 100 % Percent of total loans 0.2 % 0.6 % December 31, 2018 December 31, 2017 (in thousands) Originated Amount % of Total Acquired Amount % of Total Originated Amount % of Total Acquired Amount % of Total Commercial & industrial $ 352 25 % $ 2,464 61 % $ 2,296 70 % $ 3,720 38 % Owner-occupied CRE 362 26 311 8 86 3 447 4 AG production — — — — — — — — AG real estate — — 164 4 — — 186 2 CRE investment — — 210 5 549 17 3,982 41 Construction & land development — — 80 2 — — — — Residential construction 1 — — — — — 80 1 Residential first mortgage 629 45 636 15 331 10 1,256 13 Residential junior mortgage 65 4 197 5 12 — 146 1 Retail & other — — — — 4 — — — Nonaccrual loans $ 1,409 100 % $ 4,062 100 % $ 3,278 100 % $ 9,817 100 % Percent of nonaccrual loans 25.8 % 74.2 % 25.0 % 75.0 %
Schedule of past due loans by portfolio segment and further breakdown summarized by originated and acquired	The following tables present past due loans by portfolio segment. December 31, 2018 (in thousands) 30-89 Days Past Due (accruing) 90 Days & Over or nonaccrual Current Total Commercial & industrial $ — $ 2,816 $ 682,104 $ 684,920 Owner-occupied CRE 557 673 440,123 441,353 AG production 19 — 35,606 35,625 AG real estate 35 164 53,245 53,444 CRE investment 180 210 343,262 343,652 Construction & land development — 80 80,519 80,599 Residential construction — 1 30,925 30,926 Residential first mortgage 758 1,265 355,818 357,841 Residential junior mortgage 12 262 111,054 111,328 Retail & other 10 — 26,483 26,493 Total loans $ 1,571 $ 5,471 $ 2,159,139 $ 2,166,181 Percent of total loans 0.1 % 0.2 % 99.7 % 100.0 % December 31, 2017 (in thousands) 30-89 Days Past Due (accruing) 90 Days & Over or nonaccrual Current Total Commercial & industrial $ 211 $ 6,016 $ 631,110 $ 637,337 Owner-occupied CRE 671 533 428,839 430,043 AG production 30 — 35,425 35,455 AG real estate — 186 51,592 51,778 CRE investment — 4,531 309,932 314,463 Construction & land development 76 — 89,584 89,660 Residential construction 587 80 36,328 36,995 Residential first mortgage 1,039 1,587 360,726 363,352 Residential junior mortgage 14 158 105,855 106,027 Retail & other 4 4 22,807 22,815 Total loans $ 2,632 $ 13,095 $ 2,072,198 $ 2,087,925 Percent of total loans 0.1 % 0.6 % 99.3 % 100.0 % December 31, 2017 (in thousands) 30-89 Days Past Due (accruing) 90 Days & Over or nonaccrual Current Total Commercial & industrial $ 211 $ 6,016 $ 631,110 $ 637,337 Owner-occupied CRE 671 533 428,839 430,043 AG production 30 — 35,425 35,455 AG real estate — 186 51,592 51,778 CRE investment — 4,531 309,932 314,463 Construction & land development 76 — 89,584 89,660 Residential construction 587 80 36,328 36,995 Residential first mortgage 1,039 1,587 360,726 363,352 Residential junior mortgage 14 158 105,855 106,027 Retail & other 4 4 22,807 22,815 Total loans $ 2,632 $ 13,095 $ 2,072,198 $ 2,087,925 Percent of total loans 0.1 % 0.6 % 99.3 % 100.0 %
Schedule of total loans by risk categories	December 31, 2018 (in thousands) Grades 1- 4 Grade 5 Grade 6 Grade 7 Grade 8 Grade 9 Total Commercial & industrial $ 649,475 $ 16,145 $ 6,178 $ 13,122 $ — $ — $ 684,920 Owner-occupied CRE 405,198 22,776 6,569 6,810 — — 441,353 AG production 29,363 3,302 2,351 609 — — 35,625 AG real estate 46,248 3,246 2,983 967 — — 53,444 CRE investment 334,080 6,792 — 2,780 — — 343,652 Construction & land development 75,365 5,138 16 80 — — 80,599 Residential construction 30,926 — — — — — 30,926 Residential first mortgage 353,239 1,406 510 2,686 — — 357,841 Residential junior mortgage 111,037 17 — 274 — — 111,328 Retail & other 26,493 — — — — — 26,493 Total loans $ 2,061,424 $ 58,822 $ 18,607 $ 27,328 $ — $ — $ 2,166,181 Percent of total loans 95.1 % 2.7 % 0.9 % 1.3 % — % — % 100.0 % December 31, 2017 (in thousands) Grades 1- 4 Grade 5 Grade 6 Grade 7 Grade 8 Grade 9 Total Commercial & industrial $ 597,854 $ 12,999 $ 16,129 $ 10,355 $ — $ — $ 637,337 Owner-occupied CRE 397,357 23,340 6,442 2,904 — — 430,043 AG production 30,431 4,000 — 1,024 — — 35,455 AG real estate 44,321 4,873 — 2,584 — — 51,778 CRE investment 299,926 8,399 190 5,948 — — 314,463 Construction & land development 86,011 2,758 17 874 — — 89,660 Residential construction 36,915 — — 80 — — 36,995 Residential first mortgage 358,067 1,868 683 2,734 — — 363,352 Residential junior mortgage 105,736 117 — 174 — — 106,027 Retail & other 22,811 — — 4 — — 22,815 Total loans $ 1,979,429 $ 58,354 $ 23,461 $ 26,681 $ — $ — $ 2,087,925 Percent of total loans 94.8 % 2.8 % 1.1 % 1.3 % — % — % 100.0 %
Schedule of impaired loans and further breakdown summarized by originated and acquired	The following tables present impaired loans. December 31, 2018 (in thousands) Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized Commercial & industrial $ 2,927 $ 6,736 $ — $ 4,041 $ 660 Owner-occupied CRE 1,506 1,833 — 1,659 137 AG production — — — — — AG real estate 222 281 — 238 26 CRE investment 1,686 2,484 — 1,606 163 Construction & land development 603 1,506 — 603 21 Residential construction — — — — — Residential first mortgage 2,750 2,907 — 2,478 176 Residential junior mortgage 233 262 — 62 15 Retail & other 12 12 — 12 1 Total $ 9,939 $ 16,021 $ — $ 10,699 $ 1,199 Originated impaired loans $ 548 $ 548 $ — $ 899 $ 154 Acquired impaired loans 9,391 15,473 — 9,800 1,045 Total $ 9,939 $ 16,021 $ — $ 10,699 $ 1,199 December 31, 2017 (in thousands) Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized Commercial & industrial $ 5,870 $ 10,063 $ 163 $ 6,586 $ 718 Owner-occupied CRE 1,689 2,256 — 1,333 132 AG production — 10 — — — AG real estate 248 307 — 233 26 CRE investment 5,290 8,102 — 5,411 465 Construction & land development 1,053 1,053 — 813 57 Residential construction 80 983 — 91 27 Residential first mortgage 2,801 3,653 — 2,177 180 Residential junior mortgage 178 507 — 154 17 Retail & other 12 14 — 12 1 Total $ 17,221 $ 26,948 $ 163 $ 16,810 $ 1,623 Originated impaired loans $ 3,003 $ 3,003 $ 163 $ 2,964 $ 241 Acquired impaired loans 14,218 23,945 — 13,846 1,382 Total $ 17,221 $ 26,948 $ 163 $ 16,810 $ 1,623
Schedule of non accretable discount	Nonaccretable discount on PCI loans: Years Ended December 31, (in thousands) 2018 2017 Balance at beginning of period $ 9,471 $ 14,327 Acquired balance, net — 8,352 Accretion to loan interest income (1,976 ) (7,995 ) Transferred to accretable (990 ) (1,936 ) Disposals of loans (97 ) (3,277 ) Balance at end of period $ 6,408 $ 9,471

PREMISES AND EQUIPMENT (Tables)

PREMISES AND EQUIPMENT (Tables)	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Schedule of Premises and equipment, less accumulated depreciation and amortization	Premises and equipment, less accumulated depreciation and amortization, is summarized as follows. (in thousands) December 31, 2018 December 31, 2017 Land $ 6,220 $ 5,987 Land improvements 3,842 3,591 Building and improvements 42,238 39,661 Leasehold improvements 4,092 4,092 Furniture and equipment 18,590 16,342 74,982 69,673 Less accumulated depreciation and amortization 26,809 22,522 Premises and equipment, net $ 48,173 $ 47,151
Schedule of minimum annual rentals under non-cancelable lease agreements	At December 31, 2018 , the approximate minimum annual rentals under these non-cancelable lease agreements with remaining terms in excess of one year are as follows. Years Ending December 31, (in thousands) 2019 $ 1,073 2020 1,065 2021 956 2022 902 2023 665 Thereafter 742 Total $ 5,403

GOODWILL AND OTHER INTANGIBLE_2

GOODWILL AND OTHER INTANGIBLES AND MORTGAGE SERVICING RIGHTS (Tables)	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of goodwill and other intangibles included in other assets	A summary of goodwill and other intangibles was as follows. (in thousands) December 31, 2018 December 31, 2017 Goodwill $ 107,366 $ 107,366 Core deposit intangibles 12,562 16,477 Customer list intangibles 4,379 4,563 Other intangibles 16,941 21,040 Goodwill and other intangibles, net $ 124,307 $ 128,406
Schedule of intangible assets	See Note 1 for the Company’s accounting policy for other intangibles and see Note 2 for additional information on the Company’s acquisitions. (in thousands) December 31, 2018 December 31, 2017 Core deposit intangibles: Gross carrying amount $ 29,015 $ 29,015 Accumulated amortization (16,453 ) (12,538 ) Net book value $ 12,562 $ 16,477 Additions during the period $ — $ 3,670 Amortization during the period $ 3,915 $ 4,294 Customer list intangibles: Gross carrying amount $ 5,523 5,233 Accumulated amortization (1,144 ) (670 ) Net book value $ 4,379 $ 4,563 Additions during the period $ 290 $ 870 Amortization during the period $ 474 $ 401
Schedule of mortgage servicing rights	A summary of the changes in the MSR asset was as follows. (in thousands) December 31, 2018 December 31, 2017 MSR asset: MSR asset at beginning of year $ 3,187 $ 1,922 Capitalized MSR 1,203 876 MSR asset acquired — 874 Amortization during the period (641 ) (485 ) MSR asset at end of year $ 3,749 $ 3,187 Fair value of MSR asset at end of period $ 6,347 $ 4,097 Residential mortgage loans serviced for others $ 603,446 $ 518,419 Net book value of MSR asset to loans serviced for others 0.62 % 0.61 %
Schedule of estimated future amortization expense for amortizing intangible assets	The actual amortization expense the Company recognizes in any given period may be significantly different depending upon acquisition or sale activities, changes in interest rates, prepayment speeds, market conditions, regulatory requirements and events or circumstances that indicate the carrying amount of an asset may not be recoverable. (in thousands) Core deposit intangibles Customer list intangibles MSR asset Years Ending December 31, 2019 $ 3,337 $ 507 $ 697 2020 2,657 507 680 2021 2,167 507 531 2022 1,735 507 531 2023 1,273 483 419 Thereafter 1,393 1,868 891 Total $ 12,562 $ 4,379 $ 3,749

OTHER REAL ESTATE OWNED (Tables

OTHER REAL ESTATE OWNED (Tables)	12 Months Ended
	Dec. 31, 2018
Real Estate [Abstract]
Schedule of summary of OREO	A summary of OREO, which is included in other assets in the consolidated balance sheets, for the periods indicated is as follows. Years Ended December 31, (in thousands) 2018 2017 Balance at beginning of period $ 1,294 $ 2,059 Transfers in at net realizable value 607 583 Sales proceeds (2,824 ) (1,724 ) Net gain from sales 1,032 258 Write-downs (120 ) (127 ) Additions for new construction 431 — Acquired balance, net — 245 Balance at end of period $ 420 $ 1,294

DEPOSITS (Tables)

DEPOSITS (Tables)	12 Months Ended
	Dec. 31, 2018
Deposits [Abstract]
Schedule of maturities of time deposits	At December 31, 2018 , the scheduled maturities of time deposits were as follows. Years Ending December 31, (in thousands) 2019 $ 260,993 2020 89,948 2021 22,847 2022 14,760 2023 15,088 Thereafter — Total time deposits $ 403,636

SHORT AND LONG-TERM BORROWINGS

SHORT AND LONG-TERM BORROWINGS (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Schedule of long-term debt instruments	The components of long-term borrowings (borrowing with an original contractual maturity greater than one year) were as follows. (in thousands) December 31, 2018 December 31, 2017 FHLB advances $ 35,252 $ 36,509 Junior subordinated debentures 30,096 29,616 Subordinated notes 11,957 11,921 Total long-term borrowings $ 77,305 $ 78,046
Schedule of maturity of notes payable	The following table shows the maturity schedule of the FHLB advances as of December 31, 2018 . Maturing in: (in thousands) 2019 $ — 2020 10,000 2021 — 2022 25,252 2023 — $ 35,252
Schedule of junior subordinated debentures	All the debentures below are currently callable and may be redeemed in part or in full plus any accrued but unpaid interest. Junior Subordinated Debentures (in thousands) Maturity Date Par 12/31/2018 Unamortized Discount 12/31/2018 Carrying Value 12/31/2017 Carrying Value 2004 Nicolet Bankshares Statutory Trust (1) 7/15/2034 $ 6,186 $ — $ 6,186 $ 6,186 2005 Mid-Wisconsin Financial Services, Inc. (2) 12/15/2035 10,310 (3,371 ) 6,939 6,739 2006 Baylake Corp. (3) 9/30/2036 16,598 (4,120 ) 12,478 12,242 2004 First Menasha Bancshares, Inc. (4) 3/17/2034 5,155 (662 ) 4,493 4,449 Total $ 38,249 $ (8,153 ) $ 30,096 $ 29,616 (1) The interest rate is 8.00% fixed. (2) The debentures, assumed in April 2013 as the result of an acquisition, have a floating rate of the three-month LIBOR plus 1.43% , adjusted quarterly. The interest rates were 4.22% and 3.02% as of December 31, 2018 and 2017 , respectively. (3) The debentures, assumed in April 2016 as a result of an acquisition, have a floating rate of the three-month LIBOR plus 1.35% , adjusted quarterly. The interest rates were 4.15% and 3.04% as of December 31, 2018 and 2017 , respectively. (4) The debentures, assumed in April 2017 as the result of an acquisition, have a floating rate of the three-month LIBOR plus 2.79% , adjusted quarterly. The interest rate was 5.58% and 4.39% as of December 31, 2018 and 2017 , respectively.

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of weighted average assumptions for valuing stock option grants	The weighted average assumptions used in the model for valuing stock option grants were as follows. 2018 2017 2016 Dividend yield — % — % — % Expected volatility 25 % 25 % 25 % Risk-free interest rate 2.61 % 2.14 % 1.52 % Expected average life 7 years 7 years 7 years Weighted average per share fair value of options $ 17.36 $ 15.80 $ 11.04
Schedule of stock incentive plans for options	A summary of the Company’s stock option activity is summarized below. Stock Options Option Shares Outstanding Weighted Average Exercise Price Weighted Average Remaining Life (Years) Aggregate Intrinsic Value (in thousands) Outstanding – December 31, 2015 746,004 $ 21.56 Granted 170,500 36.86 Options assumed in acquisition 91,701 21.03 Exercise of stock options * (84,723 ) 20.98 Forfeited (1,456 ) 21.71 Outstanding – December 31, 2016 922,026 $ 24.39 5.4 $ 21,483 Granted 949,500 49.93 Exercise of stock options * (209,371 ) 18.15 Forfeited (18,900 ) 35.36 Outstanding – December 31, 2017 1,643,255 $ 39.82 8.1 $ 24,525 Granted 15,500 52.76 Exercise of stock options * (70,556 ) 21.52 Forfeited (6,500 ) 39.43 Outstanding – December 31, 2018 1,581,699 $ 40.77 7.4 $ 13,825 Exercisable – December 31, 2018 599,011 $ 32.77 6.3 $ 9,798 *The terms of the stock option agreements permit having a number of shares of stock withheld, the fair market value of which as of the date of exercise is sufficient to satisfy the exercise price and/or tax withholding requirements, and accordingly 6,411 shares, 85,422 shares, and 10,244 shares were surrendered during 2018 , 2017 , and 2016 , respectively.
Schedule of tax withholding requirements options of outstanding	The following options were outstanding at December 31, 2018 . Number of Shares Weighted Average Exercise Price Weighted Average Remaining Life (Years) Outstanding Exercisable Outstanding Exercisable Outstanding Exercisable $9.19 – $20.00 99,267 85,579 $ 16.39 $ 16.38 2.0 1.8 $20.01 – $25.00 202,268 160,468 23.77 23.77 5.8 5.8 $25.01 – $30.00 142,294 87,494 25.97 26.01 6.1 6.1 $30.01 – $40.00 180,370 77,070 35.95 35.41 7.4 7.3 $40.01 – $56.43 957,500 188,400 49.99 49.94 8.5 8.4 1,581,699 599,011 $ 40.77 $ 32.77 7.4 6.3
Schedule of restricted stock	A summary of the Company’s restricted stock activity is summarized below. Restricted Stock Restricted Shares Outstanding Weighted Average Grant Date Fair Value Outstanding – December 31, 2015 36,690 $ 18.70 Granted 31,466 33.68 Vested * (25,207 ) 23.58 Forfeited — — Outstanding – December 31, 2016 42,949 $ 26.80 Granted 9,240 57.75 Vested * (20,514 ) 29.87 Forfeited (755 ) 16.50 Outstanding – December 31, 2017 30,920 $ 34.26 Granted 18,256 52.55 Vested * (19,661 ) 43.58 Forfeited (3 ) 16.50 Outstanding – December 31, 2018 29,512 $ 39.37 *The terms of the restricted stock agreements permit the surrender of shares to the Company upon vesting in order to satisfy applicable tax withholding at the minimum statutory withholding rate, and accordingly 3,948 shares, 5,266 shares, and 7,851 shares were surrendered during 2018 , 2017 , and 2016 , respectively.

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of current and deferred amounts of income tax expense	The current and deferred amounts of income tax expense were as follows. Years Ended December 31, (in thousands) 2018 2017 2016 Current $ 14,967 $ 10,952 $ 12,708 Deferred (1,521 ) 4,430 (3,337 ) Adjustment to the net deferred tax asset for the Tax Cuts and Jobs Act — 885 — Income tax expense $ 13,446 $ 16,267 $ 9,371
Schedule of income tax reconciliation	The differences between the income tax expense recognized and the amount computed by applying the statutory federal income tax rate (21% for 2018 and 35% for 2017 and 2016) to the income before income taxes, less noncontrolling interest, for the years ended as indicated are included in the following table. Years Ended December 31, (in thousands) 2018 2017 2016 Tax on pretax income, less noncontrolling interest, at statutory rates $ 11,441 $ 17,296 $ 9,742 State income taxes, net of federal effect 3,308 2,242 1,339 Tax-exempt interest income (574 ) (1,073 ) (769 ) Non-deductible interest disallowance 30 28 18 Increase in cash surrender value life insurance (508 ) (807 ) (452 ) Non-deductible business entertainment 156 168 106 Non-deductible merger expenses — 65 18 Stock-based employee compensation (50 ) (62 ) (35 ) Adjustment to the net deferred tax asset for the Tax Cuts and Jobs Act — 885 — Deduction attributable to share-based payments — (1,854 ) — Other, net (357 ) (621 ) (596 ) Income tax expense $ 13,446 $ 16,267 $ 9,371
Schedule of net deferred tax asset	The net deferred tax asset includes the following amounts of deferred tax assets and liabilities. (in thousands) December 31, 2018 December 31, 2017 Deferred tax assets: ALLL $ 5,240 $ 7,806 Net operating loss carryforwards 2,202 2,694 Credit carryforwards 43 1,433 Compensation 2,408 1,818 Other 2,549 1,379 Other real estate 103 — Unrealized loss on securities AFS 1,740 794 Total deferred tax assets 14,285 15,924 Deferred tax liabilities: Premises and equipment (821 ) (954 ) Prepaid expenses (693 ) (728 ) Investment securities (1,723 ) (1,589 ) Core deposit and other intangibles (3,563 ) (4,101 ) Estimated section 382 limitation — (543 ) Purchase accounting adjustments to liabilities (2,011 ) (2,113 ) Other (1,021 ) (868 ) Total deferred tax liabilities (9,832 ) (10,896 ) Net deferred tax assets $ 4,453 $ 5,028

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Schedule of summary of the contract or notional amount of exposure to off-balance-sheet risk	A summary of the contract or notional amount of the Company’s exposure to off-balance sheet risk was as follows. (in thousands) December 31, 2018 December 31, 2017 Commitments to extend credit $ 721,098 $ 680,307 Financial standby letters of credit 8,571 8,783 Performance standby letters of credit 7,094 9,080

ASSETS GAINS (LOSSES), NET (Tab

ASSETS GAINS (LOSSES), NET (Tables)	12 Months Ended
	Dec. 31, 2018
Discontinued Operations and Disposal Groups [Abstract]
Schedule of components of the net gain on sale, disposal or write-down of assets	Components of the net gains (losses) on assets are as follows. Years Ended December 31, (in thousands) 2018 2017 2016 Gains (losses) on sales of securities AFS, net $ (212 ) $ 1,220 $ 78 Gains (losses) on equity securities, net 77 — — Gains on sales of OREO, net 1,032 258 666 Write-downs of OREO (120 ) (127 ) — Write-down of other investment — — (500 ) Gains (losses) on sales of other investments, net 187 — — Gains (losses) on sales or dispositions of other assets, net 205 678 (190 ) Asset gains (losses), net $ 1,169 $ 2,029 $ 54

REGULATORY CAPITAL REQUIREMEN_2

REGULATORY CAPITAL REQUIREMENTS (Tables)	12 Months Ended
	Dec. 31, 2018
Banking and Thrift [Abstract]
Schedule of Bank's actual regulatory capital amounts and ratios	The Company’s and the Bank’s actual regulatory capital amounts and ratios are presented in the following table. Actual For Capital Adequacy Purposes To Be Well Capitalized Under Prompt Corrective Action Provisions (2) (in thousands) Amount Ratio (1) Amount Ratio (1) Amount Ratio (1) December 31, 2018 Company Total risk-based capital $ 326,235 12.9 % $ 202,836 8.0 % Tier 1 risk-based capital 301,125 11.9 152,127 6.0 Common equity Tier 1 capital 271,435 10.7 114,095 4.5 Leverage 301,125 10.4 115,483 4.0 Bank Total risk-based capital $ 274,492 10.8 % $ 202,800 8.0 % $ 253,501 10.0 % Tier 1 risk-based capital 261,339 10.3 152,100 6.0 202,800 8.0 Common equity Tier 1 capital 261,339 10.3 114,075 4.5 164,775 6.5 Leverage 261,339 9.1 115,280 4.0 144,100 5.0 December 31, 2017 Company Total risk-based capital $ 299,043 12.8 % $ 186,475 8.0 % Tier 1 risk-based capital 274,469 11.8 139,856 6.0 Common equity Tier 1 capital 245,214 10.5 104,892 4.5 Leverage 274,469 10.0 109,298 4.0 Bank Total risk-based capital $ 267,165 11.5 % $ 186,606 8.0 % $ 233,257 10.0 % Tier 1 risk-based capital 254,512 10.9 139,954 6.0 186,606 8.0 Common equity Tier 1 capital 254,512 10.9 104,966 4.5 151,617 6.5 Leverage 254,512 9.3 109,226 4.0 136,532 5.0 (1) The Total risk-based capital ratio is defined as Tier 1 capital plus tier 2 capital divided by total risk-weighted assets. The Tier 1 risk-based capital ratio is defined as Tier 1 capital divided by total risk-weighted assets. CET1 risk-based capital ratio is defined as Tier 1 capital, with deductions for goodwill and other intangible assets (other than mortgage servicing assets), net of associated deferred tax liabilities, and limitations on the inclusion of deferred tax assets, mortgage servicing assets and investments in other financial institutions, in each case as provided further in the rules, divided by total risk-weighted assets. The Leverage ratio is defined as Tier 1 capital divided by the most recent quarter’s average total assets as adjusted. (2) Prompt corrective action provisions are not applicable at the bank holding company level.

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Schedule of assets and liabilities measured at fair value on a recurring basis	The following table presents the balances of assets and liabilities measured at fair value on a recurring basis for the periods presented. (in thousands) Fair Value Measurements Using Measured at Fair Value on a Recurring Basis: Total Level 1 Level 2 Level 3 December 31, 2018 U.S. government agency securities $ 21,649 $ — $ 21,649 $ — State, county and municipals 160,526 — 160,460 66 Mortgage-backed securities 131,644 — 131,644 — Corporate debt securities 86,325 — 77,901 8,424 Securities AFS $ 400,144 $ — $ 391,654 $ 8,490 Other investments (equity securities) * $ 2,650 $ 2,650 $ — $ — December 31, 2017 U.S. government agency securities $ 26,209 $ — $ 26,209 $ — State, county and municipals 184,044 — 183,386 658 Mortgage-backed securities 155,532 — 155,529 3 Corporate debt securities 36,797 — 28,307 8,490 Equity securities * 2,571 2,571 — — Securities AFS $ 405,153 $ 2,571 $ 393,431 $ 9,151 *Effective January 1, 2018, the Company adopted ASU 2016-01, which requires equity securities with readily determinable fair values to be measured at fair value with changes in the fair value recognized through net income. As a result, the approximately $2.7 million current fair value of equity securities is now reflected within other investments on the consolidated balance sheets instead of securities AFS at December 31, 2018. Prior periods have not been restated for the impact of this accounting change. See Note 1 for additional information on this new accounting standard and see Note 3 additional information on the impact to securities AFS.
Schedule of changes in Level 3 assets measured at fair value on a recurring basis	The following table presents the changes in Level 3 securities AFS measured at fair value on a recurring basis. (in thousands) Years Ended Level 3 Fair Value Measurements: December 31, 2018 December 31, 2017 Balance at beginning of year $ 9,151 $ 9,108 Acquired balances — 189 Paydowns/Sales/Settlements (661 ) (146 ) Balance at end of year $ 8,490 $ 9,151
Schedule of assets measured at fair value on a nonrecurring basis	The following table presents the Company’s assets measured at fair value on a nonrecurring basis, aggregated by the level in the fair value hierarchy within which those measurements fall. (in thousands) Fair Value Measurements Using Measured at Fair Value on a Nonrecurring Basis: Total Level 1 Level 2 Level 3 December 31, 2018 Impaired loans $ 9,939 $ — $ — $ 9,939 OREO 420 — — 420 MSR asset 6,347 — — 6,347 December 31, 2017 Impaired loans $ 17,058 $ — $ — $ 17,058 OREO 1,294 — — 1,294 MSR asset 4,097 — — 4,097
Schedule of estimated fair values of financial instruments	The carrying amounts and estimated fair values of the Company's financial instruments are shown below. December 31, 2018 (in thousands) Carrying Amount Estimated Fair Value Level 1 Level 2 Level 3 Financial assets: Cash and cash equivalents $ 249,526 $ 249,526 $ 249,526 $ — $ — Certificates of deposit in other banks 993 993 — 993 — Securities AFS 400,144 400,144 — 391,654 8,490 Other investments 17,997 17,997 2,650 13,189 2,158 Loans held for sale 1,639 1,662 — 1,662 — Loans, net 2,153,028 2,139,322 — — 2,139,322 BOLI 66,310 66,310 66,310 — — MSR asset 3,749 6,347 — — 6,347 Financial liabilities: Deposits $ 2,614,138 $ 2,614,995 $ — $ — $ 2,614,995 Long-term borrowings 77,305 75,923 — 34,907 41,016 December 31, 2017 (in thousands) Carrying Amount Estimated Fair Value Level 1 Level 2 Level 3 Financial assets: Cash and cash equivalents $ 154,933 $ 154,933 $ 154,933 $ — $ — Certificates of deposit in other banks 1,746 1,746 — 1,746 — Securities AFS 405,153 405,153 2,571 393,431 9,151 Other investments 14,837 14,837 — 13,142 1,695 Loans held for sale 4,666 4,750 — 4,750 — Loans, net 2,075,272 2,068,382 — — 2,068,382 BOLI 64,453 64,453 64,453 — — MSR asset 3,187 4,097 — — 4,097 Financial liabilities: Deposits $ 2,471,064 $ 2,469,456 $ — $ — $ 2,469,456 Long-term borrowings 78,046 77,029 — 36,510 40,519

PARENT COMPANY ONLY FINANCIAL_2

PARENT COMPANY ONLY FINANCIAL INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2018
Condensed Financial Information Disclosure [Abstract]
Schedule of parent company only condensed financial statements	Statements of Cash Flows Years Ended December 31, (in thousands) 2018 2017 2016 Cash Flows From Operating Activities: Net income attributable to Nicolet Bankshares, Inc. $ 41,036 $ 33,150 $ 18,462 Adjustments to reconcile net income to net cash provided by operating activities: Accretion of discounts 515 501 353 (Gain) loss on investments, net (265 ) (1,411 ) 500 Change in other assets and liabilities, net (25 ) (1,384 ) 395 Equity in undistributed (income) loss of subsidiaries, net of dividends (2,847 ) (1,148 ) 15,276 Net cash provided by operating activities 38,414 29,708 34,986 Cash Flows from Investing Activities: Proceeds from sale of investments 708 317 565 Purchases of investments (920 ) — — Net cash paid in business combinations — (19,287 ) (608 ) Net cash used in investing activities (212 ) (18,970 ) (43 ) Cash Flows From Financing Activities: Purchase and retirement of common stock (22,749 ) (15,007 ) (5,201 ) Proceeds from issuance of common stock, net 1,800 4,030 1,900 Capitalized issuance costs, net — — (260 ) Repayment of long-term borrowings — — (3,916 ) Redemption of preferred stock — — (12,200 ) Cash dividends paid on preferred stock — — (633 ) Net cash used in financing activities (20,949 ) (10,977 ) (20,310 ) Net increase (decrease) in cash and due from subsidiary 17,253 (239 ) 14,633 Beginning cash and due from subsidiary 28,026 28,265 13,632 Ending cash and due from subsidiary $ 45,279 $ 28,026 $ 28,265 Condensed parent company only financial statements of Nicolet Bankshares, Inc. follow. Balance Sheets December 31, (in thousands) 2018 2017 Assets Cash and due from subsidiary $ 45,279 $ 28,026 Investments 4,500 4,021 Investments in subsidiaries 384,839 379,640 Goodwill (3,266 ) (3,266 ) Other assets 53 147 Total assets $ 431,405 $ 408,568 Liabilities and Stockholders’ Equity Junior subordinated debentures $ 30,096 $ 29,616 Subordinated notes 11,957 11,921 Other liabilities 2,743 2,853 Stockholders’ equity 386,609 364,178 Total liabilities and stockholders’ equity $ 431,405 $ 408,568 Statements of Income Years Ended December 31, (in thousands) 2018 2017 2016 Interest income $ 52 $ 46 $ 58 Interest expense 2,844 2,415 1,951 Net interest expense (2,792 ) (2,369 ) (1,893 ) Dividend income from subsidiaries 40,775 32,000 35,500 Operating expense (364 ) (369 ) (202 ) Gain (loss) on investments, net 265 1,411 (500 ) Income tax benefit 305 1,329 833 Earnings before equity in undistributed income (loss) of subsidiaries 38,189 32,002 33,738 Equity in undistributed income (loss) of subsidiaries 2,847 1,148 (15,276 ) Net income attributable to Nicolet Bankshares, Inc. $ 41,036 $ 33,150 $ 18,462

EARNINGS PER COMMON SHARE (Tabl

EARNINGS PER COMMON SHARE (Tables)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Schedule of earnings per common share	See Note 1 for the Company’s accounting policy on earnings per common share. Earnings per common share and related information are summarized as follows. Years Ended December 31, (in thousands, except per share data) 2018 2017 2016 Net income attributable to Nicolet Bankshares, Inc. $ 41,036 $ 33,150 $ 18,462 Less preferred stock dividends — — 633 Net income available to common shareholders $ 41,036 $ 33,150 $ 17,829 Weighted average common shares outstanding 9,640 9,440 7,158 Effect of dilutive common stock awards 316 518 356 Diluted weighted average common shares outstanding 9,956 9,958 7,514 Basic earnings per common share $ 4.26 $ 3.51 $ 2.49 Diluted earnings per common share $ 4.12 $ 3.33 $ 2.37

NATURE OF BUSINESS AND SIGNIF_4

NATURE OF BUSINESS AND SIGNIFICANT ACCOUNTING POLICIES - Narrative (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Nature Of Business And Significant Accounting Policies [Line Items]
Other investments	$ 17,997,000	$ 14,837,000
Restricted cash	6,300,000	$ 5,400,000	$ 0
Material loans criteria for ALLL adequacy calculation	$ 250,000
Core deposit intangibles
Nature Of Business And Significant Accounting Policies [Line Items]
Amortized period of core deposit intangible		10 years
Customer list intangibles:
Nature Of Business And Significant Accounting Policies [Line Items]
Amortized period of core deposit intangible		12 years
Nicolet Joint Ventures, LLC (the "JV")
Nature Of Business And Significant Accounting Policies [Line Items]
Ownership percentage	50.00%
United Financial Services Llc | As recorded by Baylake Corp
Nature Of Business And Significant Accounting Policies [Line Items]
Percentage of indirect interest			49.80%
Ownership percentage purchased by company			99.20%
Payment made for acquisition	$ 2,800,000	$ 2,600,000
United Financial Services Llc | Nicolet Joint Ventures, LLC (the "JV")
Nature Of Business And Significant Accounting Policies [Line Items]
Equity income recognized in business acquisition	1,800,000	1,300,000
Carrying value of bank investment	11,500,000	9,700,000
Accounting Standards Update 2016-01
Nature Of Business And Significant Accounting Policies [Line Items]
Other investments	2,700,000	$ 2,600,000
Cumulative effect of adoption of new accounting pronouncement	$ 77,000
Minimum | Securities sold under agreements to repurchase
Nature Of Business And Significant Accounting Policies [Line Items]
Maturity period of repo agreements	1 day
Maximum | Securities sold under agreements to repurchase
Nature Of Business And Significant Accounting Policies [Line Items]
Maturity period of repo agreements	4 days

NATURE OF BUSINESS AND SIGNIF_5

NATURE OF BUSINESS AND SIGNIFICANT ACCOUNTING POLICIES - Estimated useful lives of premises and equipment (Details)	12 Months Ended
	Dec. 31, 2018
Minimum | Building and improvements
Property, Plant and Equipment [Line Items]
Estimated useful lives of new premises and equipment	25 years
Minimum | Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated useful lives of new premises and equipment	5 years
Minimum | Furniture and equipment
Property, Plant and Equipment [Line Items]
Estimated useful lives of new premises and equipment	3 years
Maximum | Building and improvements
Property, Plant and Equipment [Line Items]
Estimated useful lives of new premises and equipment	40 years
Maximum | Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated useful lives of new premises and equipment	15 years
Maximum | Furniture and equipment
Property, Plant and Equipment [Line Items]
Estimated useful lives of new premises and equipment	10 years

ACQUISITIONS - Narrative (Detai

ACQUISITIONS - Narrative (Detail) $ / shares in Units, $ in Thousands	Apr. 28, 2017USD ($)Branch$ / sharesshares	Apr. 29, 2016USD ($)Branch$ / sharesshares	Apr. 29, 2016USD ($)Branch$ / shares	Sep. 30, 2017USD ($)	Dec. 31, 2016Branch	Mar. 31, 2016USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2018USD ($)
Business Acquisition [Line Items]
Common stock issued in acquisitions							$ 0	$ 62,246	$ 165,295
Loans		$ 691,000	$ 691,000
Intangible assets assumed		17,000	17,000
Total consideration paid		164,000
Goodwill		66,000	66,000				$ 107,366	107,366
Fixed assets		63,000	63,000
Customer list intangibles
Business Acquisition [Line Items]
Intangible assets assumed										$ 290
Group of financial advisors
Business Acquisition [Line Items]
Common stock issued amount						$ 2,600
Value of cash consideration						800
Total consideration paid						4,900
Earn-out liability payable						1,500
Goodwill						400
Fixed assets						$ 200
Portion of customer intangible amortized by straight line method						10 years
Adjusted earn-out liability								2,400
Useful life of portion of customer intangible amortized						15 years
Group of financial advisors | Customer list intangibles
Business Acquisition [Line Items]
Intangible assets assumed						$ 4,300		$ 900
As recorded by Baylake Corp
Business Acquisition [Line Items]
Loans		710,000	710,000
Intangible assets assumed		1,000	1,000
Fixed assets		$ 71,000	$ 71,000
Merger Agreement | First Menasha
Business Acquisition [Line Items]
Number of branches | Branch	5
Number of branches closed | Branch	1
Number of common stock issued for consideration | shares	1,309,885
Number of common stock for each outstanding share of common stock	3.126
Common stock issued amount	$ 62,200
Price per share for stock issued in consideration | $ / shares	$ 47.52
Number of trading days	20 days
Value of cash consideration	$ 19,300
Direct stock issuance costs for the merger charged against additional paid in capital	200
Amount of addition in assets	480,000
Loans	351,000
Amount of addition in deposit	375,000
Amount of addition in goodwill	41,000			$ 41,000
Increase in goodwill				1,000
Gain in pre-tax earnings				$ 1,200
Merger Agreement | First Menasha | Core deposit intangibles
Business Acquisition [Line Items]
Intangible assets assumed	$ 4,000
Merger Agreement | As recorded by Baylake Corp
Business Acquisition [Line Items]
Number of branches | Branch			21
Number of branches closed | Branch		1			6
Number of common stock issued for consideration | shares		4,344,243
Number of common stock for each outstanding share of common stock		0.4517
Common stock issued in acquisitions		$ 163,300
Price per share for stock issued in consideration | $ / shares		$ 37.58	$ 37.58
Number of trading days		20 days
Direct stock issuance costs for the merger charged against additional paid in capital		$ 300
Additional consideration for assumed stock options		$ 1,200

ACQUISITIONSn - Baylake Corpora

ACQUISITIONSn - Baylake Corporation Acquisition (Details) - USD ($) $ in Thousands	Apr. 29, 2016	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Cash, cash equivalents and securities available for sale	$ 263,000
Loans	691,000
Other real estate owned	1,000
Core deposit intangible	17,000
Fixed assets and other assets	63,000
Total assets acquired	1,035,000
Deposits	822,000
Junior subordinated debentures, borrowings and other liabilities	115,000
Total liabilities acquired	937,000
Excess of assets acquired over liabilities acquired	98,000
Less: purchase price	164,000
Goodwill	66,000	$ 107,366	$ 107,366
Fair Value Adjustments
Business Acquisition [Line Items]
Cash, cash equivalents and securities available for sale	1,000
Loans	(19,000)
Other real estate owned	(2,000)
Core deposit intangible	16,000
Fixed assets and other assets	(8,000)
Total assets acquired	(12,000)
Deposits	0
Junior subordinated debentures, borrowings and other liabilities	(1,000)
Total liabilities acquired	(1,000)
Excess of assets acquired over liabilities acquired	(11,000)
As recorded by Baylake Corp
Business Acquisition [Line Items]
Cash, cash equivalents and securities available for sale	262,000
Loans	710,000
Other real estate owned	3,000
Core deposit intangible	1,000
Fixed assets and other assets	71,000
Total assets acquired	1,047,000
Deposits	822,000
Junior subordinated debentures, borrowings and other liabilities	116,000
Total liabilities acquired	938,000
Excess of assets acquired over liabilities acquired	$ 109,000

ACQUISITIONS - Unaudited pro fo

ACQUISITIONS - Unaudited pro forma information (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)$ / shares
Business Combinations [Abstract]
Total revenues, net of interest expense	$ 110,788
Net income	$ 23,263
Diluted earnings per share (in dollars per share) | $ / shares	$ 2.55

SECURITIES AVAILABLE FOR SALE -

SECURITIES AVAILABLE FOR SALE - Narrative (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Debt Securities, Available-for-sale [Line Items]
Current fair value of equity securities recognized in other investments	$ 17,997,000	$ 14,837,000
Other-than-temporary impairment charge	0	0	$ 500,000
Available-for-sale Securities
Debt Securities, Available-for-sale [Line Items]
AFS securities pledged as collateral	157,200,000	140,900,000
Accounting Standards Update 2016-01
Debt Securities, Available-for-sale [Line Items]
Recognized gain from adoption of new accounting pronouncment	77,000
Current fair value of equity securities recognized in other investments	2,700,000	$ 2,600,000
Retained Earnings | Accounting Standards Update 2016-01
Debt Securities, Available-for-sale [Line Items]
Cumulative effect adjustment of new accounting pronouncement adoption	$ 900,000

SECURITIES AVAILABLE FOR SALE_2

SECURITIES AVAILABLE FOR SALE - Amortized costs and fair values of securities available for sale (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 407,871	$ 408,093
Gross Unrealized Gains	470	2,073
Gross Unrealized Losses	8,197	5,013
Securities available for sale (“AFS”), at fair value	400,144	405,153
U.S. government agency securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	22,467	26,586
Gross Unrealized Gains	0	0
Gross Unrealized Losses	818	377
Securities available for sale (“AFS”), at fair value	21,649	26,209
State, county and municipals
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	163,702	186,128
Gross Unrealized Gains	76	180
Gross Unrealized Losses	3,252	2,264
Securities available for sale (“AFS”), at fair value	160,526	184,044
Mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	134,350	157,705
Gross Unrealized Gains	328	160
Gross Unrealized Losses	3,034	2,333
Securities available for sale (“AFS”), at fair value	131,644	155,532
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	87,352	36,387
Gross Unrealized Gains	66	449
Gross Unrealized Losses	1,093	39
Securities available for sale (“AFS”), at fair value	$ 86,325	36,797
Equity securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		1,287
Gross Unrealized Gains		1,284
Gross Unrealized Losses		0
Securities available for sale (“AFS”), at fair value		$ 2,571

SECURITIES AVAILABLE FOR SALE_3

SECURITIES AVAILABLE FOR SALE - Gross unrealized losses and the related fair value of securities available for sale (Details) - Accounting Standards Update 2016-01 $ in Thousands	Dec. 31, 2018USD ($)Security	Dec. 31, 2017USD ($)Security
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Fair Value	$ 88,296	$ 218,748
Less than 12 months, Unrealized Losses	907	2,248
12 months or more, Fair Value	251,570	114,863
12 months or more, Unrealized Losses	7,290	2,765
Total, Fair Value	339,866	333,611
Total, Unrealized Losses	$ 8,197	$ 5,013
Number of Securities | Security	680	687
U.S. government agency securities
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Fair Value	$ 0	$ 26,209
Less than 12 months, Unrealized Losses	0	377
12 months or more, Fair Value	21,649	0
12 months or more, Unrealized Losses	818	0
Total, Fair Value	21,649	26,209
Total, Unrealized Losses	$ 818	$ 377
Number of Securities | Security	3	2
US States and Political Subdivisions Debt Securities
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Fair Value	$ 16,136	$ 110,157
Less than 12 months, Unrealized Losses	98	1,097
12 months or more, Fair Value	130,975	49,326
12 months or more, Unrealized Losses	3,154	1,167
Total, Fair Value	147,111	159,483
Total, Unrealized Losses	$ 3,252	$ 2,264
Number of Securities | Security	440	465
Mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Fair Value	$ 20,568	$ 72,210
Less than 12 months, Unrealized Losses	132	735
12 months or more, Fair Value	89,189	65,537
12 months or more, Unrealized Losses	2,902	1,598
Total, Fair Value	109,757	137,747
Total, Unrealized Losses	$ 3,034	$ 2,333
Number of Securities | Security	204	215
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Fair Value	$ 51,592	$ 10,172
Less than 12 months, Unrealized Losses	677	39
12 months or more, Fair Value	9,757	0
12 months or more, Unrealized Losses	416	0
Total, Fair Value	61,349	10,172
Total, Unrealized Losses	$ 1,093	$ 39
Number of Securities | Security	33	5

SECURITIES AVAILABLE FOR SALE_4

SECURITIES AVAILABLE FOR SALE - Amortized cost and fair values of securities available for sale at by contractual maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Amortized Cost, Due in less than one year	$ 17,643
Amortized Cost, Due in one year through five years	168,090
Amortized Cost, Due after five years through ten years	80,819
Amortized Cost, Due after ten years	6,969
Amortized Cost	273,521
Securities AFS, Amortized Cost	407,871	$ 408,093
Fair Value, Due in less than one year	17,624
Fair Value, Due in one year through five years	164,969
Fair Value, Due after five years through ten years	78,904
Fair Value, Due after ten years	7,003
Fair Value	268,500
Securities available for sale (“AFS”), at fair value	400,144	405,153
Mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Securities AFS, Amortized Cost	134,350	157,705
Securities available for sale (“AFS”), at fair value	$ 131,644	$ 155,532

SECURITIES AVAILABLE FOR SALE_5

SECURITIES AVAILABLE FOR SALE - Proceeds from sales of securities AFS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Debt Securities, Available-for-sale [Abstract]
Gross gains	$ 0	$ 1,227	$ 91
Gross losses	(212)	(7)	(13)
Gains (losses) on sales of securities AFS, net	(212)	1,220	78
Proceeds from sales of securities AFS	$ 5,280	$ 10,798	$ 31,442

LOANS, ALLOWANCE FOR LOAN LOS_3

LOANS, ALLOWANCE FOR LOAN LOSSES, AND CREDIT QUALITY - Narrative (Detail)	12 Months Ended
	Dec. 31, 2018USD ($)Loan	Dec. 31, 2017USD ($)Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans classified as troubled debt restructuring, | Loan	4	8
Premodification balance	$ 2,700,000	$ 6,900,000
Postmodification balance	600,000	$ 5,600,000
Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
PCI loans acquired fair value	43,600,000
Loans receivables acquired at fair value in acquisition	9,400,000
Nonaccretable mark	34,400,000
Accretable mark	$ 0

LOANS, ALLOWANCE FOR LOAN LOS_4

LOANS, ALLOWANCE FOR LOAN LOSSES, AND CREDIT QUALITY - Summary of loan composition (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 2,166,181	$ 2,087,925
% of Total	100.00%	100.00%
Less ALLL	$ 13,153	$ 12,653	$ 11,820	$ 10,307
Loans, net	$ 2,153,028	$ 2,075,272
ALLL to loans	0.61%	0.61%
Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 1,485,165	$ 1,243,702
% of Total	100.00%	100.00%
Less ALLL	$ 11,448	$ 10,542	9,449
Loans, net	$ 1,473,717	$ 1,233,160
ALLL to loans	0.77%	0.85%
Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 681,016	$ 844,223
% of Total	100.00%	100.00%
Less ALLL	$ 1,705	$ 2,111	2,371
Loans, net	$ 679,311	$ 842,112
ALLL to loans	0.25%	0.25%
Owner-occupied commercial real estate (“CRE”)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 441,353	$ 430,043
Owner-occupied commercial real estate (“CRE”) | Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount		192,495
Retail & other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 26,493	$ 22,815
% of Total	1.00%	1.00%
Less ALLL	$ 304	$ 225	152
Loans, net	26,189	22,590
Retail & other | Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 23,809	$ 18,254
% of Total	2.00%	2.00%
Less ALLL	$ 281	$ 200	132
Loans, net	23,528	18,054
Retail & other | Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 2,684	$ 4,561
% of Total	1.00%	1.00%
Less ALLL	$ 23	$ 25	20
Loans, net	2,661	4,536
Commercial Portfolio Segment | Commercial & industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 684,920	$ 637,337
% of Total	32.00%	31.00%
Less ALLL	$ 5,271	$ 4,934	3,919
Loans, net	679,649	632,403
Commercial Portfolio Segment | Commercial & industrial | Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 568,100	$ 488,600
% of Total	38.00%	39.00%
Less ALLL	$ 4,683	$ 4,192	3,150
Loans, net	563,417	484,408
Commercial Portfolio Segment | Commercial & industrial | Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 116,820	$ 148,737
% of Total	17.00%	17.00%
Less ALLL	$ 588	$ 742	769
Loans, net	116,232	147,995
Commercial Portfolio Segment | Owner-occupied commercial real estate (“CRE”)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 441,353	$ 430,043
% of Total	20.00%	21.00%
Less ALLL	$ 2,847	$ 2,607	2,867
Loans, net	438,506	427,436
Commercial Portfolio Segment | Owner-occupied commercial real estate (“CRE”) | Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 283,531	$ 237,548
% of Total	19.00%	19.00%
Less ALLL	$ 2,439	$ 2,115	2,263
Loans, net	281,092	235,433
Commercial Portfolio Segment | Owner-occupied commercial real estate (“CRE”) | Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 157,822	$ 192,495
% of Total	23.00%	23.00%
Less ALLL	$ 408	$ 492	604
Loans, net	157,414	192,003
Commercial Portfolio Segment | Agricultural (“AG”) production
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 35,625	$ 35,455
% of Total	2.00%	2.00%
Less ALLL	$ 121	$ 129	150
Loans, net	35,504	35,326
Commercial Portfolio Segment | Agricultural (“AG”) production | Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 11,113	$ 11,102
% of Total	1.00%	1.00%
Less ALLL	$ 110	$ 112	122
Loans, net	11,003	10,990
Commercial Portfolio Segment | Agricultural (“AG”) production | Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 24,512	$ 24,353
% of Total	4.00%	3.00%
Less ALLL	$ 11	$ 17	28
Loans, net	24,501	24,336
Commercial Real Estate Portfolio Segment | AG real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 53,444	$ 51,778
% of Total	2.00%	2.00%
Less ALLL	$ 301	$ 296	285
Loans, net	53,143	51,482
Commercial Real Estate Portfolio Segment | AG real estate | Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 31,374	$ 27,831
% of Total	2.00%	2.00%
Less ALLL	$ 255	$ 235	222
Loans, net	31,119	27,596
Commercial Real Estate Portfolio Segment | AG real estate | Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 22,070	$ 23,947
% of Total	3.00%	3.00%
Less ALLL	$ 46	$ 61	63
Loans, net	22,024	23,886
Commercial Real Estate Portfolio Segment | CRE investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 343,652	$ 314,463
% of Total	16.00%	15.00%
Less ALLL	$ 1,470	$ 1,388	1,124
Loans, net	342,182	313,075
Commercial Real Estate Portfolio Segment | CRE investment | Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 171,087	$ 113,862
% of Total	12.00%	9.00%
Less ALLL	$ 1,230	$ 1,154	893
Loans, net	169,857	112,708
Commercial Real Estate Portfolio Segment | CRE investment | Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 172,565	$ 200,601
% of Total	25.00%	24.00%
Less ALLL	$ 240	$ 234	231
Loans, net	172,325	200,367
Commercial Real Estate Portfolio Segment | Construction & land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 80,599	$ 89,660
% of Total	4.00%	4.00%
Less ALLL	$ 510	$ 726	774
Loans, net	80,089	88,934
Commercial Real Estate Portfolio Segment | Construction & land development | Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 66,478	$ 56,061
% of Total	4.00%	5.00%
Less ALLL	$ 431	$ 628	656
Loans, net	66,047	55,433
Commercial Real Estate Portfolio Segment | Construction & land development | Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 14,121	$ 33,599
% of Total	2.00%	4.00%
Less ALLL	$ 79	$ 98	118
Loans, net	14,042	33,501
Residential | Residential first mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 357,841	$ 363,352
% of Total	17.00%	17.00%
Less ALLL	$ 1,646	$ 1,609	1,784
Loans, net	356,195	361,743
Residential | Residential first mortgage | Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 220,368	$ 191,186
% of Total	15.00%	15.00%
Less ALLL	$ 1,400	$ 1,297	1,372
Loans, net	218,968	189,889
Residential | Residential first mortgage | Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 137,473	$ 172,166
% of Total	20.00%	20.00%
Less ALLL	$ 246	$ 312	412
Loans, net	137,227	171,854
Residential | Residential junior mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 111,328	$ 106,027
% of Total	5.00%	5.00%
Less ALLL	$ 472	$ 488	461
Loans, net	110,856	105,539
Residential | Residential junior mortgage | Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 78,379	$ 65,643
% of Total	5.00%	5.00%
Less ALLL	$ 408	$ 409	373
Loans, net	77,971	65,234
Residential | Residential junior mortgage | Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 32,949	$ 40,384
% of Total	5.00%	5.00%
Less ALLL	$ 64	$ 79	88
Loans, net	32,885	40,305
Residential | Residential construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 30,926	$ 36,995
% of Total	1.00%	2.00%
Less ALLL	$ 211	$ 251	304
Loans, net	30,715	36,744
Residential | Residential construction | Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 30,926	$ 33,615
% of Total	2.00%	3.00%
Less ALLL	$ 211	$ 200	266
Loans, net	30,715	33,415
Residential | Residential construction | Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 0	$ 3,380
% of Total	0.00%	0.00%
Less ALLL	$ 0	$ 51	$ 38
Loans, net	$ 0	$ 3,329

LOANS, ALLOWANCE FOR LOAN LOS_5

LOANS, ALLOWANCE FOR LOAN LOSSES, AND CREDIT QUALITY - Summary of allowance for loan losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
ALLL:
Beginning balance	$ 12,653	$ 11,820	$ 10,307
Provision for loan losses	1,600	2,325	1,800
Charge-offs	(1,213)	(1,604)	(584)
Recoveries	113	112	297
Net charge-offs	(1,100)	(1,492)	(287)
Ending balance	$ 13,153	$ 12,653	$ 11,820

LOANS, ALLOWANCE FOR LOAN LOS_6

LOANS, ALLOWANCE FOR LOAN LOSSES, AND CREDIT QUALITY - Summary of changes in ALLL by portfolio segment for periods - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses
Beginning balance	$ 12,653	$ 11,820	$ 10,307
Provision for loan losses	1,600	2,325	1,800
Charge-offs	(1,213)	(1,604)	(584)
Recoveries	113	112	297
Net charge-offs	(1,100)	(1,492)	(287)
Ending balance	$ 13,153	$ 12,653	11,820
As percent of ALLL	100.00%	100.00%
ALLL:
Individually evaluated	$ 0	$ 163
Collectively evaluated	13,153	12,490
Loans:
Individually evaluated	9,939	17,221
Collectively evaluated	2,156,242	2,070,704
Total loans	2,166,181	2,087,925
Loans, net	2,153,028	2,075,272
Owner-occupied commercial real estate (“CRE”)
Loans:
Total loans	441,353	430,043
Retail & other
Financing Receivable, Allowance for Credit Losses
Beginning balance	225	152
Provision for loan losses	267	127
Charge-offs	(204)	(69)
Recoveries	16	15
Net charge-offs	(188)	(54)
Ending balance	$ 304	$ 225	152
As percent of ALLL	2.30%	1.80%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	304	225
Loans:
Individually evaluated	12	12
Collectively evaluated	26,481	22,803
Total loans	26,493	22,815
Loans, net	26,189	22,590
Commercial Portfolio Segment | Commercial & industrial
Financing Receivable, Allowance for Credit Losses
Beginning balance	4,934	3,919
Provision for loan losses	1,107	2,419
Charge-offs	(813)	(1,442)
Recoveries	43	38
Net charge-offs	(770)	(1,404)
Ending balance	$ 5,271	$ 4,934	3,919
As percent of ALLL	40.10%	39.00%
ALLL:
Individually evaluated	$ 0	$ 163
Collectively evaluated	5,271	4,771
Loans:
Individually evaluated	2,927	5,870
Collectively evaluated	681,993	631,467
Total loans	684,920	637,337
Loans, net	679,649	632,403
Commercial Portfolio Segment | Owner-occupied commercial real estate (“CRE”)
Financing Receivable, Allowance for Credit Losses
Beginning balance	2,607	2,867
Provision for loan losses	300	(290)
Charge-offs	(74)	0
Recoveries	14	30
Net charge-offs	(60)	30
Ending balance	$ 2,847	$ 2,607	2,867
As percent of ALLL	21.60%	20.60%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	2,847	2,607
Loans:
Individually evaluated	1,506	1,689
Collectively evaluated	439,847	428,354
Total loans	441,353	430,043
Loans, net	438,506	427,436
Commercial Portfolio Segment | Agricultural (“AG”) production
Financing Receivable, Allowance for Credit Losses
Beginning balance	129	150
Provision for loan losses	(8)	(21)
Charge-offs	0	0
Recoveries	0	0
Net charge-offs	0	0
Ending balance	$ 121	$ 129	150
As percent of ALLL	0.90%	1.00%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	121	129
Loans:
Individually evaluated	0	0
Collectively evaluated	35,625	35,455
Total loans	35,625	35,455
Loans, net	35,504	35,326
Commercial Real Estate Portfolio Segment | AG real estate
Financing Receivable, Allowance for Credit Losses
Beginning balance	296	285
Provision for loan losses	5	11
Charge-offs	0	0
Recoveries	0	0
Net charge-offs	0	0
Ending balance	$ 301	$ 296	285
As percent of ALLL	2.30%	2.30%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	301	296
Loans:
Individually evaluated	222	248
Collectively evaluated	53,222	51,530
Total loans	53,444	51,778
Loans, net	53,143	51,482
Commercial Real Estate Portfolio Segment | CRE investment
Financing Receivable, Allowance for Credit Losses
Beginning balance	1,388	1,124
Provision for loan losses	119	263
Charge-offs	(37)	0
Recoveries	0	1
Net charge-offs	(37)	1
Ending balance	$ 1,470	$ 1,388	1,124
As percent of ALLL	11.20%	11.00%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	1,470	1,388
Loans:
Individually evaluated	1,686	5,290
Collectively evaluated	341,966	309,173
Total loans	343,652	314,463
Loans, net	342,182	313,075
Commercial Real Estate Portfolio Segment | Construction & land development
Financing Receivable, Allowance for Credit Losses
Beginning balance	726	774
Provision for loan losses	(216)	(35)
Charge-offs	0	(13)
Recoveries	0	0
Net charge-offs	0	(13)
Ending balance	$ 510	$ 726	774
As percent of ALLL	3.90%	5.70%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	510	726
Loans:
Individually evaluated	603	1,053
Collectively evaluated	79,996	88,607
Total loans	80,599	89,660
Loans, net	80,089	88,934
Residential | Residential first mortgage
Financing Receivable, Allowance for Credit Losses
Beginning balance	1,609	1,784
Provision for loan losses	117	(192)
Charge-offs	(85)	(8)
Recoveries	5	25
Net charge-offs	(80)	17
Ending balance	$ 1,646	$ 1,609	1,784
As percent of ALLL	12.50%	12.70%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	1,646	1,609
Loans:
Individually evaluated	2,750	2,801
Collectively evaluated	355,091	360,551
Total loans	357,841	363,352
Loans, net	356,195	361,743
Residential | Residential junior mortgage
Financing Receivable, Allowance for Credit Losses
Beginning balance	488	461
Provision for loan losses	(51)	96
Charge-offs	0	(72)
Recoveries	35	3
Net charge-offs	35	(69)
Ending balance	$ 472	$ 488	461
As percent of ALLL	3.60%	3.90%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	472	488
Loans:
Individually evaluated	233	178
Collectively evaluated	111,095	105,849
Total loans	111,328	106,027
Loans, net	110,856	105,539
Residential | Residential construction
Financing Receivable, Allowance for Credit Losses
Beginning balance	251	304
Provision for loan losses	(40)	(53)
Charge-offs	0	0
Recoveries	0	0
Net charge-offs	0	0
Ending balance	$ 211	$ 251	304
As percent of ALLL	1.60%	2.00%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	211	251
Loans:
Individually evaluated	0	80
Collectively evaluated	30,926	36,915
Total loans	30,926	36,995
Loans, net	30,715	36,744
Originated
Financing Receivable, Allowance for Credit Losses
Beginning balance	10,542	9,449
Provision for loan losses	2,014	2,585
Charge-offs	(1,200)	(1,537)
Recoveries	92	45
Net charge-offs	(1,108)	(1,492)
Ending balance	$ 11,448	$ 10,542	9,449
As percent of ALLL	100.00%	100.00%
ALLL:
Individually evaluated	$ 0	$ 163
Collectively evaluated	11,448	10,379
Loans:
Individually evaluated	548	3,003
Collectively evaluated	1,484,617	1,240,699
Total loans	1,485,165	1,243,702
Loans, net	1,473,717	1,233,160
Originated | Retail & other
Financing Receivable, Allowance for Credit Losses
Beginning balance	200	132
Provision for loan losses	266	122
Charge-offs	(201)	(69)
Recoveries	16	15
Net charge-offs	(185)	(54)
Ending balance	$ 281	$ 200	132
As percent of ALLL	2.50%	1.80%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	281	200
Loans:
Individually evaluated	0	0
Collectively evaluated	23,809	18,254
Total loans	23,809	18,254
Loans, net	23,528	18,054
Originated | Commercial Portfolio Segment | Commercial & industrial
Financing Receivable, Allowance for Credit Losses
Beginning balance	4,192	3,150
Provision for loan losses	1,262	2,429
Charge-offs	(813)	(1,388)
Recoveries	42	1
Net charge-offs	(771)	(1,387)
Ending balance	$ 4,683	$ 4,192	3,150
As percent of ALLL	40.90%	39.80%
ALLL:
Individually evaluated	$ 0	$ 163
Collectively evaluated	4,683	4,029
Loans:
Individually evaluated	227	2,189
Collectively evaluated	567,873	486,411
Total loans	568,100	488,600
Loans, net	563,417	484,408
Originated | Commercial Portfolio Segment | Owner-occupied commercial real estate (“CRE”)
Financing Receivable, Allowance for Credit Losses
Beginning balance	2,115	2,263
Provision for loan losses	385	(172)
Charge-offs	(64)	0
Recoveries	3	24
Net charge-offs	(61)	24
Ending balance	$ 2,439	$ 2,115	2,263
As percent of ALLL	21.30%	20.10%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	2,439	2,115
Loans:
Individually evaluated	321	0
Collectively evaluated	283,210	237,548
Total loans	283,531	237,548
Loans, net	281,092	235,433
Originated | Commercial Portfolio Segment | Agricultural (“AG”) production
Financing Receivable, Allowance for Credit Losses
Beginning balance	112	122
Provision for loan losses	(2)	(10)
Charge-offs	0	0
Recoveries	0	0
Net charge-offs	0	0
Ending balance	$ 110	$ 112	122
As percent of ALLL	1.00%	1.10%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	110	112
Loans:
Individually evaluated	0	0
Collectively evaluated	11,113	11,102
Total loans	11,113	11,102
Loans, net	11,003	10,990
Originated | Commercial Real Estate Portfolio Segment | AG real estate
Financing Receivable, Allowance for Credit Losses
Beginning balance	235	222
Provision for loan losses	20	13
Charge-offs	0	0
Recoveries	0	0
Net charge-offs	0	0
Ending balance	$ 255	$ 235	222
As percent of ALLL	2.20%	2.20%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	255	235
Loans:
Individually evaluated	0	0
Collectively evaluated	31,374	27,831
Total loans	31,374	27,831
Loans, net	31,119	27,596
Originated | Commercial Real Estate Portfolio Segment | CRE investment
Financing Receivable, Allowance for Credit Losses
Beginning balance	1,154	893
Provision for loan losses	113	261
Charge-offs	(37)	0
Recoveries	0	0
Net charge-offs	(37)	0
Ending balance	$ 1,230	$ 1,154	893
As percent of ALLL	10.70%	10.90%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	1,230	1,154
Loans:
Individually evaluated	0	549
Collectively evaluated	171,087	113,313
Total loans	171,087	113,862
Loans, net	169,857	112,708
Originated | Commercial Real Estate Portfolio Segment | Construction & land development
Financing Receivable, Allowance for Credit Losses
Beginning balance	628	656
Provision for loan losses	(197)	(28)
Charge-offs	0	0
Recoveries	0	0
Net charge-offs	0	0
Ending balance	$ 431	$ 628	656
As percent of ALLL	3.80%	6.00%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	431	628
Loans:
Individually evaluated	0	0
Collectively evaluated	66,478	56,061
Total loans	66,478	56,061
Loans, net	66,047	55,433
Originated | Residential | Residential first mortgage
Financing Receivable, Allowance for Credit Losses
Beginning balance	1,297	1,372
Provision for loan losses	187	(69)
Charge-offs	(85)	(8)
Recoveries	1	2
Net charge-offs	(84)	(6)
Ending balance	$ 1,400	$ 1,297	1,372
As percent of ALLL	12.20%	12.30%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	1,400	1,297
Loans:
Individually evaluated	0	253
Collectively evaluated	220,368	190,933
Total loans	220,368	191,186
Loans, net	218,968	189,889
Originated | Residential | Residential junior mortgage
Financing Receivable, Allowance for Credit Losses
Beginning balance	409	373
Provision for loan losses	(31)	105
Charge-offs	0	(72)
Recoveries	30	3
Net charge-offs	30	(69)
Ending balance	$ 408	$ 409	373
As percent of ALLL	3.60%	3.90%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	408	409
Loans:
Individually evaluated	0	12
Collectively evaluated	78,379	65,631
Total loans	78,379	65,643
Loans, net	77,971	65,234
Originated | Residential | Residential construction
Financing Receivable, Allowance for Credit Losses
Beginning balance	200	266
Provision for loan losses	11	(66)
Charge-offs	0	0
Recoveries	0	0
Net charge-offs	0	0
Ending balance	$ 211	$ 200	266
As percent of ALLL	1.80%	1.90%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	211	200
Loans:
Individually evaluated	0	0
Collectively evaluated	30,926	33,615
Total loans	30,926	33,615
Loans, net	30,715	33,415
Acquired
Financing Receivable, Allowance for Credit Losses
Beginning balance	2,111	2,371
Provision for loan losses	(414)	(260)
Charge-offs	(13)	(67)
Recoveries	21	67
Net charge-offs	8	0
Ending balance	$ 1,705	$ 2,111	2,371
As percent of ALLL	100.00%	100.00%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	1,705	2,111
Loans:
Individually evaluated	9,391	14,218
Collectively evaluated	671,625	830,005
Total loans	681,016	844,223
Loans, net	679,311	842,112
Acquired | Owner-occupied commercial real estate (“CRE”)
Loans:
Total loans		192,495
Acquired | Retail & other
Financing Receivable, Allowance for Credit Losses
Beginning balance	25	20
Provision for loan losses	1	5
Charge-offs	(3)	0
Recoveries	0	0
Net charge-offs	(3)	0
Ending balance	$ 23	$ 25	20
As percent of ALLL	1.40%	1.30%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	23	25
Loans:
Individually evaluated	12	12
Collectively evaluated	2,672	4,549
Total loans	2,684	4,561
Loans, net	2,661	4,536
Acquired | Commercial Portfolio Segment | Commercial & industrial
Financing Receivable, Allowance for Credit Losses
Beginning balance	742	769
Provision for loan losses	(155)	(10)
Charge-offs	0	(54)
Recoveries	1	37
Net charge-offs	1	(17)
Ending balance	$ 588	$ 742	769
As percent of ALLL	34.50%	35.10%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	588	742
Loans:
Individually evaluated	2,700	3,681
Collectively evaluated	114,120	145,056
Total loans	116,820	148,737
Loans, net	116,232	147,995
Acquired | Commercial Portfolio Segment | Owner-occupied commercial real estate (“CRE”)
Financing Receivable, Allowance for Credit Losses
Beginning balance	492	604
Provision for loan losses	(85)	(118)
Charge-offs	(10)	0
Recoveries	11	6
Net charge-offs	1	6
Ending balance	$ 408	$ 492	604
As percent of ALLL	23.90%	23.30%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	408	492
Loans:
Individually evaluated	1,185	1,689
Collectively evaluated	156,637	190,806
Total loans	157,822	192,495
Loans, net	157,414	192,003
Acquired | Commercial Portfolio Segment | Agricultural (“AG”) production
Financing Receivable, Allowance for Credit Losses
Beginning balance	17	28
Provision for loan losses	(6)	(11)
Charge-offs	0	0
Recoveries	0	0
Net charge-offs	0	0
Ending balance	$ 11	$ 17	28
As percent of ALLL	0.60%	0.80%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	11	17
Loans:
Individually evaluated	0	0
Collectively evaluated	24,512	24,353
Total loans	24,512	24,353
Loans, net	24,501	24,336
Acquired | Commercial Real Estate Portfolio Segment | AG real estate
Financing Receivable, Allowance for Credit Losses
Beginning balance	61	63
Provision for loan losses	(15)	(2)
Charge-offs	0	0
Recoveries	0	0
Net charge-offs	0	0
Ending balance	$ 46	$ 61	63
As percent of ALLL	2.70%	2.90%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	46	61
Loans:
Individually evaluated	222	248
Collectively evaluated	21,848	23,699
Total loans	22,070	23,947
Loans, net	22,024	23,886
Acquired | Commercial Real Estate Portfolio Segment | CRE investment
Financing Receivable, Allowance for Credit Losses
Beginning balance	234	231
Provision for loan losses	6	2
Charge-offs	0	0
Recoveries	0	1
Net charge-offs	0	1
Ending balance	$ 240	$ 234	231
As percent of ALLL	14.10%	11.10%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	240	234
Loans:
Individually evaluated	1,686	4,741
Collectively evaluated	170,879	195,860
Total loans	172,565	200,601
Loans, net	172,325	200,367
Acquired | Commercial Real Estate Portfolio Segment | Construction & land development
Financing Receivable, Allowance for Credit Losses
Beginning balance	98	118
Provision for loan losses	(19)	(7)
Charge-offs	0	(13)
Recoveries	0	0
Net charge-offs	0	(13)
Ending balance	$ 79	$ 98	118
As percent of ALLL	4.60%	4.60%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	79	98
Loans:
Individually evaluated	603	1,053
Collectively evaluated	13,518	32,546
Total loans	14,121	33,599
Loans, net	14,042	33,501
Acquired | Residential | Residential first mortgage
Financing Receivable, Allowance for Credit Losses
Beginning balance	312	412
Provision for loan losses	(70)	(123)
Charge-offs	0	0
Recoveries	4	23
Net charge-offs	4	23
Ending balance	$ 246	$ 312	412
As percent of ALLL	14.40%	14.80%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	246	312
Loans:
Individually evaluated	2,750	2,548
Collectively evaluated	134,723	169,618
Total loans	137,473	172,166
Loans, net	137,227	171,854
Acquired | Residential | Residential junior mortgage
Financing Receivable, Allowance for Credit Losses
Beginning balance	79	88
Provision for loan losses	(20)	(9)
Charge-offs	0	0
Recoveries	5	0
Net charge-offs	5	0
Ending balance	$ 64	$ 79	88
As percent of ALLL	3.80%	3.70%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	64	79
Loans:
Individually evaluated	233	166
Collectively evaluated	32,716	40,218
Total loans	32,949	40,384
Loans, net	32,885	40,305
Acquired | Residential | Residential construction
Financing Receivable, Allowance for Credit Losses
Beginning balance	51	38
Provision for loan losses	(51)	13
Charge-offs	0	0
Recoveries	0	0
Net charge-offs	0	0
Ending balance	$ 0	$ 51	$ 38
As percent of ALLL	0.00%	2.40%
ALLL:
Individually evaluated	$ 0	$ 0
Collectively evaluated	0	51
Loans:
Individually evaluated	0	80
Collectively evaluated	0	3,300
Total loans	0	3,380
Loans, net	$ 0	$ 3,329

LOANS, ALLOWANCE FOR LOAN LOS_7

LOANS, ALLOWANCE FOR LOAN LOSSES, AND CREDIT QUALITY - Nonaccrual loans by portfolio segment (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 5,471	$ 13,095
% to Non Accrual Total	100.00%	100.00%
Percent of nonaccrual loans	0.20%	0.60%
Retail & other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 0	$ 4
% to Non Accrual Total	0.00%	0.00%
Commercial Portfolio Segment | Commercial & industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 2,816	$ 6,016
% to Non Accrual Total	52.00%	46.00%
Commercial Portfolio Segment | Owner-occupied commercial real estate (“CRE”)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 673	$ 533
% to Non Accrual Total	12.00%	4.00%
Commercial Portfolio Segment | Agricultural (“AG”) production
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 0	$ 0
% to Non Accrual Total	0.00%	0.00%
Commercial Real Estate Portfolio Segment | AG real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 164	$ 186
% to Non Accrual Total	3.00%	1.00%
Commercial Real Estate Portfolio Segment | CRE investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 210	$ 4,531
% to Non Accrual Total	4.00%	35.00%
Commercial Real Estate Portfolio Segment | Construction & land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 80	$ 0
% to Non Accrual Total	1.00%	0.00%
Residential | Residential first mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 1,265	$ 1,587
% to Non Accrual Total	23.00%	12.00%
Residential | Residential junior mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 262	$ 158
% to Non Accrual Total	5.00%	1.00%
Residential | Residential construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 1	$ 80
% to Non Accrual Total	0.00%	1.00%
Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 1,409	$ 3,278
% to Non Accrual Total	100.00%	100.00%
Percent of nonaccrual loans	25.80%	25.00%
Originated | Retail & other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 0	$ 4
% to Non Accrual Total	0.00%	0.00%
Originated | Commercial Portfolio Segment | Commercial & industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 352	$ 2,296
% to Non Accrual Total	25.00%	70.00%
Originated | Commercial Portfolio Segment | Owner-occupied commercial real estate (“CRE”)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 362	$ 86
% to Non Accrual Total	26.00%	3.00%
Originated | Commercial Portfolio Segment | Agricultural (“AG”) production
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 0	$ 0
% to Non Accrual Total	0.00%	0.00%
Originated | Commercial Real Estate Portfolio Segment | AG real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 0	$ 0
% to Non Accrual Total	0.00%	0.00%
Originated | Commercial Real Estate Portfolio Segment | CRE investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 0	$ 549
% to Non Accrual Total	0.00%	17.00%
Originated | Commercial Real Estate Portfolio Segment | Construction & land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 0	$ 0
% to Non Accrual Total	0.00%	0.00%
Originated | Residential | Residential first mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 629	$ 331
% to Non Accrual Total	45.00%	10.00%
Originated | Residential | Residential junior mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 65	$ 12
% to Non Accrual Total	4.00%	0.00%
Originated | Residential | Residential construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 1	$ 0
% to Non Accrual Total	0.00%	0.00%
Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 4,062	$ 9,817
% to Non Accrual Total	100.00%	100.00%
Percent of nonaccrual loans	74.20%	75.00%
Acquired | Retail & other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 0	$ 0
% to Non Accrual Total	0.00%	0.00%
Acquired | Commercial Portfolio Segment | Commercial & industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 2,464	$ 3,720
% to Non Accrual Total	61.00%	38.00%
Acquired | Commercial Portfolio Segment | Owner-occupied commercial real estate (“CRE”)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 311	$ 447
% to Non Accrual Total	8.00%	4.00%
Acquired | Commercial Portfolio Segment | Agricultural (“AG”) production
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 0	$ 0
% to Non Accrual Total	0.00%	0.00%
Acquired | Commercial Real Estate Portfolio Segment | AG real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 164	$ 186
% to Non Accrual Total	4.00%	2.00%
Acquired | Commercial Real Estate Portfolio Segment | CRE investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 210	$ 3,982
% to Non Accrual Total	5.00%	41.00%
Acquired | Commercial Real Estate Portfolio Segment | Construction & land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 80	$ 0
% to Non Accrual Total	2.00%	0.00%
Acquired | Residential | Residential first mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 636	$ 1,256
% to Non Accrual Total	15.00%	13.00%
Acquired | Residential | Residential junior mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 197	$ 146
% to Non Accrual Total	5.00%	1.00%
Acquired | Residential | Residential construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	$ 0	$ 80
% to Non Accrual Total	0.00%	1.00%

LOANS, ALLOWANCE FOR LOAN LOS_8

LOANS, ALLOWANCE FOR LOAN LOSSES, AND CREDIT QUALITY - Summary of loans by past due status (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	$ 2,159,139	$ 2,072,198
Amount	$ 2,166,181	$ 2,087,925
Current - As a percent of total loans	99.70%	99.30%
As a percent of total loans	100.00%	100.00%
30-89 Days Past Due (accruing)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	$ 1,571	$ 2,632
Finance Receivables 30 To 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Percent Past Due	0.10%	0.10%
90 Days & Over or nonaccrual
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	$ 5,471	$ 13,095
Financing Receivable, Percent Past Due	0.20%	0.60%
Owner-occupied commercial real estate (“CRE”)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 441,353	$ 430,043
Retail & other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	26,483	22,807
Amount	26,493	22,815
Retail & other | 30-89 Days Past Due (accruing)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	10	4
Retail & other | 90 Days & Over or nonaccrual
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	4
Commercial Portfolio Segment | Commercial & industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	682,104	631,110
Amount	684,920	637,337
Commercial Portfolio Segment | Commercial & industrial | 30-89 Days Past Due (accruing)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	211
Commercial Portfolio Segment | Commercial & industrial | 90 Days & Over or nonaccrual
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	2,816	6,016
Commercial Portfolio Segment | Owner-occupied commercial real estate (“CRE”)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	440,123	428,839
Amount	441,353	430,043
Commercial Portfolio Segment | Owner-occupied commercial real estate (“CRE”) | 30-89 Days Past Due (accruing)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	557	671
Commercial Portfolio Segment | Owner-occupied commercial real estate (“CRE”) | 90 Days & Over or nonaccrual
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	673	533
Commercial Portfolio Segment | Agricultural (“AG”) production
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	35,606	35,425
Amount	35,625	35,455
Commercial Portfolio Segment | Agricultural (“AG”) production | 30-89 Days Past Due (accruing)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	19	30
Commercial Portfolio Segment | Agricultural (“AG”) production | 90 Days & Over or nonaccrual
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
Commercial Real Estate Portfolio Segment | AG real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	53,245	51,592
Amount	53,444	51,778
Commercial Real Estate Portfolio Segment | AG real estate | 30-89 Days Past Due (accruing)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	35	0
Commercial Real Estate Portfolio Segment | AG real estate | 90 Days & Over or nonaccrual
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	164	186
Commercial Real Estate Portfolio Segment | CRE investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	343,262	309,932
Amount	343,652	314,463
Commercial Real Estate Portfolio Segment | CRE investment | 30-89 Days Past Due (accruing)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	180	0
Commercial Real Estate Portfolio Segment | CRE investment | 90 Days & Over or nonaccrual
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	210	4,531
Commercial Real Estate Portfolio Segment | Construction & land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	80,519	89,584
Amount	80,599	89,660
Commercial Real Estate Portfolio Segment | Construction & land development | 30-89 Days Past Due (accruing)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	76
Commercial Real Estate Portfolio Segment | Construction & land development | 90 Days & Over or nonaccrual
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	80	0
Residential | Residential first mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	355,818	360,726
Amount	357,841	363,352
Residential | Residential first mortgage | 30-89 Days Past Due (accruing)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	758	1,039
Residential | Residential first mortgage | 90 Days & Over or nonaccrual
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	1,265	1,587
Residential | Residential junior mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	111,054	105,855
Amount	111,328	106,027
Residential | Residential junior mortgage | 30-89 Days Past Due (accruing)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	12	14
Residential | Residential junior mortgage | 90 Days & Over or nonaccrual
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	262	158
Residential | Residential construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current	30,925	36,328
Amount	30,926	36,995
Residential | Residential construction | 30-89 Days Past Due (accruing)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	587
Residential | Residential construction | 90 Days & Over or nonaccrual
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	1	80
Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	1,485,165	1,243,702
Originated | Retail & other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	23,809	18,254
Originated | Commercial Portfolio Segment | Commercial & industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	568,100	488,600
Originated | Commercial Portfolio Segment | Owner-occupied commercial real estate (“CRE”)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	283,531	237,548
Originated | Commercial Portfolio Segment | Agricultural (“AG”) production
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	11,113	11,102
Originated | Commercial Real Estate Portfolio Segment | AG real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	31,374	27,831
Originated | Commercial Real Estate Portfolio Segment | CRE investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	171,087	113,862
Originated | Commercial Real Estate Portfolio Segment | Construction & land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	66,478	56,061
Originated | Residential | Residential first mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	220,368	191,186
Originated | Residential | Residential junior mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	78,379	65,643
Originated | Residential | Residential construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	30,926	33,615
Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	681,016	844,223
Acquired | Owner-occupied commercial real estate (“CRE”)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount		192,495
Acquired | Retail & other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	2,684	4,561
Acquired | Commercial Portfolio Segment | Commercial & industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	116,820	148,737
Acquired | Commercial Portfolio Segment | Owner-occupied commercial real estate (“CRE”)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	157,822	192,495
Acquired | Commercial Portfolio Segment | Agricultural (“AG”) production
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	24,512	24,353
Acquired | Commercial Real Estate Portfolio Segment | AG real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	22,070	23,947
Acquired | Commercial Real Estate Portfolio Segment | CRE investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	172,565	200,601
Acquired | Commercial Real Estate Portfolio Segment | Construction & land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	14,121	33,599
Acquired | Residential | Residential first mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	137,473	172,166
Acquired | Residential | Residential junior mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	32,949	40,384
Acquired | Residential | Residential construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 0	$ 3,380

LOANS, ALLOWANCE FOR LOAN LOS_9

LOANS, ALLOWANCE FOR LOAN LOSSES, AND CREDIT QUALITY - Summary of loans by credit quality indicator based on internally assigned credit grade (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 2,166,181	$ 2,087,925
Percent of total	100.00%	100.00%
Grades 1- 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 2,061,424	$ 1,979,429
Percent of total	95.10%	94.80%
Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 58,822	$ 58,354
Percent of total	2.70%	2.80%
Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 18,607	$ 23,461
Percent of total	0.90%	1.10%
Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 27,328	$ 26,681
Percent of total	1.30%	1.30%
Grade 8
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 0	$ 0
Percent of total	0.00%	0.00%
Grade 9
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 0	$ 0
Percent of total	0.00%	0.00%
Retail & other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 26,493	$ 22,815
Retail & other | Grades 1- 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	26,493	22,811
Retail & other | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	0
Retail & other | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	0
Retail & other | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	4
Retail & other | Grade 8
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	0
Retail & other | Grade 9
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	0
Commercial Portfolio Segment | Commercial & industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	684,920	637,337
Commercial Portfolio Segment | Commercial & industrial | Grades 1- 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	649,475	597,854
Commercial Portfolio Segment | Commercial & industrial | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	16,145	12,999
Commercial Portfolio Segment | Commercial & industrial | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	6,178	16,129
Commercial Portfolio Segment | Commercial & industrial | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	13,122	10,355
Commercial Portfolio Segment | Commercial & industrial | Grade 8
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	0
Commercial Portfolio Segment | Commercial & industrial | Grade 9
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	0
Commercial Portfolio Segment | Owner-occupied CRE
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	441,353	430,043
Commercial Portfolio Segment | Owner-occupied CRE | Grades 1- 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	405,198	397,357
Commercial Portfolio Segment | Owner-occupied CRE | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	22,776	23,340
Commercial Portfolio Segment | Owner-occupied CRE | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	6,569	6,442
Commercial Portfolio Segment | Owner-occupied CRE | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	6,810	2,904
Commercial Portfolio Segment | Owner-occupied CRE | Grade 8
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	0
Commercial Portfolio Segment | Owner-occupied CRE | Grade 9
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	0
Commercial Portfolio Segment | Agricultural (“AG”) production
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	35,625	35,455
Commercial Portfolio Segment | Agricultural (“AG”) production | Grades 1- 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	29,363	30,431
Commercial Portfolio Segment | Agricultural (“AG”) production | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	3,302	4,000
Commercial Portfolio Segment | Agricultural (“AG”) production | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	2,351	0
Commercial Portfolio Segment | Agricultural (“AG”) production | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	609	1,024
Commercial Portfolio Segment | Agricultural (“AG”) production | Grade 8
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	0
Commercial Portfolio Segment | Agricultural (“AG”) production | Grade 9
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	0
Commercial Real Estate Portfolio Segment | AG real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	53,444	51,778
Commercial Real Estate Portfolio Segment | AG real estate | Grades 1- 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	46,248	44,321
Commercial Real Estate Portfolio Segment | AG real estate | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	3,246	4,873
Commercial Real Estate Portfolio Segment | AG real estate | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	2,983	0
Commercial Real Estate Portfolio Segment | AG real estate | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	967	2,584
Commercial Real Estate Portfolio Segment | AG real estate | Grade 8
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	0
Commercial Real Estate Portfolio Segment | AG real estate | Grade 9
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	0
Commercial Real Estate Portfolio Segment | CRE investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	343,652	314,463
Commercial Real Estate Portfolio Segment | CRE investment | Grades 1- 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	334,080	299,926
Commercial Real Estate Portfolio Segment | CRE investment | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	6,792	8,399
Commercial Real Estate Portfolio Segment | CRE investment | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	190
Commercial Real Estate Portfolio Segment | CRE investment | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	2,780	5,948
Commercial Real Estate Portfolio Segment | CRE investment | Grade 8
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	0
Commercial Real Estate Portfolio Segment | CRE investment | Grade 9
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	0
Commercial Real Estate Portfolio Segment | Construction & land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	80,599	89,660
Commercial Real Estate Portfolio Segment | Construction & land development | Grades 1- 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	75,365	86,011
Commercial Real Estate Portfolio Segment | Construction & land development | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	5,138	2,758
Commercial Real Estate Portfolio Segment | Construction & land development | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	16	17
Commercial Real Estate Portfolio Segment | Construction & land development | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	80	874
Commercial Real Estate Portfolio Segment | Construction & land development | Grade 8
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	0
Commercial Real Estate Portfolio Segment | Construction & land development | Grade 9
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	0
Residential | Residential first mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	357,841	363,352
Residential | Residential first mortgage | Grades 1- 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	353,239	358,067
Residential | Residential first mortgage | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	1,406	1,868
Residential | Residential first mortgage | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	510	683
Residential | Residential first mortgage | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	2,686	2,734
Residential | Residential first mortgage | Grade 8
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	0
Residential | Residential first mortgage | Grade 9
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	0
Residential | Residential junior mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	111,328	106,027
Residential | Residential junior mortgage | Grades 1- 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	111,037	105,736
Residential | Residential junior mortgage | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	17	117
Residential | Residential junior mortgage | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	0
Residential | Residential junior mortgage | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	274	174
Residential | Residential junior mortgage | Grade 8
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	0
Residential | Residential junior mortgage | Grade 9
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	0
Residential | Residential construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	30,926	36,995
Residential | Residential construction | Grades 1- 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	30,926	36,915
Residential | Residential construction | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	0
Residential | Residential construction | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	0
Residential | Residential construction | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	80
Residential | Residential construction | Grade 8
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	0	0
Residential | Residential construction | Grade 9
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount	$ 0	$ 0

LOANS, ALLOWANCE FOR LOAN LO_10

LOANS, ALLOWANCE FOR LOAN LOSSES, AND CREDIT QUALITY - Summary of information pertaining to impaired loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Impaired Financing Receivable, with No Realted Allowance
Recorded Investment	$ 9,939
Unpaid Principal Balance	16,021
Related Allowance	0
Average Recorded Investment	10,699
Interest Income Recognized	1,199
Impaired Financing Receivable
Recorded Investment	9,939	$ 17,221
Unpaid Principal Balance	16,021	26,948
Related Allowance	0	163
Average Recorded Investment	10,699	16,810
Interest Income Recognized	1,199	1,623
Retail & other
Impaired Financing Receivable, with No Realted Allowance
Recorded Investment	12
Unpaid Principal Balance	12
Related Allowance	0
Average Recorded Investment	12
Interest Income Recognized	1
Commercial Portfolio Segment | Commercial & industrial
Impaired Financing Receivable, with No Realted Allowance
Recorded Investment	2,927
Unpaid Principal Balance	6,736
Related Allowance	0
Average Recorded Investment	4,041
Interest Income Recognized	660
Commercial Portfolio Segment | Owner-occupied commercial real estate (“CRE”)
Impaired Financing Receivable, with No Realted Allowance
Recorded Investment	1,506
Unpaid Principal Balance	1,833
Related Allowance	0
Average Recorded Investment	1,659
Interest Income Recognized	137
Commercial Portfolio Segment | Agricultural (“AG”) production
Impaired Financing Receivable, with No Realted Allowance
Recorded Investment	0
Unpaid Principal Balance	0
Related Allowance	0
Average Recorded Investment	0
Interest Income Recognized	0
Commercial Real Estate Portfolio Segment | AG real estate
Impaired Financing Receivable, with No Realted Allowance
Recorded Investment	222
Unpaid Principal Balance	281
Related Allowance	0
Average Recorded Investment	238
Interest Income Recognized	26
Commercial Real Estate Portfolio Segment | CRE investment
Impaired Financing Receivable, with No Realted Allowance
Recorded Investment	1,686
Unpaid Principal Balance	2,484
Related Allowance	0
Average Recorded Investment	1,606
Interest Income Recognized	163
Commercial Real Estate Portfolio Segment | Construction & land development
Impaired Financing Receivable, with No Realted Allowance
Recorded Investment	603
Unpaid Principal Balance	1,506
Related Allowance	0
Average Recorded Investment	603
Interest Income Recognized	21
Residential | Residential first mortgage
Impaired Financing Receivable, with No Realted Allowance
Recorded Investment	2,750
Unpaid Principal Balance	2,907
Related Allowance	0
Average Recorded Investment	2,478
Interest Income Recognized	176
Residential | Residential junior mortgage
Impaired Financing Receivable, with No Realted Allowance
Recorded Investment	233
Unpaid Principal Balance	262
Related Allowance	0
Average Recorded Investment	62
Interest Income Recognized	15
Residential | Residential construction
Impaired Financing Receivable, with No Realted Allowance
Recorded Investment	0
Unpaid Principal Balance	0
Related Allowance	0
Average Recorded Investment	0
Interest Income Recognized	0
Originated
Impaired Financing Receivable
Recorded Investment	548	3,003
Unpaid Principal Balance	548	3,003
Related Allowance	0	163
Average Recorded Investment	899	2,964
Interest Income Recognized	154	241
Acquired
Impaired Financing Receivable, with No Realted Allowance
Recorded Investment		17,221
Unpaid Principal Balance		26,948
Related Allowance		163
Average Recorded Investment		16,810
Interest Income Recognized		1,623
Impaired Financing Receivable
Recorded Investment	9,391	14,218
Unpaid Principal Balance	15,473	23,945
Related Allowance	0	0
Average Recorded Investment	9,800	13,846
Interest Income Recognized	$ 1,045	1,382
Acquired | Retail & other
Impaired Financing Receivable, with No Realted Allowance
Recorded Investment		12
Unpaid Principal Balance		14
Related Allowance		0
Average Recorded Investment		12
Interest Income Recognized		1
Acquired | Commercial Portfolio Segment | Commercial & industrial
Impaired Financing Receivable, with No Realted Allowance
Recorded Investment		5,870
Unpaid Principal Balance		10,063
Related Allowance		163
Average Recorded Investment		6,586
Interest Income Recognized		718
Acquired | Commercial Portfolio Segment | Owner-occupied commercial real estate (“CRE”)
Impaired Financing Receivable, with No Realted Allowance
Recorded Investment		1,689
Unpaid Principal Balance		2,256
Related Allowance		0
Average Recorded Investment		1,333
Interest Income Recognized		132
Acquired | Commercial Portfolio Segment | Agricultural (“AG”) production
Impaired Financing Receivable, with No Realted Allowance
Recorded Investment		0
Unpaid Principal Balance		10
Related Allowance		0
Average Recorded Investment		0
Interest Income Recognized		0
Acquired | Commercial Real Estate Portfolio Segment | AG real estate
Impaired Financing Receivable, with No Realted Allowance
Recorded Investment		248
Unpaid Principal Balance		307
Related Allowance		0
Average Recorded Investment		233
Interest Income Recognized		26
Acquired | Commercial Real Estate Portfolio Segment | CRE investment
Impaired Financing Receivable, with No Realted Allowance
Recorded Investment		5,290
Unpaid Principal Balance		8,102
Related Allowance		0
Average Recorded Investment		5,411
Interest Income Recognized		465
Acquired | Commercial Real Estate Portfolio Segment | Construction & land development
Impaired Financing Receivable, with No Realted Allowance
Recorded Investment		1,053
Unpaid Principal Balance		1,053
Related Allowance		0
Average Recorded Investment		813
Interest Income Recognized		57
Acquired | Residential | Residential first mortgage
Impaired Financing Receivable, with No Realted Allowance
Recorded Investment		2,801
Unpaid Principal Balance		3,653
Related Allowance		0
Average Recorded Investment		2,177
Interest Income Recognized		180
Acquired | Residential | Residential junior mortgage
Impaired Financing Receivable, with No Realted Allowance
Recorded Investment		178
Unpaid Principal Balance		507
Related Allowance		0
Average Recorded Investment		154
Interest Income Recognized		17
Acquired | Residential | Residential construction
Impaired Financing Receivable, with No Realted Allowance
Recorded Investment		80
Unpaid Principal Balance		983
Related Allowance		0
Average Recorded Investment		91
Interest Income Recognized		$ 27

LOANS, ALLOWANCE FOR LOAN LO_11

LOANS, ALLOWANCE FOR LOAN LOSSES, AND CREDIT QUALITY - Summary of Non-accredtable discount on purchase credit impaired ("PCI") loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Accretion Discount [Roll Forward]
Balance at beginning of period	$ 9,471	$ 14,327
Acquired balance, net	0	8,352
Accretion to loan interest income	(1,976)	(7,995)
Transferred to accretable	(990)	(1,936)
Disposals of loans	(97)	(3,277)
Balance at end of period	$ 6,408	$ 9,471

PREMISES AND EQUIPMENT - Narrat

PREMISES AND EQUIPMENT - Narrative (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Depreciation expense		$ 4.4	$ 4.2	$ 3.2
Rent expense		$ 1.4	$ 1.1	$ 0.8
Lease termination liability	$ 1.7

PREMISES AND EQUIPMENT - Summar

PREMISES AND EQUIPMENT - Summary of premises and equipment, less accumulated depreciation (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 74,982	$ 69,673
Less accumulated depreciation and amortization	26,809	22,522
Premises and equipment, net	48,173	47,151
Land
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	6,220	5,987
Land improvements
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	3,842	3,591
Building and improvements
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	42,238	39,661
Leasehold improvements
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	4,092	4,092
Furniture and equipment
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 18,590	$ 16,342

PREMISES AND EQUIPMENT - Minimu

PREMISES AND EQUIPMENT - Minimum annual rentals under these noncancelable agreements with remaining terms in excess of one year (Details) $ in Thousands	Dec. 31, 2018USD ($)
Property, Plant and Equipment [Abstract]
2,019	$ 1,073
2,020	1,065
2,021	956
2,022	902
2,023	665
Thereafter	742
Total	$ 5,403

GOODWILL AND OTHER INTANGIBLE_3

GOODWILL AND OTHER INTANGIBLES AND MORTGAGE SERVICING RIGHTS - Narrative (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Apr. 29, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$ 107,366	$ 107,366	$ 66,000

GOODWILL AND OTHER INTANGIBLE_4

GOODWILL AND OTHER INTANGIBLES AND MORTGAGE SERVICING RIGHTS - Summary of Goodwill and Other Intangibles (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Apr. 29, 2016
Goodwill And Intangible Assets And Mortgage Servicing Rights [Line Items]
Goodwill	$ 107,366	$ 107,366	$ 66,000
Goodwill and other intangibles, net	124,307	128,406
Core deposit intangibles
Goodwill And Intangible Assets And Mortgage Servicing Rights [Line Items]
Other intangibles	12,562	16,477
Customer list intangibles:
Goodwill And Intangible Assets And Mortgage Servicing Rights [Line Items]
Other intangibles	4,379	4,563
Other intangibles
Goodwill And Intangible Assets And Mortgage Servicing Rights [Line Items]
Other intangibles	$ 16,941	$ 21,040

GOODWILL AND OTHER INTANGIBLE_5

GOODWILL AND OTHER INTANGIBLES AND MORTGAGE SERVICING RIGHTS - Other Intangibles (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Amortization during the period	$ 4,389	$ 4,695	$ 3,458
Core deposit intangibles:
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	29,015	29,015
Accumulated amortization	(16,453)	(12,538)
Net book value	12,562	16,477
Additions during the period	0	3,670
Amortization during the period	3,915	4,294
Customer list intangibles:
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	5,523	5,233
Accumulated amortization	(1,144)	(670)
Net book value	4,379	4,563
Additions during the period	290	870
Amortization during the period	$ 474	$ 401

GOODWILL AND OTHER INTANGIBLE_6

GOODWILL AND OTHER INTANGIBLES AND MORTGAGE SERVICING RIGHTS (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
MSR Asset
MSR asset at beginning of year	$ 3,187
MSR asset at end of year	3,749	$ 3,187
Mortgage Servicing Rights
MSR Asset
MSR asset at beginning of year	3,187	1,922
Capitalized MSR	1,203	876
MSR asset acquired	0	874
Amortization during the period	(641)	(485)
MSR asset at end of year	3,749	3,187
Fair value of MSR asset at end of period	6,347	4,097
Residential mortgage loans serviced for others	$ 603,446	$ 518,419
Net Book Value Of Msr Asset To Loans Serviced For Others	0.62%	0.61%

GOODWILL AND OTHER INTANGIBLE_7

GOODWILL AND OTHER INTANGIBLES AND MORTGAGE SERVICING RIGHTS (Details 3) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
MSR asset
2,019	$ 697
2,020	680
2,021	531
2,022	531
2,023	419
Thereafter	891
Total	3,749	$ 3,187
Core deposit intangibles
Core Deposit and Customer List Intangibles
2,019	3,337
2,020	2,657
2,021	2,167
2,022	1,735
2,023	1,273
Thereafter	1,393
Net book value	12,562	16,477
Customer list intangibles:
Core Deposit and Customer List Intangibles
2,019	507
2,020	507
2,021	507
2,022	507
2,023	483
Thereafter	1,868
Net book value	$ 4,379	$ 4,563

OTHER REAL ESTATE OWNED - Summa

OTHER REAL ESTATE OWNED - Summary of other real estate owned net of valuation allowances (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Other Real Estate [Roll Forward]
Balance at beginning of period	$ 1,294	$ 2,059
Additions for new construction	607	583
Sales proceeds	(2,824)	(1,724)
Net gain from sales	1,032	258	$ 666
Write-downs	(120)	(127)
Additions for new construction	431	0
Acquired balance, net	0	245
Balance at end of period	$ 420	$ 1,294	$ 2,059

DEPOSITS - Narrative (Details)

DEPOSITS - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Deposits [Abstract]
Aggregate amount of time deposits with minimum denomination of $250,000	$ 77.6	$ 50.4

DEPOSITS - Maturities of time d

DEPOSITS - Maturities of time deposits (Details) $ in Thousands	Dec. 31, 2018USD ($)
Deposits [Abstract]
2,019	$ 260,993
2,020	89,948
2,021	22,847
2,022	14,760
2,023	15,088
Thereafter	0
Total time deposits	$ 403,636

SHORT AND LONG-TERM BORROWING_2

SHORT AND LONG-TERM BORROWINGS - Narrative (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2015	Dec. 31, 2017
Debt Type [Line Items]
Trust preferred securities qualify as Tier 1 capital	$ 28,900,000		$ 28,500,000
Par	$ 38,249,000
FHLB advances
Debt Type [Line Items]
Weighted average rate of FHLB advances	1.72%		1.71%
FHLB advances collateralized pledged	$ 295,300,000		$ 313,500,000
Subordinated Notes
Debt Type [Line Items]
Par		$ 12,000,000
Subordinated notes, maturity period		10 years
Fixed interest rate on subordinated notes		5.00%
Nicolet Bankshares, Inc | Letter of Credit
Debt Type [Line Items]
Line of credit with third party bank	$ 10,000,000
Basis spread rate	2.25%
Floor rate	3.25%
Long-term line of credit outstanding	$ 0		$ 0

SHORT AND LONG-TERM BORROWING_3

SHORT AND LONG-TERM BORROWINGS - Long-term debt instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Long-term borrowings	$ 77,305	$ 78,046
FHLB advances
Debt Instrument [Line Items]
Long-term borrowings	35,252	36,509
Junior subordinated debentures
Debt Instrument [Line Items]
Subordinated notes	30,096	29,616
Subordinated notes
Debt Instrument [Line Items]
Subordinated notes	$ 11,957	$ 11,921

SHORT AND LONG-TERM BORROWING_4

SHORT AND LONG-TERM BORROWINGS - Summary of maturity of notes payable (Details) - FHLB advances $ in Thousands	Dec. 31, 2018USD ($)
Debt Instrument [Line Items]
2,019	$ 0
2,020	10,000
2,021	0
2,022	25,252
2,023	0
Advances from Federal Home Loan Banks	$ 35,252

SHORT AND LONG-TERM BORROWING_5

SHORT AND LONG-TERM BORROWINGS - Junior Subordinated Debentures (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Par	$ 38,249,000
Unamortized discount	(8,153,000)
Carrying Value	30,096,000	$ 29,616,000
2005 Mid-Wisconsin Financial Services, Inc.
Debt Instrument [Line Items]
Par	10,310,000
Unamortized discount	(3,371,000)
Carrying Value	$ 6,939,000	$ 6,739,000
Interest rate	4.22%	3.02%
2006 Baylake Corp.
Debt Instrument [Line Items]
Par	$ 16,598,000
Unamortized discount	(4,120,000)
Carrying Value	$ 12,478,000	$ 12,242,000
Interest rate	4.15%	3.04%
2004 First Menasha Bancshares, Inc.
Debt Instrument [Line Items]
Par	$ 5,155,000
Unamortized discount	(662,000)
Carrying Value	$ 4,493,000	$ 4,449,000
Interest rate	5.58%	4.39%
2004 Nicolet Bankshares Statutory Trust
Debt Instrument [Line Items]
Par	$ 6,186,000
Unamortized discount	0
Carrying Value	$ 6,186,000	$ 6,186,000
Interest rate	8.00%
London Interbank Offered Rate (LIBOR) | 2005 Mid-Wisconsin Financial Services, Inc.
Debt Instrument [Line Items]
Basis spread rate	1.43%
London Interbank Offered Rate (LIBOR) | 2006 Baylake Corp.
Debt Instrument [Line Items]
Basis spread rate	1.35%
London Interbank Offered Rate (LIBOR) | 2004 First Menasha Bancshares, Inc.
Debt Instrument [Line Items]
Basis spread rate	2.79%

EMPLOYEE AND DIRECTOR BENEFIT_2

EMPLOYEE AND DIRECTOR BENEFIT PLANS - Narrative (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)Planshares	Dec. 31, 2017USD ($)shares	Dec. 31, 2016USD ($)
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of deferred compensation plans | Plan	2
Employees contribution	100.00%
Employer contribution matching percent	100.00%
Percentage of employee's gross pay	6.00%
Vesting period	5 years
Company 401k expense	$ 1,800	$ 2,000	$ 1,200
Profit sharing contribution		500
Deferred compensation plan | Key Management Employees | Other liabilities
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Liability for cumulative employee contributions and earnings	527	152
Non elective contributions to selected recipients	$ 175	$ 700
Deferred compensation plan | Director
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Maximum percentage to defer the compensation under the plan	100.00%
Number of shares purchased under deferred compensation plan | shares	3,889	4,427
Value of shares purchased under deferred compensation plan	$ 213	$ 229
Value of shares distributed under director plan	$ 32	$ 473
Number of shares distributed under director plan | shares	600	9,900
Deferred compensation liability offsetting equity component	$ 831	$ 636
Deferred compensation liability offsetting equity component (in shares) | shares	26,070	22,853
Minimum | Deferred compensation plan | Key Management Employees | Other liabilities
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting period from date of grant	4 years
Maximum | Deferred compensation plan | Key Management Employees | Other liabilities
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting period from date of grant	5 years

STOCK-BASED COMPENSATION - Narr

STOCK-BASED COMPENSATION - Narrative (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period of options	10 years
Number of shares surrendered (in shares)	6,411	85,422	10,244
Numbers of shares surrendered (in shares)	3,948	5,266	7,851
Stock based compensation expense	$ 4.7	$ 3.1	$ 1.6
Unrecognized compensation cost	$ 12.9
Remaining vesting period over which cost expected to be recognized	3 years
Stock based compensation tax benefit	$ 0.2	1.9
2011 Long Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares initially covered under the plan	1,500,000
Number of shares were available for grant	127,000
2002 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares initially covered under the plan	1,175,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total intrinsic value of options exercised	$ 2.2	$ 7.5	$ 1.3
Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense	$ 0.2
Restricted stock grant	3,510

STOCK-BASED COMPENSATION - Summ

STOCK-BASED COMPENSATION - Summery weighted average assumptions (Details) - Stock Incentive Plan - Stock Options - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	0.00%	0.00%	0.00%
Expected volatility	25.00%	25.00%	25.00%
Risk-free interest rate	2.60%	2.10%	1.50%
Expected average life	7 years	7 years	7 years
Weighted average per share fair value of options	$ 17.36	$ 15.80	$ 11.04

STOCK-BASED COMPENSATION- Activ

STOCK-BASED COMPENSATION- Activity of stock incentive plans for options (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Options Shares Outstanding
Forfeited	(6,411)	(85,422)	(10,244)
Stock Incentive Plan | Stock Options
Options Shares Outstanding
Outstanding, beginning of period	1,643,255	922,026	746,004
Granted	15,500	949,500	170,500
Options assumed in acquisition			91,701
Exercise of stock options	(70,556)	(209,371)	(84,723)
Forfeited	(6,500)	(18,900)	(1,456)
Outstanding, ending of period	1,581,699	1,643,255	922,026
Exercisable	599,011
Weighted-Average Exercise Price
Outstanding	$ 39.82	$ 24.39	$ 21.56
Granted	52.76	49.93	36.86
Options assumed in acquisition			21.03
Exercise of stock options	21.52	18.15	20.98
Forfeited	39.43	35.36	21.71
Outstanding	40.77	$ 39.82	$ 24.39
Exercisable Shares	$ 32.77
Outstanding Shares, Weighted Average Remaining Life (in years)	7 years 4 months 17 days	8 years 1 month 6 days	5 years 4 months 13 days
Exercisable Shares, Weighted Average Remaining Life (in years)	6 years 3 months 14 days
Outstanding Shares, Aggregate Intrinsic Value	$ 13,825	$ 24,525	$ 21,483
Exercisable Shares, Aggregate Intrinsic Value	$ 9,798

STOCK-BASED COMPENSATION - Sche

STOCK-BASED COMPENSATION - Schedule of options outstanding (Details)	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Shares Outstanding | shares	1,581,699
Number of Shares Exercisable | shares	599,011
Weighted-Average Exercise Price Outstanding	$ 40.77
Weighted-Average Exercise Price Exercisable	$ 32.77
Weighted-Average Remaining Life (Years) Outstanding	7 years 4 months 17 days
Weighted-Average Remaining Life (Years) Exercisable	6 years 3 months 14 days
Exercise Price $9.19 - $20.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Shares Outstanding | shares	99,267
Number of Shares Exercisable | shares	85,579
Weighted-Average Exercise Price Outstanding	$ 16.39
Weighted-Average Exercise Price Exercisable	$ 16.38
Weighted-Average Remaining Life (Years) Outstanding	1 year 11 months 19 days
Weighted-Average Remaining Life (Years) Exercisable	1 year 9 months 3 days
Exercise Price $20.01 - $25.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Shares Outstanding | shares	202,268
Number of Shares Exercisable | shares	160,468
Weighted-Average Exercise Price Outstanding	$ 23.77
Weighted-Average Exercise Price Exercisable	$ 23.77
Weighted-Average Remaining Life (Years) Outstanding	5 years 9 months 21 days
Weighted-Average Remaining Life (Years) Exercisable	5 years 9 months 21 days
Exercise Price $25.01 - $30.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Shares Outstanding | shares	142,294
Number of Shares Exercisable | shares	87,494
Weighted-Average Exercise Price Outstanding	$ 25.97
Weighted-Average Exercise Price Exercisable	$ 26.01
Weighted-Average Remaining Life (Years) Outstanding	6 years 25 days
Weighted-Average Remaining Life (Years) Exercisable	6 years 25 days
Exercise Price $30.01 - $40.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Shares Outstanding | shares	180,370
Number of Shares Exercisable | shares	77,070
Weighted-Average Exercise Price Outstanding	$ 35.95
Weighted-Average Exercise Price Exercisable	$ 35.41
Weighted-Average Remaining Life (Years) Outstanding	7 years 4 months 27 days
Weighted-Average Remaining Life (Years) Exercisable	7 years 3 months 7 days
Exercise Price $40.01- $56.43
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Shares Outstanding | shares	957,500
Number of Shares Exercisable | shares	188,400
Weighted-Average Exercise Price Outstanding	$ 49.99
Weighted-Average Exercise Price Exercisable	$ 49.94
Weighted-Average Remaining Life (Years) Outstanding	8 years 5 months 15 days
Weighted-Average Remaining Life (Years) Exercisable	8 years 5 months 8 days
Minimum | Exercise Price $9.19 - $20.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-Average Exercise Price Outstanding	$ 9.19
Weighted-Average Exercise Price Exercisable	9.19
Minimum | Exercise Price $20.01 - $25.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-Average Exercise Price Outstanding	20.01
Weighted-Average Exercise Price Exercisable	20.01
Minimum | Exercise Price $25.01 - $30.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-Average Exercise Price Outstanding	25.01
Weighted-Average Exercise Price Exercisable	25.01
Minimum | Exercise Price $30.01 - $40.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-Average Exercise Price Outstanding	30.01
Weighted-Average Exercise Price Exercisable	30.01
Minimum | Exercise Price $40.01- $56.43
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-Average Exercise Price Outstanding	40.01
Weighted-Average Exercise Price Exercisable	40.01
Maximum | Exercise Price $9.19 - $20.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-Average Exercise Price Outstanding	20
Weighted-Average Exercise Price Exercisable	20
Maximum | Exercise Price $20.01 - $25.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-Average Exercise Price Outstanding	25
Weighted-Average Exercise Price Exercisable	25
Maximum | Exercise Price $25.01 - $30.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-Average Exercise Price Outstanding	30
Weighted-Average Exercise Price Exercisable	30
Maximum | Exercise Price $30.01 - $40.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-Average Exercise Price Outstanding	40
Weighted-Average Exercise Price Exercisable	40
Maximum | Exercise Price $40.01- $56.43
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Weighted-Average Exercise Price Outstanding	56.43
Weighted-Average Exercise Price Exercisable	$ 56.43

STOCK-BASED COMPENSATION - Acti

STOCK-BASED COMPENSATION - Activity of restricted stock awards (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Weighted-Average Grant Date Fair Value
Forfeited	$ 16.50	$ 16.50	$ 0
Restricted Stock
Weighted-Average Grant Date Fair Value
Outstanding, beginning of period	34.26	26.80	18.70
Granted	52.55	57.75	33.68
Vested	43.58	29.87	23.58
Outstanding, end of period	$ 39.37	$ 34.26	$ 26.80
Stock Incentive Plan | Restricted Stock
Restricted Shares Outstanding
Outstanding, beginning of period	29,512	30,920	42,949	36,690
Granted	18,256	9,240	31,466
Vested	19,661	20,514	25,207
Forfeited	(3)	(755)	0
Outstanding, end of period	29,512	30,920	42,949

STOCKHOLDERS' EQUITY (Details)

STOCKHOLDERS' EQUITY (Details) - USD ($)	Apr. 28, 2017	Apr. 29, 2016	Apr. 01, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Stock Transaction [Line Items]
Cumulative amount repurchased				$ 46,300,000
Cumulative shares repurchased (in shares)				1,100,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount				$ 7,700,000
Common stock issued in acquisitions				0	$ 62,246,000	$ 165,295,000
Net cash received in business combinations				0	$ 9,119,000	$ 66,517,000
Financial Advisor
Stock Transaction [Line Items]
Common stock issued in acquisitions			$ 2,600,000
Merger Agreement | As recorded by Baylake Corp
Stock Transaction [Line Items]
Number of common stock issued for consideration		4,344,243
Common stock issued in acquisitions		$ 163,300,000
Additional consideration for assumed stock options		1,200,000
Costs incurred related to stock issuance		$ 300,000
Merger Agreement | First Menasha
Stock Transaction [Line Items]
Number of common stock issued for consideration	1,309,885
Common stock issued in acquisitions	$ 62,200,000
Net cash received in business combinations	19,300,000
Costs incurred related to stock issuance	$ 200,000
Common stock repurchase program
Stock Transaction [Line Items]
Value of shares authorized to repurchased				$ 54,000,000
Shares authorized to repurchased				1,450,000
Stock repurchased under plan				$ 22,200,000
Number of shares cancelled under plan (in shares)				408,100
Weighted average price of share cancelled				$ 54.35

INCOME TAXES - Narrative (Detai

INCOME TAXES - Narrative (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Loss Carryforwards [Line Items]
Adjustment to the net deferred tax asset for the Tax Cuts and Jobs Act	$ 0	$ 885,000	$ 0
Valuation allowance	$ 0	$ 0
Utilization period of operating loss carryforwards	14 years
Federal
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 4,200,000
State
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	21,000,000
State net operating loss carried regular operations	2,200,000
Mid-Wisconsin, Baylake, and First Menasha | Federal
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	4,200,000
Mid-Wisconsin, Baylake, and First Menasha | State
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 18,800,000

INCOME TAXES - Current and defe

INCOME TAXES - Current and deferred amounts of income tax expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Current	$ 14,967	$ 10,952	$ 12,708
Deferred	(1,521)	4,430	(3,337)
Adjustment to the net deferred tax asset for the Tax Cuts and Jobs Act	0	885	0
Income tax expense	$ 13,446	$ 16,267	$ 9,371

INCOME TAXES - Differences betw

INCOME TAXES - Differences between income tax expense recognized and amount computed by applying statutory federal income tax rate to earnings before income taxes, less noncontrolling interest (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Tax on pretax income, less noncontrolling interest, at statutory rates	$ 11,441	$ 17,296	$ 9,742
State income taxes, net of federal effect	3,308	2,242	1,339
Tax-exempt interest income	(574)	(1,073)	(769)
Non-deductible interest disallowance	30	28	18
Increase in cash surrender value life insurance	(508)	(807)	(452)
Non-deductible business entertainment	156	168	106
Non-deductible merger expenses	0	65	18
Stock-based employee compensation	(50)	(62)	(35)
Adjustment to the net deferred tax asset for the Tax Cuts and Jobs Act	0	885	0
Deduction attributable to share-based payments	0	(1,854)	0
Other, net	(357)	(621)	(596)
Income tax expense	$ 13,446	$ 16,267	$ 9,371

INCOME TAXES - Net deferred tax

INCOME TAXES - Net deferred tax asset includes amounts of deferred tax assets and liabilities (Details 2) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
ALLL	$ 5,240	$ 7,806
Net operating loss carryforwards	2,202	2,694
Credit carryforwards	43	1,433
Compensation	2,408	1,818
Other	2,549	1,379
Other real estate	103	0
Unrealized loss on securities AFS	1,740	794
Total deferred tax assets	14,285	15,924
Deferred tax liabilities:
Premises and equipment	(821)	(954)
Prepaid expenses	(693)	(728)
Investment securities	(1,723)	(1,589)
Core deposit and other intangibles	(3,563)	(4,101)
Estimated section 382 limitation	0	(543)
Purchase accounting adjustments to liabilities	(2,011)	(2,113)
Other	(1,021)	(868)
Total deferred tax liabilities	(9,832)	(10,896)
Net deferred tax assets	$ 4,453	$ 5,028

COMMITMENTS AND CONTINGENCIES_2

COMMITMENTS AND CONTINGENCIES (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments to sell residential mortgage loans held for sale considered derivative instruments	$ 18.2
Commitments to sell residential mortgage loans held for sale considered contractual amounts	$ 6
Commercial-related commitments to extend credit	77.00%	78.00%
Federal funds accommodations	$ 175	$ 158

COMMITMENTS AND CONTINGENCIES -

COMMITMENTS AND CONTINGENCIES - Contract or notional amount of exposure to off-balance-sheet risk (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Commitments to extend credit
Other Commitments [Line Items]
Contract and notional amounts of commitments	$ 721,098	$ 680,307
Financial standby letters of credit
Other Commitments [Line Items]
Contract and notional amounts of commitments	8,571	8,783
Performance standby letters of credit
Other Commitments [Line Items]
Contract and notional amounts of commitments	$ 7,094	$ 9,080

RELATED PARTY TRANSACTIONS (Det

RELATED PARTY TRANSACTIONS (Detail Textuals) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Related Party Transaction [Line Items]
Related party loans, total	$ 83,800	$ 67,700
Nicolet Joint Ventures, LLC (the "JV")
Related Party Transaction [Line Items]
Percentage of Nicolet National Bank	50.00%
Director | New branch location in facility opened in October 2013
Related Party Transaction [Line Items]
Payments for branch reconstruction	$ 956
Percentage payments for branch reconstruction paid to subcontractor	75.00%
Director | New branch location in facility opened in October 2013 | Maximum
Related Party Transaction [Line Items]
Rent expense	$ 120	120	$ 120
Management | Lease agreement for a non-branch location owned by a relative of a senior management team member and paid approximately
Related Party Transaction [Line Items]
Rent expense	138	138	100
Relative of the management
Related Party Transaction [Line Items]
Payment for services	657	668	420
Relative of the senior management team member
Related Party Transaction [Line Items]
Payment for services	284	257	400
Nicolet national bank | Nicolet Joint Ventures, LLC (the "JV")
Related Party Transaction [Line Items]
Rent expense	$ 1,100	$ 1,100	$ 1,100

ASSETS GAINS (LOSSES), NET - Co

ASSETS GAINS (LOSSES), NET - Components of gain (loss) on sale, disposals and writedown of assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Discontinued Operations and Disposal Groups [Abstract]
Gains (losses) on sales of securities AFS, net	$ (212)	$ 1,220	$ 78
Gains (losses) on equity securities, net	77	0	0
Gains on sales of OREO, net	1,032	258	666
Write-downs of OREO	(120)	(127)	0
Write-down of other investment	0	0	(500)
Gains (losses) on sales of other investments, net	187	0	0
Gains (losses) on sales or dispositions of other assets, net	205	678	(190)
Asset gains (losses), net	$ 1,169	$ 2,029	$ 54

REGULATORY CAPITAL REQUIREMEN_3

REGULATORY CAPITAL REQUIREMENTS - Company's and Bank's actual regulatory capital amounts and ratios (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Nicolet Bankshares, Inc
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total risk-based capital, Actual amount	$ 326,235	$ 299,043
Total risk-based capital, Actual ratio	12.90%	12.80%
Total risk-based capital, For capital adequacy purposes, Actual Amount	$ 202,836	$ 186,475
Total risk-based capital, For capital adequacy purposes, Actual Ratio	8.00%	8.00%
Tier I risk-based capital, Actual amount	$ 301,125	$ 274,469
Tier I risk-based capital, Actual ratio	11.90%	11.80%
Tier I risk-based capital, For capital adequacy purposes, Actual Amount	$ 152,127	$ 139,856
Tier I risk-based capital, For capital adequacy purposes, Actual Ratio	6.00%	6.00%
Common equity Tier 1 capital, Actual Amount	$ 271,435	$ 245,214
Common equity Tier 1 capital, Actual Ratio	10.70%	10.50%
Common equity Tier 1 capital, For Capital Adequacy Purposes, Actual Amount	$ 114,095	$ 104,892
Common equity Tier 1 capital, For Capital Adequacy Purposes, Actual Ratio	4.50%	4.50%
Leverage, Actual amount	$ 301,125	$ 274,469
Leverage, Actual ratio	10.40%	10.00%
Leverage, For capital adequacy purposes, Actual Amount	$ 115,483	$ 109,298
Leverage, For capital adequacy purposes, Actual Ratio	4.00%	4.00%
Nicolet national bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total risk-based capital, Actual amount	$ 274,492	$ 267,165
Total risk-based capital, Actual ratio	10.80%	11.50%
Total risk-based capital, For capital adequacy purposes, Actual Amount	$ 202,800	$ 186,606
Total risk-based capital, For capital adequacy purposes, Actual Ratio	8.00%	8.00%
Total risk-based capital, To be well capitalized under prompt corrective action provisions, Actual Amount	$ 253,501	$ 233,257
Total risk-based capital, To be well capitalized under prompt corrective action provisions, Actual Ratio	10.00%	10.00%
Tier I risk-based capital, Actual amount	$ 261,339	$ 254,512
Tier I risk-based capital, Actual ratio	10.30%	10.90%
Tier I risk-based capital, For capital adequacy purposes, Actual Amount	$ 152,100	$ 139,954
Tier I risk-based capital, For capital adequacy purposes, Actual Ratio	6.00%	6.00%
Tier I risk-based capital, To be well capitalized under prompt corrective action provisions, Actual Amount	$ 202,800	$ 186,606
Tier I risk-based capital, To be well capitalized under prompt corrective action provisions, Actual Ratio	8.00%	8.00%
Common equity Tier 1 capital, Actual Amount	$ 261,339	$ 254,512
Common equity Tier 1 capital, Actual Ratio	10.30%	10.90%
Common equity Tier 1 capital, For Capital Adequacy Purposes, Actual Amount	$ 114,075	$ 104,966
Common equity Tier 1 capital, For Capital Adequacy Purposes, Actual Ratio	4.50%	4.50%
Common equity Tier 1 capital, To Be Well Capitalized Under Prompt Corrective Action Provisions, Actual Amount	$ 164,775	$ 151,617
Common equity Tier 1 capital, To be well capitalized under prompt corrective action provisions ratio, Actual Ratio	6.50%	6.50%
Leverage, Actual amount	$ 261,339	$ 254,512
Leverage, Actual ratio	9.10%	9.30%
Leverage, For capital adequacy purposes, Actual Amount	$ 115,280	$ 109,226
Leverage, For capital adequacy purposes, Actual Ratio	4.00%	4.00%
Leverage, To be well capitalized under prompt corrective action provisions, Actual Amount	$ 144,100	$ 136,532
Leverage, To be well capitalized under prompt corrective action provisions, Actual Ratio	5.00%	5.00%

FAIR VALUE MEASUREMENTS - Measu

FAIR VALUE MEASUREMENTS - Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	$ 400,144	$ 405,153
Total
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	400,144	405,153
Level 1 | Total
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	0	2,571
Level 2 | Total
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	391,654	393,431
Level 3 | Total
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	8,490	9,151
Measured at Fair Value on a Recurring Basis | Total
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	400,144	405,153
Measured at Fair Value on a Recurring Basis | Total | U.S. government agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	21,649	26,209
Measured at Fair Value on a Recurring Basis | Total | State, county and municipals
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	160,526	184,044
Measured at Fair Value on a Recurring Basis | Total | Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	131,644	155,532
Measured at Fair Value on a Recurring Basis | Total | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	86,325	36,797
Measured at Fair Value on a Recurring Basis | Total | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value		2,571
Measured at Fair Value on a Recurring Basis | Level 1 | Total
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	0	2,571
Measured at Fair Value on a Recurring Basis | Level 1 | Total | U.S. government agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	0	0
Measured at Fair Value on a Recurring Basis | Level 1 | Total | State, county and municipals
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	0	0
Measured at Fair Value on a Recurring Basis | Level 1 | Total | Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	0	0
Measured at Fair Value on a Recurring Basis | Level 1 | Total | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	0	0
Measured at Fair Value on a Recurring Basis | Level 1 | Total | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value		2,571
Measured at Fair Value on a Recurring Basis | Level 2 | Total
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	391,654	393,431
Measured at Fair Value on a Recurring Basis | Level 2 | Total | U.S. government agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	21,649	26,209
Measured at Fair Value on a Recurring Basis | Level 2 | Total | State, county and municipals
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	160,460	183,386
Measured at Fair Value on a Recurring Basis | Level 2 | Total | Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	131,644	155,529
Measured at Fair Value on a Recurring Basis | Level 2 | Total | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	77,901	28,307
Measured at Fair Value on a Recurring Basis | Level 2 | Total | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value		0
Measured at Fair Value on a Recurring Basis | Level 3 | Total
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	8,490	9,151
Measured at Fair Value on a Recurring Basis | Level 3 | Total | U.S. government agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	0	0
Measured at Fair Value on a Recurring Basis | Level 3 | Total | State, county and municipals
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	66	658
Measured at Fair Value on a Recurring Basis | Level 3 | Total | Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	0	3
Measured at Fair Value on a Recurring Basis | Level 3 | Total | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value	8,424	8,490
Measured at Fair Value on a Recurring Basis | Level 3 | Total | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value		0
Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale (“AFS”), at fair value		$ 2,571
Equity securities | Measured at Fair Value on a Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities, FV-NI	2,650
Equity securities | Measured at Fair Value on a Recurring Basis | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities, FV-NI	2,650
Equity securities | Measured at Fair Value on a Recurring Basis | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities, FV-NI	0
Equity securities | Measured at Fair Value on a Recurring Basis | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities, FV-NI	$ 0

FAIR VALUE MEASUREMENTS - Chang

FAIR VALUE MEASUREMENTS - Changes in Level 3 assets (Details) - Level 3 - Fair Value, Measurements, Recurring - Securities AFS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Level 3 Fair Value Measurements:
Balance at beginning of year	$ 9,151	$ 9,108
Acquired balances	0	189
Paydowns/Sales/Settlements	(661)	(146)
Balance at end of year	$ 8,490	$ 9,151

FAIR VALUE MEASUREMENTS - Fair

FAIR VALUE MEASUREMENTS - Fair value on a nonrecurring basis (Details) - Measured at Fair Value on a Nonrecurring Basis - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	$ 9,939	$ 17,058
OREO
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	420	1,294
MSR asset
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	6,347	4,097
Level 1 | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	0
Level 1 | OREO
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	0
Level 1 | MSR asset
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	0
Level 2 | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	0
Level 2 | OREO
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	0
Level 2 | MSR asset
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	0
Level 3 | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	9,939	17,058
Level 3 | OREO
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	420	1,294
Level 3 | MSR asset
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	$ 6,347	$ 4,097

FAIR VALUE MEASUREMENTS - Finan

FAIR VALUE MEASUREMENTS - Financial instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financial assets:
Securities available for sale (“AFS”), at fair value	$ 400,144	$ 405,153
Carrying Amount
Financial assets:
Cash and cash equivalents	249,526	154,933
Certificates of deposit in other banks	993	1,746
Securities available for sale (“AFS”), at fair value	400,144	405,153
Other investments	17,997	14,837
Loans held for sale	1,639	4,666
Loans, net	2,153,028	2,075,272
BOLI	66,310	64,453
MSR asset	3,749	3,187
Financial liabilities:
Deposits	2,614,138	2,471,064
Long-term Debt, Fair Value	77,305	78,046
Estimated Fair Value
Financial assets:
Cash and cash equivalents	249,526	154,933
Certificates of deposit in other banks	993	1,746
Securities available for sale (“AFS”), at fair value	400,144	405,153
Other investments	17,997	14,837
Loans held for sale	1,662	4,750
Loans, net	2,139,322	2,068,382
BOLI	66,310	64,453
MSR asset	6,347	4,097
Financial liabilities:
Deposits	2,614,995	2,469,456
Long-term Debt, Fair Value	75,923	77,029
Level 1 | Estimated Fair Value
Financial assets:
Cash and cash equivalents	249,526	154,933
Certificates of deposit in other banks	0	0
Securities available for sale (“AFS”), at fair value	0	2,571
Other investments	2,650	0
Loans held for sale	0	0
Loans, net	0	0
BOLI	66,310	64,453
MSR asset	0	0
Financial liabilities:
Deposits	0	0
Long-term Debt, Fair Value	0	0
Level 2 | Estimated Fair Value
Financial assets:
Cash and cash equivalents	0	0
Certificates of deposit in other banks	993	1,746
Securities available for sale (“AFS”), at fair value	391,654	393,431
Other investments	13,189	13,142
Loans held for sale	1,662	4,750
Loans, net	0	0
BOLI	0	0
MSR asset	0	0
Financial liabilities:
Deposits	0	0
Long-term Debt, Fair Value	34,907	36,510
Level 3 | Estimated Fair Value
Financial assets:
Cash and cash equivalents	0	0
Certificates of deposit in other banks	0	0
Securities available for sale (“AFS”), at fair value	8,490	9,151
Other investments	2,158	1,695
Loans held for sale	0	0
Loans, net	2,139,322	2,068,382
BOLI	0	0
MSR asset	6,347	4,097
Financial liabilities:
Deposits	2,614,995	2,469,456
Long-term Debt, Fair Value	$ 41,016	$ 40,519

PARENT COMPANY ONLY FINANCIAL_3

PARENT COMPANY ONLY FINANCIAL INFORMATION - Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Apr. 29, 2016
Assets
Cash and due from subsidiary	$ 85,896	$ 86,191
Goodwill	107,366	107,366	$ 66,000
Total assets	3,096,535	2,932,433
Liabilities and Stockholders’ Equity
Junior subordinated debentures	30,096	29,616
Other liabilities	17,740	18,444
Stockholders’ equity	386,609	364,178
Total liabilities, noncontrolling interest and stockholders’ equity	3,096,535	2,932,433
Nicolet Bankshares, Inc
Assets
Cash and due from subsidiary	45,279	28,026
Investments	4,500	4,021
Investments in subsidiaries	384,839	379,640
Goodwill	(3,266)	(3,266)
Other assets	53	147
Total assets	431,405	408,568
Liabilities and Stockholders’ Equity
Junior subordinated debentures	30,096	29,616
Subordinated notes	11,957	11,921
Other liabilities	2,743	2,853
Stockholders’ equity	386,609	364,178
Total liabilities, noncontrolling interest and stockholders’ equity	$ 431,405	$ 408,568

PARENT COMPANY ONLY FINANCIAL_4

PARENT COMPANY ONLY FINANCIAL INFORMATION - Statements of Income (Details 1) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Financial Statements, Captions [Line Items]
Interest income	$ 125,537	$ 109,253	$ 75,467
Interest expense	18,889	10,511	7,334
Net interest income	106,648	98,742	68,133
Income tax benefit	(13,446)	(16,267)	(9,371)
Net income	41,353	33,433	18,694
Nicolet Bankshares, Inc
Condensed Financial Statements, Captions [Line Items]
Interest income	52	46	58
Interest expense	2,844	2,415	1,951
Net interest income	(2,792)	(2,369)	(1,893)
Dividend income from subsidiaries	40,775	32,000	35,500
Operating expense	(364)	(369)	(202)
Gain (loss) on investments, net	265	1,411	(500)
Income tax benefit	305	1,329	833
Earnings before equity in undistributed income (loss) of subsidiaries	38,189	32,002	33,738
Equity in undistributed income (loss) of subsidiaries	2,847	1,148	(15,276)
Net income	$ 41,036	$ 33,150	$ 18,462

PARENT COMPANY ONLY FINANCIAL_5

PARENT COMPANY ONLY FINANCIAL INFORMATION - Statements of Cash Flows (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash Flows From Operating Activities:
Net income attributable to Nicolet Bankshares, Inc.	$ 41,353	$ 33,433	$ 18,694
Cash Flows From Financing Activities:
Purchase and retirement of common stock	(22,749)	(15,007)	(5,201)
Proceeds from issuance of common stock, net	1,800	4,030	1,900
Capitalized issuance costs, net	0	(186)	(260)
Redemption of preferred stock		0	(12,200)
Cash dividends paid on preferred stock		0	(633)
Net increase in cash and cash equivalents	94,593	25,830	45,484
Nicolet Bankshares, Inc
Cash Flows From Operating Activities:
Net income attributable to Nicolet Bankshares, Inc.	41,036	33,150	18,462
Adjustments to reconcile net income to net cash provided by operating activities:
Accretion of discounts	515	501	353
(Gain) loss on investments, net	(265)	(1,411)	500
Change in other assets and liabilities, net	(25)	(1,384)	395
Equity in undistributed (income) loss of subsidiaries, net of dividends	(2,847)	(1,148)	15,276
Net cash provided by operating activities	38,414	29,708	34,986
Cash Flows From Investing Activities:
Proceeds from sale of investments	708	317	565
Purchases of investments	(920)	0	0
Net cash paid in business combinations	0	(19,287)	(608)
Net cash provided by (used in) investing activities	(212)	(18,970)	(43)
Cash Flows From Financing Activities:
Purchase and retirement of common stock	(22,749)	(15,007)	(5,201)
Proceeds from issuance of common stock, net	1,800	4,030	1,900
Capitalized issuance costs, net	0	0	(260)
Repayment of long-term borrowings	0	0	(3,916)
Redemption of preferred stock	0	0	(12,200)
Cash dividends paid on preferred stock	0	0	(633)
Net cash provided by (used in) financing activities	(20,949)	(10,977)	(20,310)
Net increase in cash and cash equivalents	17,253	(239)	14,633
Beginning cash and due from subsidiary	28,026	28,265	13,632
Ending cash and due from subsidiary	$ 45,279	$ 28,026	$ 28,265

EARNINGS PER COMMON SHARE (Deta

EARNINGS PER COMMON SHARE (Detail) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from calculation of earnings per common share	100,000	100,000
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from calculation of earnings per common share			0

EARNINGS PER COMMON SHARE (De_2

EARNINGS PER COMMON SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Net income attributable to Nicolet Bankshares, Inc.	$ 41,036	$ 33,150	$ 18,462
Less preferred stock dividends	0	0	633
Net income available to common shareholders	$ 41,036	$ 33,150	$ 17,829
Weighted average common shares outstanding	9,640,258	9,439,951	7,158,367
Effect of dilutive common stock awards	316,000	518,000	356,000
Diluted weighted average common shares outstanding	9,956,353	9,958,160	7,513,971
Basic earnings per common share (in dollars per share)	$ 4.26	$ 3.51	$ 2.49
Diluted earnings per common share (in dollars per share)	$ 4.12	$ 3.33	$ 2.37