Nicolet Bankshares (NIC) 10-Q 2 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Oct. 31, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	NICOLET BANKSHARES INC
Entity Central Index Key	1,174,850
Trading Symbol	ncbs
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		9,525,855
Document Type	10-Q
Document Period End Date	Sep. 30, 2018
Amendment Flag	false
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Small Business	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018		Dec. 31, 2017
Assets
Cash and due from banks	$ 60,346		$ 86,191
Interest-earning deposits	100,066		68,008
Federal funds sold	743		734
Cash and cash equivalents	161,155	[1]	154,933
Certificates of deposit in other banks	995		1,746
Securities available for sale (“AFS”), at fair value	410,911		405,153
Other investments	17,479		14,837
Loans held for sale	2,593		4,666
Loans	2,143,457		2,087,925
Allowance for loan losses	(12,992)		(12,653)
Loans, net	2,130,465		2,075,272
Premises and equipment, net	47,305		47,151
Bank owned life insurance (“BOLI”)	65,820		64,453
Goodwill and other intangibles, net	125,360		128,406
Accrued interest receivable and other assets	38,819		35,816
Total assets	3,000,902		2,932,433
Liabilities:
Noninterest-bearing demand deposits	664,788		631,831
Interest-bearing deposits	1,857,368		1,839,233
Total deposits	2,522,156		2,471,064
Short-term borrowings	0		0
Long-term borrowings	77,241		78,046
Accrued interest payable and other liabilities	23,602		18,444
Total liabilities	2,622,999		2,567,554
Stockholders’ Equity:
Common stock	96		98
Additional paid-in capital	251,631		263,835
Retained earnings	133,501		102,391
Accumulated other comprehensive loss	(8,057)		(2,146)
Total Nicolet Bankshares, Inc. stockholders’ equity	377,171		364,178
Noncontrolling interest	732		701
Total stockholders’ equity and noncontrolling interest	377,903		364,879
Total liabilities, noncontrolling interest and stockholders’ equity	$ 3,000,902		$ 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	9,576,644		9,818,247
Common shares issued	9,604,160		9,849,167
[1]	* Cash and cash equivalents include restricted cash of $7.4 million and $2.4 million at September 30, 2018 and 2017, respectively, for the reserve balance required with the Federal Reserve Bank.

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - $ / shares	Sep. 30, 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 (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Interest income:
Loans, including loan fees	$ 28,997	$ 27,329	$ 84,644	$ 73,098
Investment securities:
Taxable	1,564	1,114	4,503	3,422
Tax-exempt	572	604	1,737	1,761
Other interest income	747	407	2,326	1,136
Total interest income	31,880	29,454	93,210	79,417
Interest expense:
Deposits	4,055	2,364	11,012	5,216
Short-term borrowings	0	0	8	72
Long-term borrowings	883	699	2,571	1,894
Total interest expense	4,938	3,063	13,591	7,182
Net interest income	26,942	26,391	79,619	72,235
Provision for loan losses	340	975	1,360	1,875
Net interest income after provision for loan losses	26,602	25,416	78,259	70,360
Noninterest income:
Mortgage income, net	1,902	1,774	4,510	4,022
BOLI income	1,019	459	1,929	1,314
Rent income	303	285	951	852
Asset gains (losses), net	146	1,305	1,322	2,071
Other income	1,181	899	3,292	2,391
Total noninterest income	10,649	10,164	29,712	26,018
Noninterest expense:
Personnel	12,983	11,488	38,149	32,404
Occupancy, equipment and office	3,660	3,559	10,901	9,613
Business development and marketing	1,334	1,113	4,139	3,359
Data processing	2,375	2,238	7,094	6,428
FDIC expense	245	205	800	582
Intangibles amortization	1,054	1,173	3,336	3,514
Other expense	1,393	1,086	3,718	3,598
Total noninterest expense	23,044	20,862	68,137	59,498
Income before income tax expense	14,207	14,718	39,834	36,880
Income tax expense	3,268	5,133	9,431	12,605
Net income	10,939	9,585	30,403	24,275
Less: Net income attributable to noncontrolling interest	80	74	230	228
Net income attributable to Nicolet Bankshares, Inc.	$ 10,859	$ 9,511	$ 30,173	$ 24,047
Earnings per common share:
Basic (in dollars per share)	$ 1.13	$ 0.97	$ 3.12	$ 2.58
Diluted (in dollars per share)	$ 1.09	$ 0.91	$ 3.02	$ 2.45
Weighted average common shares outstanding:
Basic (in shares)	9,633,158	9,836,646	9,678,726	9,316,814
Diluted (in shares)	9,949,295	10,408,683	10,004,316	9,820,724
Trust services fee income
Noninterest income:
Fees and Commissions	$ 1,638	$ 1,479	$ 4,915	$ 4,431
Brokerage fee income
Noninterest income:
Fees and Commissions	1,732	1,500	5,074	4,192
Service charges on deposit accounts
Noninterest income:
Fees and Commissions	1,247	1,238	3,637	3,367
Card interchange income
Noninterest income:
Fees and Commissions	$ 1,481	$ 1,225	$ 4,082	$ 3,378

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 10,939	$ 9,585	$ 30,403	$ 24,275
Unrealized gains (losses) on securities AFS:
Net unrealized holding gains (losses) arising during the period	(1,836)	834	(6,814)	5,685
Reclassification adjustment for net gains included in income	0	(1,222)	0	(1,220)
Income tax (expense) benefit	497	125	1,840	(1,741)
Total other comprehensive income (loss)	(1,339)	(263)	(4,974)	2,724
Comprehensive income	$ 9,600	$ 9,322	$ 25,429	$ 26,999

Consolidated Statement of Stock

Consolidated Statement of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Noncontrolling Interest
Comprehensive income:
Cumulative Effect of New Accounting Principle in Period of Adoption | Accounting Standards Update 2016-01				$ 937
Balance, December 31, 2017 at Dec. 31, 2017	$ 364,879	$ 98	$ 263,835	102,391	$ (2,146)	$ 701
Comprehensive income:
Net income	30,403			30,173		230
Other comprehensive loss	(4,974)				(4,974)
Stock-based compensation expense	3,613		3,613
Exercise of stock options	1,224	1	1,223
Issuance of common stock	167		167
Purchase and retirement of common stock	(17,210)	(3)	(17,207)
Distribution to noncontrolling interest	(199)					(199)
Adoption of ASU 2016-01 (See Notes 1 and 5) | Accounting Standards Update 2016-01					(937)
Balance, September 30, 2018 at Sep. 30, 2018	$ 377,903	$ 96	$ 251,631	$ 133,501	$ (8,057)	$ 732

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017
Cash Flows From Operating Activities:
Net income		$ 30,403	$ 24,275
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization, and accretion		4,643	7,038
Provision for loan losses		1,360	1,875
Increase in cash surrender value of life insurance		1,367	1,314
Stock-based compensation expense		3,613	1,871
Asset (gains) losses, net		(1,322)	(2,071)
Gain on sale of loans held for sale, net		(4,026)	(3,614)
Proceeds from sale of loans held for sale		184,314	164,726
Origination of loans held for sale		(178,911)	(164,806)
Net change in:
Accrued interest receivable and other assets		(4,952)	239
Accrued interest payable and other liabilities		6,798	1,733
Net cash provided by operating activities		40,553	29,952
Cash Flows From Investing Activities:
Net increase in loans		(50,703)	(126,499)
Net decrease in certificates of deposit in other banks		751	1,490
Purchases of securities AFS		(57,891)	(49,119)
Proceeds from sales of securities AFS		0	10,798
Proceeds from calls and maturities of securities AFS		40,302	34,426
Purchases of other investments		(634)	(3,256)
Proceeds from sales of other investments		807	6,519
Proceeds from redemption of BOLI		561	0
Net increase in premises and equipment		(2,974)	(2,958)
Net decrease in other real estate and other assets		1,486	2,470
Net cash received in business combination		0	9,119
Net cash used by investing activities		(68,295)	(117,010)
Cash Flows From Financing Activities:
Net increase in deposits		51,171	22,054
Net increase in short-term borrowings		0	12,900
Proceeds from long-term borrowings		0	30,000
Repayments of long-term borrowings		(1,189)	(4,487)
Purchase and retirement of common stock		(17,210)	(7,462)
Capitalized issuance costs, net		0	(186)
Proceeds from issuance of common stock		167	175
Proceeds from exercise of stock options		1,224	1,064
Distribution to noncontrolling interest		(199)	0
Net cash provided by financing activities		33,964	54,058
Net increase (decrease) in cash and cash equivalents		6,222	(33,000)
Cash and cash equivalents:
Beginning		154,933	129,103
Ending	[1]	161,155	96,103
Supplemental Disclosures of Cash Flow Information:
Cash paid for interest		13,294	7,117
Cash paid for taxes		9,325	8,805
Transfer of loans and bank premises to other real estate owned		587	828
Capitalized mortgage servicing rights		696	679
Transfer of loans from held for sale to held for investment		0	3,236
Acquisitions:
Fair value of assets acquired		0	439,000
Fair value of liabilities assumed		0	398,000
Net assets acquired		$ 0	$ 41,000
[1]	* Cash and cash equivalents include restricted cash of $7.4 million and $2.4 million at September 30, 2018 and 2017, respectively, for the reserve balance required with the Federal Reserve Bank.

Consolidated Statements of Ca_2

Consolidated Statements of Cash Flows (Unaudited) (Parentheticals) - USD ($) $ in Millions	Sep. 30, 2018	Sep. 30, 2017
Statement of Cash Flows [Abstract]
Restricted cash and cash equivalents	$ 7.4	$ 2.4

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation General In the opinion of management, the accompanying unaudited consolidated financial statements contain all adjustments necessary to present fairly the consolidated balance sheets, statements of income, comprehensive income, changes in stockholders’ equity and cash flows of Nicolet Bankshares, Inc. (the “Company” or “Nicolet”) and its subsidiaries, for the periods presented, and all such adjustments are of a normal recurring nature. All material intercompany transactions and balances have been eliminated. The results of operations for the interim periods are not necessarily indicative of the results to be expected for the entire year. These interim consolidated financial statements have been prepared according to the rules and regulations of the Securities and Exchange Commission and, therefore, certain information and footnote disclosures normally presented in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”) have been omitted or abbreviated. These consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and footnotes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 . Critical Accounting Policies and 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, the 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. There have been no material changes or developments with respect to the assumptions or methodologies that the Company uses when applying what management believes are critical accounting policies and developing critical accounting estimates as disclosed in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 . Recent Accounting Developments 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, including 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 5 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 10 for the new disclosures related to Topic 606. Operating Segment 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. Reclassifications Certain amounts in the 2017 consolidated financial statements have been reclassified to conform to the 2018 presentation.

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2018
Business Combinations [Abstract]
Acquisitions	Acquisitions 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. 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 Nicolet National Bank (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.

Earnings per Common Share

Earnings per Common Share	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
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 shares adjusted for the dilutive effect of common stock awards (outstanding stock options and unvested restricted stock), if any. Presented below are the calculations for basic and diluted earnings per common share. Three Months Ended September 30, Nine Months Ended September 30, (In thousands, except per share data) 2018 2017 2018 2017 Net income attributable to Nicolet Bankshares, Inc. $ 10,859 $ 9,511 $ 30,173 $ 24,047 Weighted average common shares outstanding 9,633 9,837 9,679 9,317 Effect of dilutive common stock awards 316 572 325 504 Diluted weighted average common shares outstanding 9,949 10,409 10,004 9,821 Basic earnings per common share* $ 1.13 $ 0.97 $ 3.12 $ 2.58 Diluted earnings per common share* $ 1.09 $ 0.91 $ 3.02 $ 2.45 *Cumulative quarterly per share performance may not equal annual per share totals due to the effects of the amount and timing of capital increases. When computing earnings per share for an interim period, the denominator is based on the weighted average shares outstanding during the interim period, and not on an annualized weighted average basis. Accordingly, the sum of the earnings per share data for the quarters will not necessarily equal the year to date earnings per share data. For the three and nine months ended September 30, 2018 , options to purchase approximately 0.1 million shares are excluded from the calculation of diluted earnings per common share as the effect of their exercise would have been anti-dilutive. There was no anti-dilutive effect of options outstanding for the three and nine months ended September 30, 2017 .

Stock-based Compensation

Stock-based Compensation	9 Months Ended
	Sep. 30, 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. At September 30, 2018 , approximately 144,000 shares were available for grant under these stock-based compensation plans. A Black-Scholes model is utilized to estimate the fair value of stock option grants, while the market price of the Company’s stock at the date of grant is used to estimate the fair value of restricted stock awards. The weighted average assumptions used in the Black-Scholes model for valuing stock option grants were as follows. Nine Months Ended September 30, 2018 2017 Dividend yield — % — % Expected volatility 25 % 25 % Risk-free interest rate 2.48 % 2.13 % Expected average life 7 years 7 years Weighted average per share fair value of options $ 17.60 $ 15.44 Activity in the Company’s Stock Incentive Plans is summarized in the following tables. Stock Options Option Shares Outstanding Weighted Average Exercise Price Weighted Average Remaining Life (Years) Aggregate Intrinsic Value (in thousands) Outstanding - December 31, 2017 1,643,255 $ 39.82 Granted 10,000 54.06 Exercise of stock options * (56,881 ) 21.53 Forfeited (6,500 ) 39.43 Outstanding - September 30, 2018 1,589,874 $ 40.57 7.6 $ 22,429 Exercisable - September 30, 2018 543,886 $ 32.00 6.4 $ 12,243 * 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; accordingly, 2,194 such shares were surrendered to the Company during the nine months ended September 30, 2018 . 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 for both the nine months ended September 30, 2018 and 2017 was approximately $1.8 million . Restricted Stock Weighted Average Grant Date Fair Value Restricted Shares Outstanding Outstanding - December 31, 2017 $ 34.26 30,920 Granted 55.64 7,510 Vested * 37.44 (10,911 ) Forfeited 16.50 (3 ) Outstanding - September 30, 2018 $ 38.84 27,516 * The terms of the restricted stock agreements permit the surrender of shares to the Company upon vesting in order to satisfy applicable tax withholding requirements at the minimum statutory withholding rate, and accordingly, 1,615 shares were surrendered during the nine months ended September 30, 2018 . The Company recognized approximately $3.4 million and $1.9 million of stock-based compensation expense (included in personnel on the consolidated statements of income) during the nine months ended September 30, 2018 and 2017 , respectively, associated with its common stock awards granted to officers and employees. In addition, during the third quarter of 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 September 30, 2018 , there was approximately $13.7 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 for both the nine months ended September 30, 2018 and 2017 , respectively, for the tax impact of stock option exercises and vesting of restricted stock.

Securities Available for Sale

Securities Available for Sale	9 Months Ended
	Sep. 30, 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. September 30, 2018 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. government agency securities $ 27,133 $ — $ 879 $ 26,254 State, county and municipals 169,431 38 4,647 164,822 Mortgage-backed securities 140,427 85 4,667 135,845 Corporate debt securities 84,957 165 1,132 83,990 Total $ 421,948 $ 288 $ 11,325 $ 410,911 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 Total $ 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. Such securities are no longer reflected as securities AFS. 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 statement of 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 $475,000 for the nine months ended September 30, 2018 , in the consolidated statements of income for the change in fair value on equity securities since adoption. In addition, the approximately $2.8 million current fair value of equity securities is now reflected within other investments on the consolidated balance sheets rather than as securities AFS. Prior periods have not been restated for the impact of this accounting change. See Note 1 for additional information on this new accounting standard. The following table represents gross unrealized losses and the related estimated fair value of investment securities available for sale, aggregated by investment category and length of time individual securities have been in a continuous unrealized loss position. September 30, 2018 Less than 12 months 12 months or more Total ($ in thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Number of Securities U.S. government agency securities $ — $ — $ 26,254 $ 879 $ 26,254 $ 879 2 State, county and municipals 71,359 1,168 81,418 3,479 152,777 4,647 453 Mortgage-backed securities 32,929 727 93,312 3,940 126,241 4,667 212 Corporate debt securities 69,816 1,132 — — 69,816 1,132 37 Total $ 174,104 $ 3,027 $ 200,984 $ 8,298 $ 375,088 $ 11,325 704 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 Total $ 218,748 $ 2,248 $ 114,863 $ 2,765 $ 333,611 $ 5,013 687 As of September 30, 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 impairments charged to earnings during the nine months ended September 30, 2018 or 2017 . 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. September 30, 2018 (in thousands) Amortized Cost Fair Value Due in less than one year $ 21,592 $ 21,559 Due in one year through five years 157,636 154,294 Due after five years through ten years 95,324 92,078 Due after ten years 6,969 7,135 281,521 275,066 Mortgage-backed securities 140,427 135,845 Securities available for sale $ 421,948 $ 410,911 Proceeds from the sale of securities AFS were as follows. Nine Months Ended September 30, (in thousands) 2018 2017 Gross gains $ — $ 1,227 Gross losses — (7 ) Gains (losses) on sales of securities AFS, net $ — $ 1,220 Proceeds from sales of securities AFS $ — $ 10,798

Loans, Allowance for Loan Losse

Loans, Allowance for Loan Losses, and Credit Quality	9 Months Ended
	Sep. 30, 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. September 30, 2018 December 31, 2017 (in thousands) Amount % of Total Amount % of Total Commercial & industrial $ 665,754 31.1 % $ 637,337 30.5 % Owner-occupied commercial real estate (“CRE”) 449,151 21.0 430,043 20.6 Agricultural (“AG”) production 35,727 1.7 35,455 1.7 AG real estate 52,378 2.4 51,778 2.5 CRE investment 331,312 15.5 314,463 15.1 Construction & land development 86,533 4.0 89,660 4.3 Residential construction 30,295 1.4 36,995 1.8 Residential first mortgage 357,163 16.6 363,352 17.4 Residential junior mortgage 109,692 5.1 106,027 5.1 Retail & other 25,452 1.2 22,815 1.0 Loans 2,143,457 100.0 % 2,087,925 100.0 % Less allowance for loan losses (“ALLL”) 12,992 12,653 Loans, net $ 2,130,465 $ 2,075,272 Allowance for loan losses to loans 0.61 % 0.61 % As a further breakdown, loans are summarized by originated and acquired as follows. September 30, 2018 December 31, 2017 (in thousands) Originated Amount % of Total Acquired Amount % of Total Originated Amount % of Total Acquired Amount % of Total Commercial & industrial $ 551,395 38.9 % $ 114,359 15.8 % $ 488,600 39.3 % $ 148,737 17.6 % Owner-occupied CRE 274,036 19.3 175,115 24.2 237,548 19.1 192,495 22.8 AG production 10,821 0.8 24,906 3.4 11,102 0.9 24,353 2.9 AG real estate 29,685 2.1 22,693 3.1 27,831 2.2 23,947 2.8 CRE investment 151,335 10.7 179,977 24.8 113,862 9.2 200,601 23.8 Construction & land development 63,106 4.4 23,427 3.2 56,061 4.5 33,599 4.0 Residential construction 30,245 2.1 50 0.1 33,615 2.7 3,380 0.4 Residential first mortgage 211,474 14.9 145,689 20.1 191,186 15.4 172,166 20.4 Residential junior mortgage 74,366 5.2 35,326 4.9 65,643 5.3 40,384 4.8 Retail & other 22,464 1.6 2,988 0.4 18,254 1.4 4,561 0.5 Loans 1,418,927 100.0 % 724,530 100.0 % 1,243,702 100.0 % 844,223 100.0 % Less ALLL 11,118 1,874 10,542 2,111 Loans, net $ 1,407,809 $ 722,656 $ 1,233,160 $ 842,112 ALLL to loans 0.78 % 0.26 % 0.85 % 0.25 % A roll forward of the allowance for loan losses is summarized as follows. Nine Months Ended Year Ended (in thousands) September 30, 2018 September 30, 2017 December 31, 2017 Beginning balance $ 12,653 $ 11,820 $ 11,820 Provision for loan losses 1,360 1,875 2,325 Charge-offs (1,110 ) (1,156 ) (1,604 ) Recoveries 89 71 112 Net charge-offs (1,021 ) (1,085 ) (1,492 ) Ending balance $ 12,992 $ 12,610 $ 12,653 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. The following tables present the balance and activity in the ALLL by portfolio segment and the recorded investment in loans by portfolio segment. TOTAL – Nine Months Ended September 30, 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 1,043 293 (8 ) (2 ) (8 ) (230 ) (41 ) 119 (55 ) 249 1,360 Charge-offs (743 ) (64 ) — — (37 ) — — (85 ) — (181 ) (1,110 ) Recoveries 30 12 — — — — — 3 31 13 89 Net charge-offs (713 ) (52 ) — — (37 ) — — (82 ) 31 (168 ) (1,021 ) Ending balance $ 5,264 $ 2,848 $ 121 $ 294 $ 1,343 $ 496 $ 210 $ 1,646 $ 464 $ 306 $ 12,992 As percent of ALLL 40.5 % 21.9 % 0.9 % 2.3 % 10.3 % 3.8 % 1.6 % 12.7 % 3.6 % 2.4 % 100.0 % ALLL: Individually evaluated $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — Collectively evaluated 5,264 2,848 121 294 1,343 496 210 1,646 464 306 12,992 Ending balance $ 5,264 $ 2,848 $ 121 $ 294 $ 1,343 $ 496 $ 210 $ 1,646 $ 464 $ 306 $ 12,992 Loans: Individually evaluated $ 5,858 $ 1,548 $ — $ 234 $ 2,876 $ 603 $ — $ 2,663 $ 57 $ 12 $ 13,851 Collectively evaluated 659,896 447,603 35,727 52,144 328,436 85,930 30,295 354,500 109,635 25,440 2,129,606 Total loans $ 665,754 $ 449,151 $ 35,727 $ 52,378 $ 331,312 $ 86,533 $ 30,295 $ 357,163 $ 109,692 $ 25,452 $ 2,143,457 Less ALLL 5,264 2,848 121 294 1,343 496 210 1,646 464 306 12,992 Net loans $ 660,490 $ 446,303 $ 35,606 $ 52,084 $ 329,969 $ 86,037 $ 30,085 $ 355,517 $ 109,228 $ 25,146 $ 2,130,465 As a further breakdown, the ALLL is summarized by originated and acquired as follows. Originated – Nine Months Ended September 30, 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 1,143 349 (4 ) 9 (13 ) (217 ) (25 ) 165 (43 ) 247 1,611 Charge-offs (743 ) (64 ) — — (37 ) — — (85 ) — (178 ) (1,107 ) Recoveries 29 1 — — — — — — 29 13 72 Net charge-offs (714 ) (63 ) — — (37 ) — — (85 ) 29 (165 ) (1,035 ) Ending balance $ 4,621 $ 2,401 $ 108 $ 244 $ 1,104 $ 411 $ 175 $ 1,377 $ 395 $ 282 $ 11,118 As percent of ALLL 41.6 % 21.6 % 1.0 % 2.2 % 9.9 % 3.7 % 1.6 % 12.4 % 3.5 % 2.5 % 100.0 % Loans: Individually evaluated $ 2,553 $ 328 $ — $ — $ 918 $ — $ — $ 251 $ — $ — $ 4,050 Collectively evaluated 548,842 273,708 10,821 29,685 150,417 63,106 30,245 211,223 74,366 22,464 1,414,877 Total loans $ 551,395 $ 274,036 $ 10,821 $ 29,685 $ 151,335 $ 63,106 $ 30,245 $ 211,474 $ 74,366 $ 22,464 $ 1,418,927 Less ALLL 4,621 2,401 108 244 1,104 411 175 1,377 395 282 11,118 Net loans $ 546,774 $ 271,635 $ 10,713 $ 29,441 $ 150,231 $ 62,695 $ 30,070 $ 210,097 $ 73,971 $ 22,182 $ 1,407,809 Acquired – Nine Months Ended September 30, 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 (100 ) (56 ) (4 ) (11 ) 5 (13 ) (16 ) (46 ) (12 ) 2 (251 ) Charge-offs — — — — — — — — — (3 ) (3 ) Recoveries 1 11 — — — — — 3 2 — 17 Net charge-offs 1 11 — — — — — 3 2 (3 ) 14 Ending balance $ 643 $ 447 $ 13 $ 50 $ 239 $ 85 $ 35 $ 269 $ 69 $ 24 $ 1,874 As percent of ALLL 34.3 % 23.9 % 0.7 % 2.7 % 12.7 % 4.5 % 1.9 % 14.3 % 3.7 % 1.3 % 100.0 % Loans: Individually evaluated $ 3,305 $ 1,220 $ — $ 234 $ 1,958 $ 603 $ — $ 2,412 $ 57 $ 12 $ 9,801 Collectively evaluated 111,054 173,895 24,906 22,459 178,019 22,824 50 143,277 35,269 2,976 714,729 Total loans $ 114,359 $ 175,115 $ 24,906 $ 22,693 $ 179,977 $ 23,427 $ 50 $ 145,689 $ 35,326 $ 2,988 $ 724,530 Less ALLL 643 447 13 50 239 85 35 269 69 24 1,874 Net loans $ 113,716 $ 174,668 $ 24,893 $ 22,643 $ 179,738 $ 23,342 $ 15 $ 145,420 $ 35,257 $ 2,964 $ 722,656 The following tables present the balance and activity in the ALLL by portfolio segment and the recorded investment in loans by portfolio segment. 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 percent 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 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 percent 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 percent 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 table presents nonaccrual loans by portfolio segment in total and then as a further breakdown by originated or acquired. Total Nonaccrual Loans (in thousands) September 30, 2018 % of Total December 31, 2017 % of Total Commercial & industrial $ 5,803 57.0 % $ 6,016 46.0 % Owner-occupied CRE 474 4.6 533 4.1 AG production — — — — AG real estate 175 1.7 186 1.4 CRE investment 1,381 13.6 4,531 34.6 Construction & land development 80 0.8 — — Residential construction 28 0.3 80 0.6 Residential first mortgage 1,973 19.4 1,587 12.1 Residential junior mortgage 268 2.6 158 1.2 Retail & other — — 4 — Nonaccrual loans $ 10,182 100.0 % $ 13,095 100.0 % Percent of total loans 0.5 % 0.6 % September 30, 2018 December 31, 2017 (in thousands) Originated Amount % of Total Acquired Amount % of Total Originated Amount % of Total Acquired Amount % of Total Commercial & industrial $ 2,729 55.9 % $ 3,074 58.0 % $ 2,296 70.0 % $ 3,720 37.9 % Owner-occupied CRE 360 7.4 114 2.2 86 2.6 447 4.6 AG production — — — — — — — — AG real estate — — 175 3.3 — — 186 1.9 CRE investment 918 18.8 463 8.7 549 16.8 3,982 40.6 Construction & land development — — 80 1.5 — — — — Residential construction 28 0.6 — — — — 80 0.8 Residential first mortgage 777 15.9 1,196 22.5 331 10.1 1,256 12.8 Residential junior mortgage 66 1.4 202 3.8 12 0.4 146 1.4 Retail & other — — — — 4 0.1 — — Nonaccrual loans $ 4,878 100.0 % $ 5,304 100.0 % $ 3,278 100.0 % $ 9,817 100.0 % Percent of nonaccrual loans 47.9 % 52.1 % 25.0 % 75.0 % The following tables present past due loans by portfolio segment. September 30, 2018 (in thousands) 30-89 Days Past Due (accruing) 90 Days & Over or nonaccrual Current Total Commercial & industrial $ 30 $ 5,803 $ 659,921 $ 665,754 Owner-occupied CRE — 474 448,677 449,151 AG production — — 35,727 35,727 AG real estate 48 175 52,155 52,378 CRE investment — 1,381 329,931 331,312 Construction & land development 104 80 86,349 86,533 Residential construction 212 28 30,055 30,295 Residential first mortgage 638 1,973 354,552 357,163 Residential junior mortgage 31 268 109,393 109,692 Retail & other 61 — 25,391 25,452 Total loans $ 1,124 $ 10,182 $ 2,132,151 $ 2,143,457 Percent of total loans 0.1 % 0.4 % 99.5 % 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. September 30, 2018 (in thousands) Grades 1- 4 Grade 5 Grade 6 Grade 7 Grade 8 Grade 9 Total Commercial & industrial $ 630,681 $ 20,123 $ 2,725 $ 12,225 $ — $ — $ 665,754 Owner-occupied CRE 412,146 28,643 2,234 6,128 — — 449,151 AG production 30,195 2,892 2,342 298 — — 35,727 AG real estate 45,288 3,483 3,026 581 — — 52,378 CRE investment 321,138 7,086 1,006 2,082 — — 331,312 Construction & land development 81,296 5,141 16 80 — — 86,533 Residential construction 30,267 — — 28 — — 30,295 Residential first mortgage 352,778 1,388 520 2,477 — — 357,163 Residential junior mortgage 109,394 17 — 281 — — 109,692 Retail & other 25,452 — — — — — 25,452 Total loans $ 2,038,635 $ 68,773 $ 11,869 $ 24,180 $ — $ — $ 2,143,457 Percent of total 95.1 % 3.2 % 0.6 % 1.1 % — — 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 94.8 % 2.8 % 1.1 % 1.3 % — — 100.0 % The following tables present impaired loans. Total Impaired Loans – September 30, 2018 (in thousands) Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized Commercial & industrial $ 5,858 $ 9,737 $ — $ 6,389 $ 534 Owner-occupied CRE 1,548 2,010 — 1,614 113 AG production — 6 — — 1 AG real estate 234 293 — 238 14 CRE investment 2,876 3,792 — 2,988 294 Construction & land development 603 1,506 — 603 16 Residential construction — — — — — Residential first mortgage 2,663 3,122 — 2,734 159 Residential junior mortgage 57 360 — 62 19 Retail & other 12 13 — 12 1 Total $ 13,851 $ 20,839 $ — $ 14,640 $ 1,151 Originated impaired loans $ 4,050 $ 4,050 $ — $ 4,453 $ 213 Acquired impaired loans 9,801 16,789 — 10,187 938 Total $ 13,851 $ 20,839 $ — $ 14,640 $ 1,151 Total Impaired Loans – 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 non-accretable mark and a zero accretable mark. At September 30, 2018 , $9.8 million of the $43.6 million remain in impaired loans. Non-accretable discount on purchased credit impaired (“PCI”) loans : Nine Months Ended Year Ended (in thousands) September 30, 2018 September 30, 2017 December 31, 2017 Balance at beginning of period $ 9,471 $ 14,327 $ 14,327 Acquired balance, net — 8,352 8,352 Accretion to loan interest income (1,872 ) (5,925 ) (7,995 ) Transferred to accretable (513 ) — (1,936 ) Disposals of loans (97 ) (1,121 ) (3,277 ) Balance at end of period $ 6,989 $ 15,633 $ 9,471 Troubled Debt Restructurings At September 30, 2018 , there were five loans classified as troubled debt restructurings with a current outstanding balance of $0.7 million and 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 pre-modification balance of $6.9 million . There were no loans classified as troubled debt restructurings during the previous twelve months that subsequently defaulted during the nine months ended September 30, 2018 . As of September 30, 2018 , there were no commitments to lend additional funds to debtors whose terms have been modified in troubled debt restructurings.

Goodwill and Other Intangibles

Goodwill and Other Intangibles and Mortgage Servicing Rights	9 Months Ended
	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangibles and Mortgage Servicing Rights	Goodwill and Other Intangibles and Mortgage Servicing Rights 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 quarterly assessment indicated no impairment charge on goodwill, core deposit intangibles or customer list intangibles was required for the year ended December 31, 2017 or the nine months ended September 30, 2018 . Nine Months Ended Year Ended (in thousands) September 30, 2018 December 31, 2017 Goodwill $ 107,366 $ 107,366 Core deposit intangibles 13,488 16,477 Customer list intangibles 4,506 4,563 Other intangibles 17,994 21,040 Goodwill and other intangibles, net $ 125,360 $ 128,406 Goodwill : Goodwill was $107.4 million at both September 30, 2018 and December 31, 2017 . During 2017, goodwill increased due to the First Menasha acquisition. See Note 2 for additional information on the First Menasha acquisition. Other intangible assets : 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 2 for additional information on Nicolet's acquisitions. Nine Months Ended Year Ended (in thousands) September 30, 2018 December 31, 2017 Core deposit intangibles: Gross carrying amount $ 29,015 $ 29,015 Accumulated amortization (15,527 ) (12,538 ) Net book value $ 13,488 $ 16,477 Additions during the period $ — $ 3,670 Amortization during the period $ 2,989 $ 4,294 Customer list intangibles: Gross carrying amount $ 5,523 $ 5,233 Accumulated amortization (1,017 ) (670 ) Net book value $ 4,506 $ 4,563 Additions during the period $ 290 $ 870 Amortization during the period $ 347 $ 401 Mortgage servicing rights : Mortgage servicing rights are amortized in proportion to and over the period of estimated net servicing income, and assessed for impairment at each reporting date, with the amortization recorded in mortgage income, net, in the consolidated statements of income. Mortgage servicing rights are carried at the lower of the initial capitalized amount, net of accumulated amortization, or estimated fair value, and are included in other assets in the consolidated balance sheets. Activity in the mortgage servicing rights asset was as follows. Nine Months Ended Year Ended (in thousands) September 30, 2018 December 31, 2017 Mortgage servicing rights (MSR) asset: MSR asset at beginning of year $ 3,187 $ 1,922 Capitalized MSR 696 876 MSR asset acquired — 874 Amortization during the period (464 ) (485 ) MSR asset at end of period $ 3,419 $ 3,187 Fair value of MSR asset at end of period $ 4,304 $ 4,097 Residential mortgage loans serviced for others $ 560,607 $ 518,419 Net book value of MSR asset to loans serviced for others 0.61 % 0.61 % The Company periodically evaluates its mortgage servicing rights asset for impairment. At each reporting date, impairment is assessed based on an estimated fair value using estimated prepayment speeds of the underlying mortgage loans serviced and stratifications based on the risk characteristics of the underlying loans serviced (predominantly loan type and note interest rate). No valuation allowance or impairment charge was recorded for the year ended December 31, 2017 or the nine months ended September 30, 2018 . See Note 9 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 the September 30, 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 Year ending December 31, 2018 (remaining three months) $ 926 $ 127 $ 161 2019 3,337 507 643 2020 2,657 507 814 2021 2,167 507 381 2022 1,735 507 381 Thereafter 2,666 2,351 1,039 Total $ 13,488 $ 4,506 $ 3,419

Short and Long-Term Borrowings

Short and Long-Term Borrowings	9 Months Ended
	Sep. 30, 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 maturity of one year or less) outstanding at September 30, 2018 or December 31, 2017 . Long-Term Borrowings: The components of long-term borrowings (borrowing with an original maturity greater than one year) were as follows. (in thousands) September 30, 2018 December 31, 2017 FHLB advances $ 35,317 $ 36,509 Junior subordinated debentures 29,976 29,616 Subordinated notes 11,948 11,921 Total long-term borrowings $ 77,241 $ 78,046 FHLB Advances : The FHLB advances bear fixed rates, require interest-only monthly payments, and have maturity dates through 2022. The weighted average rate of the FHLB advances was 1.72% and 1.71% at September 30, 2018 and December 31, 2017 , respectively. 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 at par plus any accrued but unpaid interest. At September 30, 2018 and December 31, 2017 , $28.8 million and $28.5 million , respectively, qualify as Tier 1 capital. Junior Subordinated Debentures (in thousands) Maturity Date Par 9/30/2018 Unamortized Discount 9/30/2018 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 (3,421 ) 6,889 6,739 2006 Baylake Corp. (3) 9/30/2036 16,598 (4,179 ) 12,419 12,242 2004 First Menasha Bancshares, Inc. (4) 3/17/2034 5,155 (673 ) 4,482 4,449 Total $ 38,249 $ (8,273 ) $ 29,976 $ 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 3.76% and 3.02% as of September 30, 2018 and December 31, 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 3.75% and 3.04% as of September 30, 2018 and December 31, 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 rates were 5.12% and 4.39% as of September 30, 2018 and December 31, 2017 , respectively. Subordinated 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. The carrying value of these subordinated Notes was $11.9 million at both September 30, 2018 and December 31, 2017 .

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 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 September 30, 2018 U.S. government agency securities $ 26,254 $ — $ 26,254 $ — State, county and municipals 164,822 — 164,756 66 Mortgage-backed securities 135,845 — 135,845 — Corporate debt securities 83,990 — 75,552 8,438 Securities AFS $ 410,911 $ — $ 402,407 $ 8,504 Other investments (equity securities) * $ 2,778 $ 2,778 $ — $ — 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 $2.8 million current fair value of equity securities is now reflected within other investments on the consolidated balance sheets instead of in securities AFS at December 31, 2017. 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 5 for 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, as 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 September 30, 2018 and December 31, 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 the Level 3 securities AFS measured at fair value on a recurring basis. (in thousands) Nine Months Ended Year Ended Level 3 Fair Value Measurements: September 30, 2018 December 31, 2017 Balance at beginning of year $ 9,151 $ 9,108 Acquired balance — 189 Paydowns/Sales/Settlements (647 ) (146 ) Balance at end of period $ 8,504 $ 9,151 Nonrecurring basis fair value measurements: The following table presents the Company’s assets measured at fair value on a nonrecurring basis for the periods presented, aggregated by 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 September 30, 2018 Impaired loans $ 13,851 $ — $ — $ 13,851 Other real estate owned (“OREO”) 1,281 — — 1,281 MSR asset 4,304 — — 4,304 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. September 30, 2018 (in thousands) Carrying Amount Estimated Fair Value Level 1 Level 2 Level 3 Financial assets: Cash and cash equivalents $ 161,155 $ 161,155 $ 161,155 $ — $ — Certificates of deposit in other banks 995 995 — 995 — Securities AFS 410,911 410,911 — 402,407 8,504 Other investments, including equity securities 17,479 17,479 2,778 13,117 1,584 Loans held for sale 2,593 2,643 — 2,643 — Loans, net 2,130,465 2,103,456 — — 2,103,456 BOLI 65,820 65,820 65,820 — — MSR asset 3,419 4,304 — — 4,304 Financial liabilities: Deposits $ 2,522,156 $ 2,523,832 $ — $ — $ 2,523,832 Long-term borrowings 77,241 76,198 — 35,300 40,898 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, bank owned life insurance, short-term borrowings, and nonmaturing deposits, 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 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 non-interest 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 evaluation represents a Level 3 measurement. Lending-related commitments : At September 30, 2018 and December 31, 2017 , the estimated fair value of letters of credit and outstanding mandatory commitments to sell residential mortgage loans into the secondary market was insignificant. 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.

Revenue Recognition

Revenue Recognition	9 Months Ended
	Sep. 30, 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.

Basis of Presentation (Policies

Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
General	General In the opinion of management, the accompanying unaudited consolidated financial statements contain all adjustments necessary to present fairly the consolidated balance sheets, statements of income, comprehensive income, changes in stockholders’ equity and cash flows of Nicolet Bankshares, Inc. (the “Company” or “Nicolet”) and its subsidiaries, for the periods presented, and all such adjustments are of a normal recurring nature. All material intercompany transactions and balances have been eliminated. The results of operations for the interim periods are not necessarily indicative of the results to be expected for the entire year. These interim consolidated financial statements have been prepared according to the rules and regulations of the Securities and Exchange Commission and, therefore, certain information and footnote disclosures normally presented in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”) have been omitted or abbreviated. These consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and footnotes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 .
Critical Accounting Policies and Estimates	Critical Accounting Policies and 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, the 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. There have been no material changes or developments with respect to the assumptions or methodologies that the Company uses when applying what management believes are critical accounting policies and developing critical accounting estimates as disclosed in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 .
Recent Accounting Developments Adopted	Recent Accounting Developments 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, including 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 5 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 10 for the new disclosures related to Topic 606.
Operating Segment	Operating Segment 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.
Reclassifications	Reclassifications Certain amounts in the 2017 consolidated financial statements have been reclassified to conform to the 2018 presentation.

Earnings per Common Share (Tabl

Earnings per Common Share (Tables)	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Schedule of basic and diluted earnings (loss) per common share	Presented below are the calculations for basic and diluted earnings per common share. Three Months Ended September 30, Nine Months Ended September 30, (In thousands, except per share data) 2018 2017 2018 2017 Net income attributable to Nicolet Bankshares, Inc. $ 10,859 $ 9,511 $ 30,173 $ 24,047 Weighted average common shares outstanding 9,633 9,837 9,679 9,317 Effect of dilutive common stock awards 316 572 325 504 Diluted weighted average common shares outstanding 9,949 10,409 10,004 9,821 Basic earnings per common share* $ 1.13 $ 0.97 $ 3.12 $ 2.58 Diluted earnings per common share* $ 1.09 $ 0.91 $ 3.02 $ 2.45 *Cumulative quarterly per share performance may not equal annual per share totals due to the effects of the amount and timing of capital increases. When computing earnings per share for an interim period, the denominator is based on the weighted average shares outstanding during the interim period, and not on an annualized weighted average basis. Accordingly, the sum of the earnings per share data for the quarters will not necessarily equal the year to date earnings per share data.

Stock-based Compensation (Table

Stock-based Compensation (Tables)	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of weighted average assumption for stock option	The weighted average assumptions used in the Black-Scholes model for valuing stock option grants were as follows. Nine Months Ended September 30, 2018 2017 Dividend yield — % — % Expected volatility 25 % 25 % Risk-free interest rate 2.48 % 2.13 % Expected average life 7 years 7 years Weighted average per share fair value of options $ 17.60 $ 15.44
Schedule of stock options outstanding	Activity in the Company’s Stock Incentive Plans is summarized in the following tables. Stock Options Option Shares Outstanding Weighted Average Exercise Price Weighted Average Remaining Life (Years) Aggregate Intrinsic Value (in thousands) Outstanding - December 31, 2017 1,643,255 $ 39.82 Granted 10,000 54.06 Exercise of stock options * (56,881 ) 21.53 Forfeited (6,500 ) 39.43 Outstanding - September 30, 2018 1,589,874 $ 40.57 7.6 $ 22,429 Exercisable - September 30, 2018 543,886 $ 32.00 6.4 $ 12,243 * 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; accordingly, 2,194 such shares were surrendered to the Company during the nine months ended September 30, 2018 .
Schedule of restricted stock awards	Restricted Stock Weighted Average Grant Date Fair Value Restricted Shares Outstanding Outstanding - December 31, 2017 $ 34.26 30,920 Granted 55.64 7,510 Vested * 37.44 (10,911 ) Forfeited 16.50 (3 ) Outstanding - September 30, 2018 $ 38.84 27,516 * The terms of the restricted stock agreements permit the surrender of shares to the Company upon vesting in order to satisfy applicable tax withholding requirements at the minimum statutory withholding rate, and accordingly, 1,615 shares were surrendered during the nine months ended September 30, 2018 .

Securities Available for Sale (

Securities Available for Sale (Tables)	9 Months Ended
	Sep. 30, 2018
Debt Securities, Available-for-sale [Abstract]
Schedule of amortized cost and fair value of securities available for sale	Amortized cost and fair value of securities available for sale are summarized as follows. September 30, 2018 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. government agency securities $ 27,133 $ — $ 879 $ 26,254 State, county and municipals 169,431 38 4,647 164,822 Mortgage-backed securities 140,427 85 4,667 135,845 Corporate debt securities 84,957 165 1,132 83,990 Total $ 421,948 $ 288 $ 11,325 $ 410,911 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 Total $ 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. Such securities are no longer reflected as securities AFS. 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 statement of 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 $475,000 for the nine months ended September 30, 2018 , in the consolidated statements of income for the change in fair value on equity securities since adoption. In addition, the approximately $2.8 million current fair value of equity securities is now reflected within other investments on the consolidated balance sheets rather than as securities AFS. Prior periods have not been restated for the impact of this accounting change. See Note 1 for additional information on this new accounting standard.
Schedule of unrealized losses and fair value	The following table represents gross unrealized losses and the related estimated fair value of investment securities available for sale, aggregated by investment category and length of time individual securities have been in a continuous unrealized loss position. September 30, 2018 Less than 12 months 12 months or more Total ($ in thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Number of Securities U.S. government agency securities $ — $ — $ 26,254 $ 879 $ 26,254 $ 879 2 State, county and municipals 71,359 1,168 81,418 3,479 152,777 4,647 453 Mortgage-backed securities 32,929 727 93,312 3,940 126,241 4,667 212 Corporate debt securities 69,816 1,132 — — 69,816 1,132 37 Total $ 174,104 $ 3,027 $ 200,984 $ 8,298 $ 375,088 $ 11,325 704 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 Total $ 218,748 $ 2,248 $ 114,863 $ 2,765 $ 333,611 $ 5,013 687
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. September 30, 2018 (in thousands) Amortized Cost Fair Value Due in less than one year $ 21,592 $ 21,559 Due in one year through five years 157,636 154,294 Due after five years through ten years 95,324 92,078 Due after ten years 6,969 7,135 281,521 275,066 Mortgage-backed securities 140,427 135,845 Securities available for sale $ 421,948 $ 410,911
Schedule of proceeds from sale of securities AFS	Proceeds from the sale of securities AFS were as follows. Nine Months Ended September 30, (in thousands) 2018 2017 Gross gains $ — $ 1,227 Gross losses — (7 ) Gains (losses) on sales of securities AFS, net $ — $ 1,220 Proceeds from sales of securities AFS $ — $ 10,798

Loans, Allowance for Loan Los_2

Loans, Allowance for Loan Losses, and Credit Quality (Tables)	9 Months Ended
	Sep. 30, 2018
Receivables [Abstract]
Schedule of loan composition and further breakdown summarized by originated and acquired	The loan composition is summarized as follows. September 30, 2018 December 31, 2017 (in thousands) Amount % of Total Amount % of Total Commercial & industrial $ 665,754 31.1 % $ 637,337 30.5 % Owner-occupied commercial real estate (“CRE”) 449,151 21.0 430,043 20.6 Agricultural (“AG”) production 35,727 1.7 35,455 1.7 AG real estate 52,378 2.4 51,778 2.5 CRE investment 331,312 15.5 314,463 15.1 Construction & land development 86,533 4.0 89,660 4.3 Residential construction 30,295 1.4 36,995 1.8 Residential first mortgage 357,163 16.6 363,352 17.4 Residential junior mortgage 109,692 5.1 106,027 5.1 Retail & other 25,452 1.2 22,815 1.0 Loans 2,143,457 100.0 % 2,087,925 100.0 % Less allowance for loan losses (“ALLL”) 12,992 12,653 Loans, net $ 2,130,465 $ 2,075,272 Allowance for loan losses to loans 0.61 % 0.61 % As a further breakdown, loans are summarized by originated and acquired as follows. September 30, 2018 December 31, 2017 (in thousands) Originated Amount % of Total Acquired Amount % of Total Originated Amount % of Total Acquired Amount % of Total Commercial & industrial $ 551,395 38.9 % $ 114,359 15.8 % $ 488,600 39.3 % $ 148,737 17.6 % Owner-occupied CRE 274,036 19.3 175,115 24.2 237,548 19.1 192,495 22.8 AG production 10,821 0.8 24,906 3.4 11,102 0.9 24,353 2.9 AG real estate 29,685 2.1 22,693 3.1 27,831 2.2 23,947 2.8 CRE investment 151,335 10.7 179,977 24.8 113,862 9.2 200,601 23.8 Construction & land development 63,106 4.4 23,427 3.2 56,061 4.5 33,599 4.0 Residential construction 30,245 2.1 50 0.1 33,615 2.7 3,380 0.4 Residential first mortgage 211,474 14.9 145,689 20.1 191,186 15.4 172,166 20.4 Residential junior mortgage 74,366 5.2 35,326 4.9 65,643 5.3 40,384 4.8 Retail & other 22,464 1.6 2,988 0.4 18,254 1.4 4,561 0.5 Loans 1,418,927 100.0 % 724,530 100.0 % 1,243,702 100.0 % 844,223 100.0 % Less ALLL 11,118 1,874 10,542 2,111 Loans, net $ 1,407,809 $ 722,656 $ 1,233,160 $ 842,112 ALLL to loans 0.78 % 0.26 % 0.85 % 0.25 %
Schedule of roll forward of allowance for loan losses	A roll forward of the allowance for loan losses is summarized as follows. Nine Months Ended Year Ended (in thousands) September 30, 2018 September 30, 2017 December 31, 2017 Beginning balance $ 12,653 $ 11,820 $ 11,820 Provision for loan losses 1,360 1,875 2,325 Charge-offs (1,110 ) (1,156 ) (1,604 ) Recoveries 89 71 112 Net charge-offs (1,021 ) (1,085 ) (1,492 ) Ending balance $ 12,992 $ 12,610 $ 12,653
Schedule of changes in ALLL by portfolio segment and further breakdown summarized by originated and acquired	As a further breakdown, the ALLL is summarized by originated and acquired as follows. Originated – Nine Months Ended September 30, 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 1,143 349 (4 ) 9 (13 ) (217 ) (25 ) 165 (43 ) 247 1,611 Charge-offs (743 ) (64 ) — — (37 ) — — (85 ) — (178 ) (1,107 ) Recoveries 29 1 — — — — — — 29 13 72 Net charge-offs (714 ) (63 ) — — (37 ) — — (85 ) 29 (165 ) (1,035 ) Ending balance $ 4,621 $ 2,401 $ 108 $ 244 $ 1,104 $ 411 $ 175 $ 1,377 $ 395 $ 282 $ 11,118 As percent of ALLL 41.6 % 21.6 % 1.0 % 2.2 % 9.9 % 3.7 % 1.6 % 12.4 % 3.5 % 2.5 % 100.0 % Loans: Individually evaluated $ 2,553 $ 328 $ — $ — $ 918 $ — $ — $ 251 $ — $ — $ 4,050 Collectively evaluated 548,842 273,708 10,821 29,685 150,417 63,106 30,245 211,223 74,366 22,464 1,414,877 Total loans $ 551,395 $ 274,036 $ 10,821 $ 29,685 $ 151,335 $ 63,106 $ 30,245 $ 211,474 $ 74,366 $ 22,464 $ 1,418,927 Less ALLL 4,621 2,401 108 244 1,104 411 175 1,377 395 282 11,118 Net loans $ 546,774 $ 271,635 $ 10,713 $ 29,441 $ 150,231 $ 62,695 $ 30,070 $ 210,097 $ 73,971 $ 22,182 $ 1,407,809 Acquired – Nine Months Ended September 30, 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 (100 ) (56 ) (4 ) (11 ) 5 (13 ) (16 ) (46 ) (12 ) 2 (251 ) Charge-offs — — — — — — — — — (3 ) (3 ) Recoveries 1 11 — — — — — 3 2 — 17 Net charge-offs 1 11 — — — — — 3 2 (3 ) 14 Ending balance $ 643 $ 447 $ 13 $ 50 $ 239 $ 85 $ 35 $ 269 $ 69 $ 24 $ 1,874 As percent of ALLL 34.3 % 23.9 % 0.7 % 2.7 % 12.7 % 4.5 % 1.9 % 14.3 % 3.7 % 1.3 % 100.0 % Loans: Individually evaluated $ 3,305 $ 1,220 $ — $ 234 $ 1,958 $ 603 $ — $ 2,412 $ 57 $ 12 $ 9,801 Collectively evaluated 111,054 173,895 24,906 22,459 178,019 22,824 50 143,277 35,269 2,976 714,729 Total loans $ 114,359 $ 175,115 $ 24,906 $ 22,693 $ 179,977 $ 23,427 $ 50 $ 145,689 $ 35,326 $ 2,988 $ 724,530 Less ALLL 643 447 13 50 239 85 35 269 69 24 1,874 Net loans $ 113,716 $ 174,668 $ 24,893 $ 22,643 $ 179,738 $ 23,342 $ 15 $ 145,420 $ 35,257 $ 2,964 $ 722,656 The following tables present the balance and activity in the ALLL by portfolio segment and the recorded investment in loans by portfolio segment. TOTAL – Nine Months Ended September 30, 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 1,043 293 (8 ) (2 ) (8 ) (230 ) (41 ) 119 (55 ) 249 1,360 Charge-offs (743 ) (64 ) — — (37 ) — — (85 ) — (181 ) (1,110 ) Recoveries 30 12 — — — — — 3 31 13 89 Net charge-offs (713 ) (52 ) — — (37 ) — — (82 ) 31 (168 ) (1,021 ) Ending balance $ 5,264 $ 2,848 $ 121 $ 294 $ 1,343 $ 496 $ 210 $ 1,646 $ 464 $ 306 $ 12,992 As percent of ALLL 40.5 % 21.9 % 0.9 % 2.3 % 10.3 % 3.8 % 1.6 % 12.7 % 3.6 % 2.4 % 100.0 % ALLL: Individually evaluated $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — Collectively evaluated 5,264 2,848 121 294 1,343 496 210 1,646 464 306 12,992 Ending balance $ 5,264 $ 2,848 $ 121 $ 294 $ 1,343 $ 496 $ 210 $ 1,646 $ 464 $ 306 $ 12,992 Loans: Individually evaluated $ 5,858 $ 1,548 $ — $ 234 $ 2,876 $ 603 $ — $ 2,663 $ 57 $ 12 $ 13,851 Collectively evaluated 659,896 447,603 35,727 52,144 328,436 85,930 30,295 354,500 109,635 25,440 2,129,606 Total loans $ 665,754 $ 449,151 $ 35,727 $ 52,378 $ 331,312 $ 86,533 $ 30,295 $ 357,163 $ 109,692 $ 25,452 $ 2,143,457 Less ALLL 5,264 2,848 121 294 1,343 496 210 1,646 464 306 12,992 Net loans $ 660,490 $ 446,303 $ 35,606 $ 52,084 $ 329,969 $ 86,037 $ 30,085 $ 355,517 $ 109,228 $ 25,146 $ 2,130,465 As a further breakdown, the 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 percent 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 percent 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 the balance and activity in the ALLL by portfolio segment and the recorded investment in loans by portfolio segment. 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 percent 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
Schedule of nonaccrual loans by portfolio segment and further breakdown summarized by originated and acquired	The following table presents nonaccrual loans by portfolio segment in total and then as a further breakdown by originated or acquired. Total Nonaccrual Loans (in thousands) September 30, 2018 % of Total December 31, 2017 % of Total Commercial & industrial $ 5,803 57.0 % $ 6,016 46.0 % Owner-occupied CRE 474 4.6 533 4.1 AG production — — — — AG real estate 175 1.7 186 1.4 CRE investment 1,381 13.6 4,531 34.6 Construction & land development 80 0.8 — — Residential construction 28 0.3 80 0.6 Residential first mortgage 1,973 19.4 1,587 12.1 Residential junior mortgage 268 2.6 158 1.2 Retail & other — — 4 — Nonaccrual loans $ 10,182 100.0 % $ 13,095 100.0 % Percent of total loans 0.5 % 0.6 % September 30, 2018 December 31, 2017 (in thousands) Originated Amount % of Total Acquired Amount % of Total Originated Amount % of Total Acquired Amount % of Total Commercial & industrial $ 2,729 55.9 % $ 3,074 58.0 % $ 2,296 70.0 % $ 3,720 37.9 % Owner-occupied CRE 360 7.4 114 2.2 86 2.6 447 4.6 AG production — — — — — — — — AG real estate — — 175 3.3 — — 186 1.9 CRE investment 918 18.8 463 8.7 549 16.8 3,982 40.6 Construction & land development — — 80 1.5 — — — — Residential construction 28 0.6 — — — — 80 0.8 Residential first mortgage 777 15.9 1,196 22.5 331 10.1 1,256 12.8 Residential junior mortgage 66 1.4 202 3.8 12 0.4 146 1.4 Retail & other — — — — 4 0.1 — — Nonaccrual loans $ 4,878 100.0 % $ 5,304 100.0 % $ 3,278 100.0 % $ 9,817 100.0 % Percent of nonaccrual loans 47.9 % 52.1 % 25.0 % 75.0 %
Schedule of past due loans by portfolio segment	The following tables present past due loans by portfolio segment. September 30, 2018 (in thousands) 30-89 Days Past Due (accruing) 90 Days & Over or nonaccrual Current Total Commercial & industrial $ 30 $ 5,803 $ 659,921 $ 665,754 Owner-occupied CRE — 474 448,677 449,151 AG production — — 35,727 35,727 AG real estate 48 175 52,155 52,378 CRE investment — 1,381 329,931 331,312 Construction & land development 104 80 86,349 86,533 Residential construction 212 28 30,055 30,295 Residential first mortgage 638 1,973 354,552 357,163 Residential junior mortgage 31 268 109,393 109,692 Retail & other 61 — 25,391 25,452 Total loans $ 1,124 $ 10,182 $ 2,132,151 $ 2,143,457 Percent of total loans 0.1 % 0.4 % 99.5 % 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 loans by loan grade	The following tables present total loans by risk categories. September 30, 2018 (in thousands) Grades 1- 4 Grade 5 Grade 6 Grade 7 Grade 8 Grade 9 Total Commercial & industrial $ 630,681 $ 20,123 $ 2,725 $ 12,225 $ — $ — $ 665,754 Owner-occupied CRE 412,146 28,643 2,234 6,128 — — 449,151 AG production 30,195 2,892 2,342 298 — — 35,727 AG real estate 45,288 3,483 3,026 581 — — 52,378 CRE investment 321,138 7,086 1,006 2,082 — — 331,312 Construction & land development 81,296 5,141 16 80 — — 86,533 Residential construction 30,267 — — 28 — — 30,295 Residential first mortgage 352,778 1,388 520 2,477 — — 357,163 Residential junior mortgage 109,394 17 — 281 — — 109,692 Retail & other 25,452 — — — — — 25,452 Total loans $ 2,038,635 $ 68,773 $ 11,869 $ 24,180 $ — $ — $ 2,143,457 Percent of total 95.1 % 3.2 % 0.6 % 1.1 % — — 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 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. Total Impaired Loans – September 30, 2018 (in thousands) Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized Commercial & industrial $ 5,858 $ 9,737 $ — $ 6,389 $ 534 Owner-occupied CRE 1,548 2,010 — 1,614 113 AG production — 6 — — 1 AG real estate 234 293 — 238 14 CRE investment 2,876 3,792 — 2,988 294 Construction & land development 603 1,506 — 603 16 Residential construction — — — — — Residential first mortgage 2,663 3,122 — 2,734 159 Residential junior mortgage 57 360 — 62 19 Retail & other 12 13 — 12 1 Total $ 13,851 $ 20,839 $ — $ 14,640 $ 1,151 Originated impaired loans $ 4,050 $ 4,050 $ — $ 4,453 $ 213 Acquired impaired loans 9,801 16,789 — 10,187 938 Total $ 13,851 $ 20,839 $ — $ 14,640 $ 1,151 Total Impaired Loans – 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	Non-accretable discount on purchased credit impaired (“PCI”) loans : Nine Months Ended Year Ended (in thousands) September 30, 2018 September 30, 2017 December 31, 2017 Balance at beginning of period $ 9,471 $ 14,327 $ 14,327 Acquired balance, net — 8,352 8,352 Accretion to loan interest income (1,872 ) (5,925 ) (7,995 ) Transferred to accretable (513 ) — (1,936 ) Disposals of loans (97 ) (1,121 ) (3,277 ) Balance at end of period $ 6,989 $ 15,633 $ 9,471

Goodwill and Other Intangible_2

Goodwill and Other Intangibles and Mortgage Servicing Rights (Tables)	9 Months Ended
	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of goodwill and intangible assets included in other assets	The Company’s quarterly assessment indicated no impairment charge on goodwill, core deposit intangibles or customer list intangibles was required for the year ended December 31, 2017 or the nine months ended September 30, 2018 . Nine Months Ended Year Ended (in thousands) September 30, 2018 December 31, 2017 Goodwill $ 107,366 $ 107,366 Core deposit intangibles 13,488 16,477 Customer list intangibles 4,506 4,563 Other intangibles 17,994 21,040 Goodwill and other intangibles, net $ 125,360 $ 128,406
Schedule of other intangible assets	uring 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 2 for additional information on Nicolet's acquisitions. Nine Months Ended Year Ended (in thousands) September 30, 2018 December 31, 2017 Core deposit intangibles: Gross carrying amount $ 29,015 $ 29,015 Accumulated amortization (15,527 ) (12,538 ) Net book value $ 13,488 $ 16,477 Additions during the period $ — $ 3,670 Amortization during the period $ 2,989 $ 4,294 Customer list intangibles: Gross carrying amount $ 5,523 $ 5,233 Accumulated amortization (1,017 ) (670 ) Net book value $ 4,506 $ 4,563 Additions during the period $ 290 $ 870 Amortization during the period $ 347 $ 401
Schedule of mortgage servicing rights	Activity in the mortgage servicing rights asset was as follows. Nine Months Ended Year Ended (in thousands) September 30, 2018 December 31, 2017 Mortgage servicing rights (MSR) asset: MSR asset at beginning of year $ 3,187 $ 1,922 Capitalized MSR 696 876 MSR asset acquired — 874 Amortization during the period (464 ) (485 ) MSR asset at end of period $ 3,419 $ 3,187 Fair value of MSR asset at end of period $ 4,304 $ 4,097 Residential mortgage loans serviced for others $ 560,607 $ 518,419 Net book value of MSR asset to loans serviced for others 0.61 % 0.61 %
Schedule of estimated future amortization expense for amortizing intangible assets and 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 the September 30, 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 Year ending December 31, 2018 (remaining three months) $ 926 $ 127 $ 161 2019 3,337 507 643 2020 2,657 507 814 2021 2,167 507 381 2022 1,735 507 381 Thereafter 2,666 2,351 1,039 Total $ 13,488 $ 4,506 $ 3,419

Short and Long-Term Borrowings

Short and Long-Term Borrowings (Tables)	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Schedule of components of long-term borrowings	The components of long-term borrowings (borrowing with an original maturity greater than one year) were as follows. (in thousands) September 30, 2018 December 31, 2017 FHLB advances $ 35,317 $ 36,509 Junior subordinated debentures 29,976 29,616 Subordinated notes 11,948 11,921 Total long-term borrowings $ 77,241 $ 78,046
Schedule of junior subordinated debentures	At September 30, 2018 and December 31, 2017 , $28.8 million and $28.5 million , respectively, qualify as Tier 1 capital. Junior Subordinated Debentures (in thousands) Maturity Date Par 9/30/2018 Unamortized Discount 9/30/2018 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 (3,421 ) 6,889 6,739 2006 Baylake Corp. (3) 9/30/2036 16,598 (4,179 ) 12,419 12,242 2004 First Menasha Bancshares, Inc. (4) 3/17/2034 5,155 (673 ) 4,482 4,449 Total $ 38,249 $ (8,273 ) $ 29,976 $ 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 3.76% and 3.02% as of September 30, 2018 and December 31, 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 3.75% and 3.04% as of September 30, 2018 and December 31, 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 rates were 5.12% and 4.39% as of September 30, 2018 and December 31, 2017 , respectively.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 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 September 30, 2018 U.S. government agency securities $ 26,254 $ — $ 26,254 $ — State, county and municipals 164,822 — 164,756 66 Mortgage-backed securities 135,845 — 135,845 — Corporate debt securities 83,990 — 75,552 8,438 Securities AFS $ 410,911 $ — $ 402,407 $ 8,504 Other investments (equity securities) * $ 2,778 $ 2,778 $ — $ — 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 $2.8 million current fair value of equity securities is now reflected within other investments on the consolidated balance sheets instead of in securities AFS at December 31, 2017. 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 5 for additional information on the impact to securities AFS.
Schedule of changes in the Level 3 securities AFS measured at fair value on a recurring basis	The following table presents the changes in the Level 3 securities AFS measured at fair value on a recurring basis. (in thousands) Nine Months Ended Year Ended Level 3 Fair Value Measurements: September 30, 2018 December 31, 2017 Balance at beginning of year $ 9,151 $ 9,108 Acquired balance — 189 Paydowns/Sales/Settlements (647 ) (146 ) Balance at end of period $ 8,504 $ 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 for the periods presented, aggregated by 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 September 30, 2018 Impaired loans $ 13,851 $ — $ — $ 13,851 Other real estate owned (“OREO”) 1,281 — — 1,281 MSR asset 4,304 — — 4,304 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. September 30, 2018 (in thousands) Carrying Amount Estimated Fair Value Level 1 Level 2 Level 3 Financial assets: Cash and cash equivalents $ 161,155 $ 161,155 $ 161,155 $ — $ — Certificates of deposit in other banks 995 995 — 995 — Securities AFS 410,911 410,911 — 402,407 8,504 Other investments, including equity securities 17,479 17,479 2,778 13,117 1,584 Loans held for sale 2,593 2,643 — 2,643 — Loans, net 2,130,465 2,103,456 — — 2,103,456 BOLI 65,820 65,820 65,820 — — MSR asset 3,419 4,304 — — 4,304 Financial liabilities: Deposits $ 2,522,156 $ 2,523,832 $ — $ — $ 2,523,832 Long-term borrowings 77,241 76,198 — 35,300 40,898 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

Basis of Presentation (Detail T

Basis of Presentation (Detail Textuals)	9 Months Ended
	Sep. 30, 2018Segment
Accounting Policies [Abstract]
Number of operating segments	1

Acquisitions (Detail Textuals)

Acquisitions (Detail Textuals)	May 01, 2017Branch	Apr. 28, 2017USD ($)$ / sharesshares	Sep. 30, 2018USD ($)
Customer Lists
Business Acquisitions [Line Items]
Intangible assets assumed			$ 290,000
Merger Agreement (the "Merger Agreement") | First Menasha Bancshares, Inc. ("First Menasha")
Business Acquisitions [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
Value of common stock issued for consideration		$ 62,200,000
Price per share for stock issued in consideration | $ / shares		$ 47.52
Number of trading days		20 days
Value of cash consideration		$ 19,300,000
Direct stock issuance costs for the merger charged against additional paid in capital		200,000
Amount of addition in assets		480,000,000
Amount of addition in loans		351,000,000
Amount of addition in deposit		375,000,000
Amount of addition in goodwill		41,000,000
Merger Agreement (the "Merger Agreement") | First Menasha Bancshares, Inc. ("First Menasha") | Core deposit intangibles
Business Acquisitions [Line Items]
Intangible assets assumed		$ 4,000,000

Earnings per Common Share - Cal

Earnings per Common Share - Calculations for basic and diluted earnings (loss) per common share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Earnings Per Share [Abstract]
Net income attributable to Nicolet Bankshares, Inc.	$ 10,859	$ 9,511	$ 30,173	$ 24,047
Weighted average common shares outstanding (in shares)	9,633,158	9,836,646	9,678,726	9,316,814
Effect of dilutive common stock awards (in shares)	316,000	572,000	325,000	504,000
Diluted weighted average common shares outstanding (in shares)	9,949,295	10,408,683	10,004,316	9,820,724
Basic earnings per common share (in dollars per share)	$ 1.13	$ 0.97	$ 3.12	$ 2.58
Diluted earnings per common share (in dollars per share)	$ 1.09	$ 0.91	$ 3.02	$ 2.45

Earnings per Common Share (Deta

Earnings per Common Share (Detail Textuals) - shares shares in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Earnings Per Share [Abstract]
Shares excluded from calculation of earnings per common share	0.1	0.1

Stock-based Compensation - Weig

Stock-based Compensation - Weighted average assumptions (Details) - Stock Incentive Plan - Stock Options - $ / shares	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	0.00%	0.00%
Expected volatility	25.00%	25.00%
Risk-free interest rate	2.48%	2.13%
Expected average life (in years)	7 years	7 years
Weighted average per share fair value of options	$ 17.60	$ 15.44

Stock-based Compensation - Acti

Stock-based Compensation - Activity of stock incentive plans for options (Details 1) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Options Shares Outstanding
Forfeited (in shares)	(2,194)
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value	$ 1,800	$ 1,800
Stock Incentive Plan | Stock Options
Options Shares Outstanding
Outstanding - December 31, 2017 (in shares)	1,643,255
Granted (in shares)	10,000
Exercise of stock options (in shares)	(56,881)
Forfeited (in shares)	(6,500)
Outstanding - September 30, 2018 (in shares)	1,589,874
Exercisable - September 30, 2018 (in shares)	543,886
Weighted-Average Exercise Price
Outstanding - December 31, 2017 (in dollars per share)	$ 39.82
Granted (in dollars per share)	54.06
Exercise of stock options (in dollars per share)	21.53
Forfeited (in dollars per share)	39.43
Outstanding - September 30, 2018 (in dollars per share)	40.57
Exercisable - September 30, 2018 (in dollars per share)	$ 32
Weighted Average Remaining Life (Years) Outstanding	7 years 7 months 7 days
Weighted Average Remaining Life (Years) Exercisable	6 years 4 months 24 days
Aggregate Intrinsic Value Outstanding	$ 22,429
Aggregate Intrinsic Value Exercisable	$ 12,243

Stock-based Compensation - Ac_2

Stock-based Compensation - Activity of restricted stock awards (Details 2) - Restricted Stock	9 Months Ended
	Sep. 30, 2018$ / sharesshares
Weighted-Average Grant Date Fair Value
Outstanding - December 31, 2017 (in dollars per share) | $ / shares	$ 34.26
Granted (in dollars per share) | $ / shares	55.64
Vested (in dollars per share) | $ / shares	37.44
Forfeited (in dollars per share) | $ / shares	(16.50)
Outstanding - September 30, 2018 (in dollars per share) | $ / shares	$ 38.84
Restricted Shares Outstanding
Outstanding - December 31, 2017 (in shares) | shares	30,920
Granted (in shares) | shares	7,510
Vested (in shares) | shares	(10,911)
Forfeited (in shares) | shares	(3)
Outstanding - September 30, 2018 (in shares) | shares	27,516

Stock-based Compensation (Detai

Stock-based Compensation (Detail Textuals) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based employee compensation		$ 3.4	$ 1.9
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total intrinsic value of options exercised		$ 1.8	$ 1.8
Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based employee compensation	$ 0.2
Stock-based employee compensation, shares issued		3,510

Stock-based Compensation (Det_2

Stock-based Compensation (Detail Textuals 1) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares were available for grant under two plans	144,000	144,000
Numbers of shares surrendered (in shares)		1,615
Stock-based employee compensation		$ 3.4	$ 1.9
Unrecognized compensation cost	$ 13.7	$ 13.7
Remaining vesting period over which cost expected to be recognized		3 years
Employee service share-based compensation, Tax benefit from compensation expense		$ 0.2	$ 0.2
Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based employee compensation	$ 0.2

Securities Available for Sale -

Securities Available for Sale - Amortized costs and fair values of debt securities available for sale (Details) - USD ($)	Jan. 01, 2018	Sep. 30, 2018	Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		$ 421,948,000
Fair Value		410,911,000
Current fair value of equity securities moved out of available-for-sale securities		17,479,000	$ 14,837,000
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		140,427,000
Fair Value		135,845,000
Accounting Standards Update 2016-01
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		421,948,000	408,093,000
Gross Unrealized Gains		288,000	2,073,000
Gross Unrealized Losses		11,325,000	5,013,000
Fair Value		410,911,000	405,153,000
Cumulative-effect adjustment for after tax impact on retained earnings		475,000
Current fair value of equity securities moved out of available-for-sale securities		2,800,000
Current fair value of equity securities included within other investments		(2,800,000)
Accounting Standards Update 2016-01 | U.S. government agency securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		27,133,000	26,586,000
Gross Unrealized Gains		0	0
Gross Unrealized Losses		879,000	377,000
Fair Value		26,254,000	26,209,000
Accounting Standards Update 2016-01 | State, county and municipals
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		169,431,000	186,128,000
Gross Unrealized Gains		38,000	180,000
Gross Unrealized Losses		4,647,000	2,264,000
Fair Value		164,822,000	184,044,000
Accounting Standards Update 2016-01 | Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		140,427,000	157,705,000
Gross Unrealized Gains		85,000	160,000
Gross Unrealized Losses		4,667,000	2,333,000
Fair Value		135,845,000	155,532,000
Accounting Standards Update 2016-01 | Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		84,957,000	36,387,000
Gross Unrealized Gains		165,000	449,000
Gross Unrealized Losses		1,132,000	39,000
Fair Value		$ 83,990,000	36,797,000
Retained Earnings
Schedule of Available-for-sale Securities [Line Items]
Cumulative effect adjustment for after tax impact on other comprehensive income	$ 900,000
Retained Earnings | Accounting Standards Update 2016-01
Schedule of Available-for-sale Securities [Line Items]
Cumulative-effect adjustment for after tax impact of unrealized gain on equity securities			$ 937,000

Securities Available for Sale_2

Securities Available for Sale - Amortized costs and fair values of equity securities available for sale (Details 1) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 421,948
Fair Value	410,911
Mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	140,427
Fair Value	135,845
Accounting Standards Update 2016-01
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	421,948	$ 408,093
Gross Unrealized Gains	288	2,073
Gross Unrealized Losses	11,325	5,013
Fair Value	410,911	405,153
Accounting Standards Update 2016-01 | U.S. government agency securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	27,133	26,586
Gross Unrealized Gains	0	0
Gross Unrealized Losses	879	377
Fair Value	26,254	26,209
Accounting Standards Update 2016-01 | State, county and municipals
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	169,431	186,128
Gross Unrealized Gains	38	180
Gross Unrealized Losses	4,647	2,264
Fair Value	164,822	184,044
Accounting Standards Update 2016-01 | Mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	140,427	157,705
Gross Unrealized Gains	85	160
Gross Unrealized Losses	4,667	2,333
Fair Value	135,845	155,532
Accounting Standards Update 2016-01 | Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	84,957	36,387
Gross Unrealized Gains	165	449
Gross Unrealized Losses	1,132	39
Fair Value	$ 83,990	$ 36,797

Securities Available for Sale_3

Securities Available for Sale - Amortized costs and fair values of debt and equity securities available for sale (Details 2) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Fair Value	$ 410,911
Amortized Cost	421,948
Mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	135,845
Amortized Cost	140,427
Accounting Standards Update 2016-01
Debt Securities, Available-for-sale [Line Items]
Fair Value	410,911	$ 405,153
Amortized Cost	421,948	408,093
Gross Unrealized Gains	288	2,073
Gross Unrealized Losses	11,325	5,013
Accounting Standards Update 2016-01 | U.S. government agency securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	26,254	26,209
Amortized Cost	27,133	26,586
Gross Unrealized Gains	0	0
Gross Unrealized Losses	879	377
Accounting Standards Update 2016-01 | State, county and municipals
Debt Securities, Available-for-sale [Line Items]
Fair Value	164,822	184,044
Amortized Cost	169,431	186,128
Gross Unrealized Gains	38	180
Gross Unrealized Losses	4,647	2,264
Accounting Standards Update 2016-01 | Mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	135,845	155,532
Amortized Cost	140,427	157,705
Gross Unrealized Gains	85	160
Gross Unrealized Losses	4,667	2,333
Accounting Standards Update 2016-01 | Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	83,990	36,797
Amortized Cost	84,957	36,387
Gross Unrealized Gains	165	449
Gross Unrealized Losses	$ 1,132	39
Accounting Standards Update 2016-01 | Equity Securities
Debt Securities, Available-for-sale [Line Items]
Fair Value		2,571
Amortized Cost		1,287
Gross Unrealized Gains		1,284
Gross Unrealized Losses		$ 0

Securities Available for Sale_4

Securities Available for Sale - Gross unrealized losses and the related fair value of securities available for sale (Details 3) - Accounting Standards Update 2016-01 $ in Thousands	Sep. 30, 2018USD ($)Security	Dec. 31, 2017USD ($)Security
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	$ 174,104	$ 218,748
Less than 12 months, Unrealized Losses	3,027	2,248
12 months or more, Fair Value	200,984	114,863
12 months or more, Unrealized Losses	8,298	2,765
Total, Fair Value	375,088	333,611
Total, Unrealized Losses	$ 11,325	$ 5,013
Number of securities | Security	704	687
U.S. government agency securities
Schedule of Available-for-sale Securities [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	26,254	0
12 months or more, Unrealized Losses	879	0
Total, Fair Value	26,254	26,209
Total, Unrealized Losses	$ 879	$ 377
Number of securities | Security	2	2
State, county and municipals
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	$ 71,359	$ 110,157
Less than 12 months, Unrealized Losses	1,168	1,097
12 months or more, Fair Value	81,418	49,326
12 months or more, Unrealized Losses	3,479	1,167
Total, Fair Value	152,777	159,483
Total, Unrealized Losses	$ 4,647	$ 2,264
Number of securities | Security	453	465
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	$ 32,929	$ 72,210
Less than 12 months, Unrealized Losses	727	735
12 months or more, Fair Value	93,312	65,537
12 months or more, Unrealized Losses	3,940	1,598
Total, Fair Value	126,241	137,747
Total, Unrealized Losses	$ 4,667	$ 2,333
Number of securities | Security	212	215
Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	$ 69,816	$ 10,172
Less than 12 months, Unrealized Losses	1,132	39
12 months or more, Fair Value	0	0
12 months or more, Unrealized Losses	0	0
Total, Fair Value	69,816	10,172
Total, Unrealized Losses	$ 1,132	$ 39
Number of securities | Security	37	5

Securities Available for Sale_5

Securities Available for Sale - Amortized cost and fair values of securities available for sale at by contractual maturity (Details 4) $ in Thousands	Sep. 30, 2018USD ($)
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Due in less than one year	$ 21,592
Amortized Cost, Due in one year through five years	157,636
Amortized Cost, Due after five years through ten years	95,324
Amortized Cost, Due after ten years	6,969
Single maturity date, Amortized Cost	281,521
Amortized Cost	421,948
Fair Value, Due in less than one year	21,559
Fair Value, Due in one year through five years	154,294
Fair Value, Due after five years through ten years	92,078
Fair Value, Due after ten years	7,135
Single maturity date, Fair value	275,066
Fair Value	410,911
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	140,427
Fair Value	$ 135,845

Securities Available for Sale_6

Securities Available for Sale - Proceeds from the sale of securities (Details 5) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Debt Securities, Available-for-sale [Abstract]
Debt Securities, Available-for-sale, Realized Gain	$ 0	$ 1,227
Debt Securities, Available-for-sale, Realized Loss	0	(7)
Debt Securities, Available-for-sale, Realized Gain (Loss)	0	1,220
Proceeds from Sale of Debt Securities, Available-for-sale	$ 0	$ 10,798

Loans, Allowance for Loan Los_3

Loans, Allowance for Loan Losses, and Credit Quality - Summary of loan composition (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 2,143,457	$ 2,087,925
Less allowance for loan losses (“ALLL”)	12,992	12,653	$ 12,610	$ 11,820
Loans, net	$ 2,130,465	$ 2,075,272
% of Total	100.00%	100.00%
Allowance for loan losses to loans	0.61%	0.61%
Retail & other
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 25,452	$ 22,815
Less allowance for loan losses (“ALLL”)	306	225		152
Loans, net	$ 25,146	$ 22,590
% of Total	1.20%	1.00%
Commercial Portfolio Segment | Commercial & industrial
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 665,754	$ 637,337
Less allowance for loan losses (“ALLL”)	5,264	4,934		3,919
Loans, net	$ 660,490	$ 632,403
% of Total	31.10%	30.50%
Commercial Portfolio Segment | Owner-occupied CRE
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 449,151	$ 430,043
Less allowance for loan losses (“ALLL”)	2,848	2,607		2,867
Loans, net	$ 446,303	$ 427,436
% of Total	21.00%	20.60%
Commercial Portfolio Segment | AG production
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 35,727	$ 35,455
Less allowance for loan losses (“ALLL”)	121	129		150
Loans, net	$ 35,606	$ 35,326
% of Total	1.70%	1.70%
Commercial Real Estate Portfolio Segment | AG real estate
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 52,378	$ 51,778
Less allowance for loan losses (“ALLL”)	294	296		285
Loans, net	$ 52,084	$ 51,482
% of Total	2.40%	2.50%
Commercial Real Estate Portfolio Segment | CRE investment
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 331,312	$ 314,463
Less allowance for loan losses (“ALLL”)	1,343	1,388		1,124
Loans, net	$ 329,969	$ 313,075
% of Total	15.50%	15.10%
Commercial Real Estate Portfolio Segment | Construction & land development
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 86,533	$ 89,660
Less allowance for loan losses (“ALLL”)	496	726		774
Loans, net	$ 86,037	$ 88,934
% of Total	4.00%	4.30%
Residential | Residential construction
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 30,295	$ 36,995
Less allowance for loan losses (“ALLL”)	210	251		304
Loans, net	$ 30,085	$ 36,744
% of Total	1.40%	1.80%
Residential | Residential first mortgage
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 357,163	$ 363,352
Less allowance for loan losses (“ALLL”)	1,646	1,609		1,784
Loans, net	$ 355,517	$ 361,743
% of Total	16.60%	17.40%
Residential | Residential junior mortgage
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 109,692	$ 106,027
Less allowance for loan losses (“ALLL”)	464	488		461
Loans, net	$ 109,228	$ 105,539
% of Total	5.10%	5.10%
Originated
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 1,418,927	$ 1,243,702
Less allowance for loan losses (“ALLL”)	11,118	10,542		9,449
Loans, net	$ 1,407,809	$ 1,233,160
% of Total	100.00%	100.00%
Allowance for loan losses to loans	0.78%	0.85%
Originated | Retail & other
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 22,464	$ 18,254
Less allowance for loan losses (“ALLL”)	282	200		132
Loans, net	$ 22,182	$ 18,054
% of Total	1.60%	1.40%
Originated | Commercial Portfolio Segment | Commercial & industrial
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 551,395	$ 488,600
Less allowance for loan losses (“ALLL”)	4,621	4,192		3,150
Loans, net	$ 546,774	$ 484,408
% of Total	38.90%	39.30%
Originated | Commercial Portfolio Segment | Owner-occupied CRE
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 274,036	$ 237,548
Less allowance for loan losses (“ALLL”)	2,401	2,115		2,263
Loans, net	$ 271,635	$ 235,433
% of Total	19.30%	19.10%
Originated | Commercial Portfolio Segment | AG production
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 10,821	$ 11,102
Less allowance for loan losses (“ALLL”)	108	112		122
Loans, net	$ 10,713	$ 10,990
% of Total	0.80%	0.90%
Originated | Commercial Real Estate Portfolio Segment | AG real estate
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 29,685	$ 27,831
Less allowance for loan losses (“ALLL”)	244	235		222
Loans, net	$ 29,441	$ 27,596
% of Total	2.10%	2.20%
Originated | Commercial Real Estate Portfolio Segment | CRE investment
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 151,335	$ 113,862
Less allowance for loan losses (“ALLL”)	1,104	1,154		893
Loans, net	$ 150,231	$ 112,708
% of Total	10.70%	9.20%
Originated | Commercial Real Estate Portfolio Segment | Construction & land development
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 63,106	$ 56,061
Less allowance for loan losses (“ALLL”)	411	628		656
Loans, net	$ 62,695	$ 55,433
% of Total	4.40%	4.50%
Originated | Residential | Residential construction
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 30,245	$ 33,615
Less allowance for loan losses (“ALLL”)	175	200		266
Loans, net	$ 30,070	$ 33,415
% of Total	2.10%	2.70%
Originated | Residential | Residential first mortgage
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 211,474	$ 191,186
Less allowance for loan losses (“ALLL”)	1,377	1,297		1,372
Loans, net	$ 210,097	$ 189,889
% of Total	14.90%	15.40%
Originated | Residential | Residential junior mortgage
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 74,366	$ 65,643
Less allowance for loan losses (“ALLL”)	395	409		373
Loans, net	$ 73,971	$ 65,234
% of Total	5.20%	5.30%
Acquired
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 724,530	$ 844,223
Less allowance for loan losses (“ALLL”)	1,874	2,111		2,371
Loans, net	$ 722,656	$ 842,112
% of Total	100.00%	100.00%
Allowance for loan losses to loans	0.26%	0.25%
Acquired | Retail & other
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 2,988	$ 4,561
Less allowance for loan losses (“ALLL”)	24	25		20
Loans, net	$ 2,964	$ 4,536
% of Total	0.40%	0.50%
Acquired | Commercial Portfolio Segment | Commercial & industrial
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 114,359	$ 148,737
Less allowance for loan losses (“ALLL”)	643	742		769
Loans, net	$ 113,716	$ 147,995
% of Total	15.80%	17.60%
Acquired | Commercial Portfolio Segment | Owner-occupied CRE
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 175,115	$ 192,495
Less allowance for loan losses (“ALLL”)	447	492		604
Loans, net	$ 174,668	$ 192,003
% of Total	24.20%	22.80%
Acquired | Commercial Portfolio Segment | AG production
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 24,906	$ 24,353
Less allowance for loan losses (“ALLL”)	13	17		28
Loans, net	$ 24,893	$ 24,336
% of Total	3.40%	2.90%
Acquired | Commercial Real Estate Portfolio Segment | AG real estate
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 22,693	$ 23,947
Less allowance for loan losses (“ALLL”)	50	61		63
Loans, net	$ 22,643	$ 23,886
% of Total	3.10%	2.80%
Acquired | Commercial Real Estate Portfolio Segment | CRE investment
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 179,977	$ 200,601
Less allowance for loan losses (“ALLL”)	239	234		231
Loans, net	$ 179,738	$ 200,367
% of Total	24.80%	23.80%
Acquired | Commercial Real Estate Portfolio Segment | Construction & land development
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 23,427	$ 33,599
Less allowance for loan losses (“ALLL”)	85	98		118
Loans, net	$ 23,342	$ 33,501
% of Total	3.20%	4.00%
Acquired | Residential | Residential construction
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 50	$ 3,380
Less allowance for loan losses (“ALLL”)	35	51		38
Loans, net	$ 15	$ 3,329
% of Total	0.10%	0.40%
Acquired | Residential | Residential first mortgage
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 145,689	$ 172,166
Less allowance for loan losses (“ALLL”)	269	312		412
Loans, net	$ 145,420	$ 171,854
% of Total	20.10%	20.40%
Acquired | Residential | Residential junior mortgage
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 35,326	$ 40,384
Less allowance for loan losses (“ALLL”)	69	79		$ 88
Loans, net	$ 35,257	$ 40,305
% of Total	4.90%	4.80%

Loans, Allowance for Loan Los_4

Loans, Allowance for Loan Losses, and Credit Quality - Summary of allowance for loan losses (Details 1) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 12,653	$ 11,820	$ 11,820
Provision for loan losses	1,360	1,875	2,325
Charge-offs	(1,110)	(1,156)	(1,604)
Recoveries	89	71	112
Net charge-offs	(1,021)	(1,085)	(1,492)
Ending balance	$ 12,992	$ 12,610	$ 12,653

Loans, Allowance for Loan Los_5

Loans, Allowance for Loan Losses, and Credit Quality - Summary of changes in ALLL by portfolio segment for periods - Allowance for Loan Losses (Details 2) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 13,851		$ 17,221
Allowance for Loan Losses (ALLL):
Beginning balance	12,653	$ 11,820	11,820
Provision	1,360	1,875	2,325
Charge-offs	(1,110)	(1,156)	(1,604)
Recoveries	89	71	112
Net charge-offs	(1,021)	(1,085)	(1,492)
Ending balance	$ 12,992	12,610	$ 12,653
As percent of ALLL	100.00%		100.00%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	$ 0		$ 163
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	12,992		12,490
Retail & other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	12		12
Allowance for Loan Losses (ALLL):
Beginning balance	225	152	152
Provision	249		127
Charge-offs	(181)		(69)
Recoveries	13		15
Net charge-offs	(168)		(54)
Ending balance	$ 306		$ 225
As percent of ALLL	2.40%		1.80%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	$ 0		$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	306		225
Commercial Portfolio Segment | Commercial & industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	5,858		5,870
Allowance for Loan Losses (ALLL):
Beginning balance	4,934	3,919	3,919
Provision	1,043		2,419
Charge-offs	(743)		(1,442)
Recoveries	30		38
Net charge-offs	(713)		(1,404)
Ending balance	$ 5,264		$ 4,934
As percent of ALLL	40.50%		39.00%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	$ 0		$ 163
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	5,264		4,771
Commercial Portfolio Segment | Owner-occupied CRE
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	1,548		1,689
Allowance for Loan Losses (ALLL):
Beginning balance	2,607	2,867	2,867
Provision	293		(290)
Charge-offs	(64)		0
Recoveries	12		30
Net charge-offs	(52)		30
Ending balance	$ 2,848		$ 2,607
As percent of ALLL	21.90%		20.60%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	$ 0		$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	2,848		2,607
Commercial Portfolio Segment | AG Production
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	0		0
Allowance for Loan Losses (ALLL):
Beginning balance	129	150	150
Provision	(8)		(21)
Charge-offs	0		0
Recoveries	0		0
Net charge-offs	0		0
Ending balance	$ 121		$ 129
As percent of ALLL	0.90%		1.00%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	$ 0		$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	121		129
Commercial Real Estate Portfolio Segment | AG real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	234		248
Allowance for Loan Losses (ALLL):
Beginning balance	296	285	285
Provision	(2)		11
Charge-offs	0		0
Recoveries	0		0
Net charge-offs	0		0
Ending balance	$ 294		$ 296
As percent of ALLL	2.30%		2.30%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	$ 0		$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	294		296
Commercial Real Estate Portfolio Segment | CRE investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	2,876		5,290
Allowance for Loan Losses (ALLL):
Beginning balance	1,388	1,124	1,124
Provision	(8)		263
Charge-offs	(37)		0
Recoveries	0		1
Net charge-offs	(37)		1
Ending balance	$ 1,343		$ 1,388
As percent of ALLL	10.30%		11.00%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	$ 0		$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	1,343		1,388
Commercial Real Estate Portfolio Segment | Construction & land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	603		1,053
Allowance for Loan Losses (ALLL):
Beginning balance	726	774	774
Provision	(230)		(35)
Charge-offs	0		(13)
Recoveries	0		0
Net charge-offs	0		(13)
Ending balance	$ 496		$ 726
As percent of ALLL	3.80%		5.70%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	$ 0		$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	496		726
Residential | Residential first mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	2,663		2,801
Allowance for Loan Losses (ALLL):
Beginning balance	1,609	1,784	1,784
Provision	119		(192)
Charge-offs	(85)		(8)
Recoveries	3		25
Net charge-offs	(82)		17
Ending balance	$ 1,646		$ 1,609
As percent of ALLL	12.70%		12.70%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	$ 0		$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	1,646		1,609
Residential | Residential junior mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	57		178
Allowance for Loan Losses (ALLL):
Beginning balance	488	461	461
Provision	(55)		96
Charge-offs	0		(72)
Recoveries	31		3
Net charge-offs	31		(69)
Ending balance	$ 464		$ 488
As percent of ALLL	3.60%		3.90%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	$ 0		$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	464		488
Residential | Residential construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	0		80
Allowance for Loan Losses (ALLL):
Beginning balance	251	304	304
Provision	(41)		(53)
Charge-offs	0		0
Recoveries	0		0
Net charge-offs	0		0
Ending balance	$ 210		$ 251
As percent of ALLL	1.60%		2.00%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	$ 0		$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	210		251
Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	4,050		3,003
Allowance for Loan Losses (ALLL):
Beginning balance	10,542	9,449	9,449
Provision	1,611		2,585
Charge-offs	(1,107)		(1,537)
Recoveries	72		45
Net charge-offs	(1,035)		(1,492)
Ending balance	$ 11,118		$ 10,542
As percent of ALLL	100.00%		100.00%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			$ 163
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			10,379
Originated | Retail & other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 0		0
Allowance for Loan Losses (ALLL):
Beginning balance	200	132	132
Provision	247		122
Charge-offs	(178)		(69)
Recoveries	13		15
Net charge-offs	(165)		(54)
Ending balance	$ 282		$ 200
As percent of ALLL	2.50%		1.80%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			200
Originated | Commercial Portfolio Segment | Commercial & industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 2,553		2,189
Allowance for Loan Losses (ALLL):
Beginning balance	4,192	3,150	3,150
Provision	1,143		2,429
Charge-offs	(743)		(1,388)
Recoveries	29		1
Net charge-offs	(714)		(1,387)
Ending balance	$ 4,621		$ 4,192
As percent of ALLL	41.60%		39.80%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			$ 163
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			4,029
Originated | Commercial Portfolio Segment | Owner-occupied CRE
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 328		0
Allowance for Loan Losses (ALLL):
Beginning balance	2,115	2,263	2,263
Provision	349		(172)
Charge-offs	(64)		0
Recoveries	1		24
Net charge-offs	(63)		24
Ending balance	$ 2,401		$ 2,115
As percent of ALLL	21.60%		20.10%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			2,115
Originated | Commercial Portfolio Segment | AG Production
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 0		0
Allowance for Loan Losses (ALLL):
Beginning balance	112	122	122
Provision	(4)		(10)
Charge-offs	0		0
Recoveries	0		0
Net charge-offs	0		0
Ending balance	$ 108		$ 112
As percent of ALLL	1.00%		1.10%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			112
Originated | Commercial Real Estate Portfolio Segment | AG real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 0		0
Allowance for Loan Losses (ALLL):
Beginning balance	235	222	222
Provision	9		13
Charge-offs	0		0
Recoveries	0		0
Net charge-offs	0		0
Ending balance	$ 244		$ 235
As percent of ALLL	2.20%		2.20%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			235
Originated | Commercial Real Estate Portfolio Segment | CRE investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 918		549
Allowance for Loan Losses (ALLL):
Beginning balance	1,154	893	893
Provision	(13)		261
Charge-offs	(37)		0
Recoveries	0		0
Net charge-offs	(37)		0
Ending balance	$ 1,104		$ 1,154
As percent of ALLL	9.90%		10.90%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			1,154
Originated | Commercial Real Estate Portfolio Segment | Construction & land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 0		0
Allowance for Loan Losses (ALLL):
Beginning balance	628	656	656
Provision	(217)		(28)
Charge-offs	0		0
Recoveries	0		0
Net charge-offs	0		0
Ending balance	$ 411		$ 628
As percent of ALLL	3.70%		6.00%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			628
Originated | Residential | Residential first mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 251		253
Allowance for Loan Losses (ALLL):
Beginning balance	1,297	1,372	1,372
Provision	165		(69)
Charge-offs	(85)		(8)
Recoveries	0		2
Net charge-offs	(85)		(6)
Ending balance	$ 1,377		$ 1,297
As percent of ALLL	12.40%		12.30%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			1,297
Originated | Residential | Residential junior mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 0		12
Allowance for Loan Losses (ALLL):
Beginning balance	409	373	373
Provision	(43)		105
Charge-offs	0		(72)
Recoveries	29		3
Net charge-offs	29		(69)
Ending balance	$ 395		$ 409
As percent of ALLL	3.50%		3.90%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			409
Originated | Residential | Residential construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 0		0
Allowance for Loan Losses (ALLL):
Beginning balance	200	266	266
Provision	(25)		(66)
Charge-offs	0		0
Recoveries	0		0
Net charge-offs	0		0
Ending balance	$ 175		$ 200
As percent of ALLL	1.60%		1.90%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			200
Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 9,801		14,218
Allowance for Loan Losses (ALLL):
Beginning balance	2,111	2,371	2,371
Provision	(251)		(260)
Charge-offs	(3)		(67)
Recoveries	17		67
Net charge-offs	14		0
Ending balance	$ 1,874		$ 2,111
As percent of ALLL	100.00%		100.00%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			2,111
Acquired | Retail & other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 12		12
Allowance for Loan Losses (ALLL):
Beginning balance	25	20	20
Provision	2		5
Charge-offs	(3)		0
Recoveries	0		0
Net charge-offs	(3)		0
Ending balance	$ 24		$ 25
As percent of ALLL	1.30%		1.30%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			25
Acquired | Commercial Portfolio Segment | Commercial & industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 3,305		3,681
Allowance for Loan Losses (ALLL):
Beginning balance	742	769	769
Provision	(100)		(10)
Charge-offs	0		(54)
Recoveries	1		37
Net charge-offs	1		(17)
Ending balance	$ 643		$ 742
As percent of ALLL	34.30%		35.10%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			742
Acquired | Commercial Portfolio Segment | Owner-occupied CRE
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 1,220		1,689
Allowance for Loan Losses (ALLL):
Beginning balance	492	604	604
Provision	(56)		(118)
Charge-offs	0		0
Recoveries	11		6
Net charge-offs	11		6
Ending balance	$ 447		$ 492
As percent of ALLL	23.90%		23.30%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			492
Acquired | Commercial Portfolio Segment | AG Production
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 0		0
Allowance for Loan Losses (ALLL):
Beginning balance	17	28	28
Provision	(4)		(11)
Charge-offs	0		0
Recoveries	0		0
Net charge-offs	0		0
Ending balance	$ 13		$ 17
As percent of ALLL	0.70%		0.80%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			17
Acquired | Commercial Real Estate Portfolio Segment | AG real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 234		248
Allowance for Loan Losses (ALLL):
Beginning balance	61	63	63
Provision	(11)		(2)
Charge-offs	0		0
Recoveries	0		0
Net charge-offs	0		0
Ending balance	$ 50		$ 61
As percent of ALLL	2.70%		2.90%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			61
Acquired | Commercial Real Estate Portfolio Segment | CRE investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 1,958		4,741
Allowance for Loan Losses (ALLL):
Beginning balance	234	231	231
Provision	5		2
Charge-offs	0		0
Recoveries	0		1
Net charge-offs	0		1
Ending balance	$ 239		$ 234
As percent of ALLL	12.70%		11.10%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			234
Acquired | Commercial Real Estate Portfolio Segment | Construction & land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 603		1,053
Allowance for Loan Losses (ALLL):
Beginning balance	98	118	118
Provision	(13)		(7)
Charge-offs	0		(13)
Recoveries	0		0
Net charge-offs	0		(13)
Ending balance	$ 85		$ 98
As percent of ALLL	4.50%		4.60%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			98
Acquired | Residential | Residential first mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 2,412		2,548
Allowance for Loan Losses (ALLL):
Beginning balance	312	412	412
Provision	(46)		(123)
Charge-offs	0		0
Recoveries	3		23
Net charge-offs	3		23
Ending balance	$ 269		$ 312
As percent of ALLL	14.30%		14.80%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			312
Acquired | Residential | Residential junior mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 57		166
Allowance for Loan Losses (ALLL):
Beginning balance	79	88	88
Provision	(12)		(9)
Charge-offs	0		0
Recoveries	2		0
Net charge-offs	2		0
Ending balance	$ 69		$ 79
As percent of ALLL	3.70%		3.70%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			79
Acquired | Residential | Residential construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 0		80
Allowance for Loan Losses (ALLL):
Beginning balance	51	$ 38	38
Provision	(16)		13
Charge-offs	0		0
Recoveries	0		0
Net charge-offs	0		0
Ending balance	$ 35		$ 51
As percent of ALLL	1.90%		2.40%
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment			$ 0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			$ 51

Loans, Allowance for Loan Los_6

Loans, Allowance for Loan Losses, and Credit Quality - Summary of changes in ALLL by portfolio segment - As percent of ALLL (Details 3) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
ALLL:
Individually evaluated	$ 0	$ 163
Collectively evaluated	12,992	12,490
Ending balance	12,992	12,653	$ 12,610	$ 11,820
Loans:
Individually evaluated	13,851	17,221
Collectively evaluated	2,129,606	2,070,704
Total loans	2,143,457	2,087,925
Less ALLL	12,992	12,653	$ 12,610	11,820
Loans, net	2,130,465	2,075,272
Retail & other
ALLL:
Individually evaluated	0	0
Collectively evaluated	306	225
Ending balance	306	225		152
Loans:
Individually evaluated	12	12
Collectively evaluated	25,440	22,803
Total loans	25,452	22,815
Less ALLL	306	225		152
Loans, net	25,146	22,590
Commercial Portfolio Segment | Commercial & industrial
ALLL:
Individually evaluated	0	163
Collectively evaluated	5,264	4,771
Ending balance	5,264	4,934		3,919
Loans:
Individually evaluated	5,858	5,870
Collectively evaluated	659,896	631,467
Total loans	665,754	637,337
Less ALLL	5,264	4,934		3,919
Loans, net	660,490	632,403
Commercial Portfolio Segment | Owner-occupied CRE
ALLL:
Individually evaluated	0	0
Collectively evaluated	2,848	2,607
Ending balance	2,848	2,607		2,867
Loans:
Individually evaluated	1,548	1,689
Collectively evaluated	447,603	428,354
Total loans	449,151	430,043
Less ALLL	2,848	2,607		2,867
Loans, net	446,303	427,436
Commercial Portfolio Segment | AG Production
ALLL:
Individually evaluated	0	0
Collectively evaluated	121	129
Ending balance	121	129		150
Loans:
Individually evaluated	0	0
Collectively evaluated	35,727	35,455
Total loans	35,727	35,455
Less ALLL	121	129		150
Loans, net	35,606	35,326
Commercial Real Estate Portfolio Segment | AG real estate
ALLL:
Individually evaluated	0	0
Collectively evaluated	294	296
Ending balance	294	296		285
Loans:
Individually evaluated	234	248
Collectively evaluated	52,144	51,530
Total loans	52,378	51,778
Less ALLL	294	296		285
Loans, net	52,084	51,482
Commercial Real Estate Portfolio Segment | CRE investment
ALLL:
Individually evaluated	0	0
Collectively evaluated	1,343	1,388
Ending balance	1,343	1,388		1,124
Loans:
Individually evaluated	2,876	5,290
Collectively evaluated	328,436	309,173
Total loans	331,312	314,463
Less ALLL	1,343	1,388		1,124
Loans, net	329,969	313,075
Commercial Real Estate Portfolio Segment | Construction & land development
ALLL:
Individually evaluated	0	0
Collectively evaluated	496	726
Ending balance	496	726		774
Loans:
Individually evaluated	603	1,053
Collectively evaluated	85,930	88,607
Total loans	86,533	89,660
Less ALLL	496	726		774
Loans, net	86,037	88,934
Residential | Residential first mortgage
ALLL:
Individually evaluated	0	0
Collectively evaluated	1,646	1,609
Ending balance	1,646	1,609		1,784
Loans:
Individually evaluated	2,663	2,801
Collectively evaluated	354,500	360,551
Total loans	357,163	363,352
Less ALLL	1,646	1,609		1,784
Loans, net	355,517	361,743
Residential | Residential junior mortgage
ALLL:
Individually evaluated	0	0
Collectively evaluated	464	488
Ending balance	464	488		461
Loans:
Individually evaluated	57	178
Collectively evaluated	109,635	105,849
Total loans	109,692	106,027
Less ALLL	464	488		461
Loans, net	109,228	105,539
Residential | Residential construction
ALLL:
Individually evaluated	0	0
Collectively evaluated	210	251
Ending balance	210	251		304
Loans:
Individually evaluated	0	80
Collectively evaluated	30,295	36,915
Total loans	30,295	36,995
Less ALLL	210	251		304
Loans, net	30,085	36,744
Originated
ALLL:
Individually evaluated		163
Collectively evaluated		10,379
Ending balance	11,118	10,542		9,449
Loans:
Individually evaluated	4,050	3,003
Collectively evaluated	1,414,877	1,240,699
Total loans	1,418,927	1,243,702
Less ALLL	11,118	10,542		9,449
Loans, net	1,407,809	1,233,160
Originated | Retail & other
ALLL:
Individually evaluated		0
Collectively evaluated		200
Ending balance	282	200		132
Loans:
Individually evaluated	0	0
Collectively evaluated	22,464	18,254
Total loans	22,464	18,254
Less ALLL	282	200		132
Loans, net	22,182	18,054
Originated | Commercial Portfolio Segment | Commercial & industrial
ALLL:
Individually evaluated		163
Collectively evaluated		4,029
Ending balance	4,621	4,192		3,150
Loans:
Individually evaluated	2,553	2,189
Collectively evaluated	548,842	486,411
Total loans	551,395	488,600
Less ALLL	4,621	4,192		3,150
Loans, net	546,774	484,408
Originated | Commercial Portfolio Segment | Owner-occupied CRE
ALLL:
Individually evaluated		0
Collectively evaluated		2,115
Ending balance	2,401	2,115		2,263
Loans:
Individually evaluated	328	0
Collectively evaluated	273,708	237,548
Total loans	274,036	237,548
Less ALLL	2,401	2,115		2,263
Loans, net	271,635	235,433
Originated | Commercial Portfolio Segment | AG Production
ALLL:
Individually evaluated		0
Collectively evaluated		112
Ending balance	108	112		122
Loans:
Individually evaluated	0	0
Collectively evaluated	10,821	11,102
Total loans	10,821	11,102
Less ALLL	108	112		122
Loans, net	10,713	10,990
Originated | Commercial Real Estate Portfolio Segment | AG real estate
ALLL:
Individually evaluated		0
Collectively evaluated		235
Ending balance	244	235		222
Loans:
Individually evaluated	0	0
Collectively evaluated	29,685	27,831
Total loans	29,685	27,831
Less ALLL	244	235		222
Loans, net	29,441	27,596
Originated | Commercial Real Estate Portfolio Segment | CRE investment
ALLL:
Individually evaluated		0
Collectively evaluated		1,154
Ending balance	1,104	1,154		893
Loans:
Individually evaluated	918	549
Collectively evaluated	150,417	113,313
Total loans	151,335	113,862
Less ALLL	1,104	1,154		893
Loans, net	150,231	112,708
Originated | Commercial Real Estate Portfolio Segment | Construction & land development
ALLL:
Individually evaluated		0
Collectively evaluated		628
Ending balance	411	628		656
Loans:
Individually evaluated	0	0
Collectively evaluated	63,106	56,061
Total loans	63,106	56,061
Less ALLL	411	628		656
Loans, net	62,695	55,433
Originated | Residential | Residential first mortgage
ALLL:
Individually evaluated		0
Collectively evaluated		1,297
Ending balance	1,377	1,297		1,372
Loans:
Individually evaluated	251	253
Collectively evaluated	211,223	190,933
Total loans	211,474	191,186
Less ALLL	1,377	1,297		1,372
Loans, net	210,097	189,889
Originated | Residential | Residential junior mortgage
ALLL:
Individually evaluated		0
Collectively evaluated		409
Ending balance	395	409		373
Loans:
Individually evaluated	0	12
Collectively evaluated	74,366	65,631
Total loans	74,366	65,643
Less ALLL	395	409		373
Loans, net	73,971	65,234
Originated | Residential | Residential construction
ALLL:
Individually evaluated		0
Collectively evaluated		200
Ending balance	175	200		266
Loans:
Individually evaluated	0	0
Collectively evaluated	30,245	33,615
Total loans	30,245	33,615
Less ALLL	175	200		266
Loans, net	30,070	33,415
Acquired
ALLL:
Individually evaluated		0
Collectively evaluated		2,111
Ending balance	1,874	2,111		2,371
Loans:
Individually evaluated	9,801	14,218
Collectively evaluated	714,729	830,005
Total loans	724,530	844,223
Less ALLL	1,874	2,111		2,371
Loans, net	722,656	842,112
Acquired | Retail & other
ALLL:
Individually evaluated		0
Collectively evaluated		25
Ending balance	24	25		20
Loans:
Individually evaluated	12	12
Collectively evaluated	2,976	4,549
Total loans	2,988	4,561
Less ALLL	24	25		20
Loans, net	2,964	4,536
Acquired | Commercial Portfolio Segment | Commercial & industrial
ALLL:
Individually evaluated		0
Collectively evaluated		742
Ending balance	643	742		769
Loans:
Individually evaluated	3,305	3,681
Collectively evaluated	111,054	145,056
Total loans	114,359	148,737
Less ALLL	643	742		769
Loans, net	113,716	147,995
Acquired | Commercial Portfolio Segment | Owner-occupied CRE
ALLL:
Individually evaluated		0
Collectively evaluated		492
Ending balance	447	492		604
Loans:
Individually evaluated	1,220	1,689
Collectively evaluated	173,895	190,806
Total loans	175,115	192,495
Less ALLL	447	492		604
Loans, net	174,668	192,003
Acquired | Commercial Portfolio Segment | AG Production
ALLL:
Individually evaluated		0
Collectively evaluated		17
Ending balance	13	17		28
Loans:
Individually evaluated	0	0
Collectively evaluated	24,906	24,353
Total loans	24,906	24,353
Less ALLL	13	17		28
Loans, net	24,893	24,336
Acquired | Commercial Real Estate Portfolio Segment | AG real estate
ALLL:
Individually evaluated		0
Collectively evaluated		61
Ending balance	50	61		63
Loans:
Individually evaluated	234	248
Collectively evaluated	22,459	23,699
Total loans	22,693	23,947
Less ALLL	50	61		63
Loans, net	22,643	23,886
Acquired | Commercial Real Estate Portfolio Segment | CRE investment
ALLL:
Individually evaluated		0
Collectively evaluated		234
Ending balance	239	234		231
Loans:
Individually evaluated	1,958	4,741
Collectively evaluated	178,019	195,860
Total loans	179,977	200,601
Less ALLL	239	234		231
Loans, net	179,738	200,367
Acquired | Commercial Real Estate Portfolio Segment | Construction & land development
ALLL:
Individually evaluated		0
Collectively evaluated		98
Ending balance	85	98		118
Loans:
Individually evaluated	603	1,053
Collectively evaluated	22,824	32,546
Total loans	23,427	33,599
Less ALLL	85	98		118
Loans, net	23,342	33,501
Acquired | Residential | Residential first mortgage
ALLL:
Individually evaluated		0
Collectively evaluated		312
Ending balance	269	312		412
Loans:
Individually evaluated	2,412	2,548
Collectively evaluated	143,277	169,618
Total loans	145,689	172,166
Less ALLL	269	312		412
Loans, net	145,420	171,854
Acquired | Residential | Residential junior mortgage
ALLL:
Individually evaluated		0
Collectively evaluated		79
Ending balance	69	79		88
Loans:
Individually evaluated	57	166
Collectively evaluated	35,269	40,218
Total loans	35,326	40,384
Less ALLL	69	79		88
Loans, net	35,257	40,305
Acquired | Residential | Residential construction
ALLL:
Individually evaluated		0
Collectively evaluated		51
Ending balance	35	51		38
Loans:
Individually evaluated	0	80
Collectively evaluated	50	3,300
Total loans	50	3,380
Less ALLL	35	51		$ 38
Loans, net	$ 15	$ 3,329

Loans, Allowance for Loan Los_7

Loans, Allowance for Loan Losses, and Credit Quality - Nonaccrual loans by portfolio segment (Details 4) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 10,182	$ 13,095
% of Total	100.00%	100.00%
Percent of total loans	0.50%	0.60%
Retail & other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 0	$ 4
% of Total	0.00%	0.00%
Commercial Portfolio Segment | Commercial & industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 5,803	$ 6,016
% of Total	57.00%	46.00%
Commercial Portfolio Segment | Owner-occupied CRE
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 474	$ 533
% of Total	4.60%	4.10%
Commercial Portfolio Segment | AG Production
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 0	$ 0
% of Total	0.00%	0.00%
Commercial Real Estate Portfolio Segment | AG real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 175	$ 186
% of Total	1.70%	1.40%
Commercial Real Estate Portfolio Segment | CRE investment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 1,381	$ 4,531
% of Total	13.60%	34.60%
Commercial Real Estate Portfolio Segment | Construction & land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 80	$ 0
% of Total	0.80%	0.00%
Residential | Residential first mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 1,973	$ 1,587
% of Total	19.40%	12.10%
Residential | Residential junior mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 268	$ 158
% of Total	2.60%	1.20%
Residential | Residential construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 28	$ 80
% of Total	0.30%	0.60%
Originated
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 4,878	$ 3,278
% of Total	100.00%	100.00%
Percent of total loans	47.90%	25.00%
Originated | Retail & other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 0	$ 4
% of Total	0.00%	0.10%
Originated | Commercial Portfolio Segment | Commercial & industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 2,729	$ 2,296
% of Total	55.90%	70.00%
Originated | Commercial Portfolio Segment | Owner-occupied CRE
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 360	$ 86
% of Total	7.40%	2.60%
Originated | Commercial Portfolio Segment | AG Production
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 0	$ 0
% of Total	0.00%	0.00%
Originated | Commercial Real Estate Portfolio Segment | AG real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 0	$ 0
% of Total	0.00%	0.00%
Originated | Commercial Real Estate Portfolio Segment | CRE investment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 918	$ 549
% of Total	18.80%	16.80%
Originated | Commercial Real Estate Portfolio Segment | Construction & land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 0	$ 0
% of Total	0.00%	0.00%
Originated | Residential | Residential first mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 777	$ 331
% of Total	15.90%	10.10%
Originated | Residential | Residential junior mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 66	$ 12
% of Total	1.40%	0.40%
Originated | Residential | Residential construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 28	$ 0
% of Total	0.60%	0.00%
Acquired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 5,304	$ 9,817
% of Total	100.00%	100.00%
Percent of total loans	52.10%	75.00%
Acquired | Retail & other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 0	$ 0
% of Total	0.00%	0.00%
Acquired | Commercial Portfolio Segment | Commercial & industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 3,074	$ 3,720
% of Total	58.00%	37.90%
Acquired | Commercial Portfolio Segment | Owner-occupied CRE
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 114	$ 447
% of Total	2.20%	4.60%
Acquired | Commercial Portfolio Segment | AG Production
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 0	$ 0
% of Total	0.00%	0.00%
Acquired | Commercial Real Estate Portfolio Segment | AG real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 175	$ 186
% of Total	3.30%	1.90%
Acquired | Commercial Real Estate Portfolio Segment | CRE investment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 463	$ 3,982
% of Total	8.70%	40.60%
Acquired | Commercial Real Estate Portfolio Segment | Construction & land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 80	$ 0
% of Total	1.50%	0.00%
Acquired | Residential | Residential first mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 1,196	$ 1,256
% of Total	22.50%	12.80%
Acquired | Residential | Residential junior mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 202	$ 146
% of Total	3.80%	1.40%
Acquired | Residential | Residential construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 0	$ 80
% of Total	0.00%	0.80%

Loans, Allowance for Loan Los_8

Loans, Allowance for Loan Losses, and Credit Quality - Summary of loans by past due status (Details 5) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	$ 2,132,151	$ 2,072,198
Total	$ 2,143,457	$ 2,087,925
As a percent of current loans	99.50%	99.30%
As a percent of total loans	100.00%	100.00%
30-89 Days Past Due (accruing)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due loans	$ 1,124	$ 2,632
Financing receivable, percent past due	0.10%	0.10%
90 Days & Over or nonaccrual
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due loans	$ 10,182	$ 13,095
Financing receivable, percent past due	0.40%	0.60%
Retail & other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	$ 25,391	$ 22,807
Total	25,452	22,815
Retail & other | 30-89 Days Past Due (accruing)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due loans	61	4
Retail & other | 90 Days & Over or nonaccrual
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due loans	0	4
Commercial Portfolio Segment | Commercial & industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	659,921	631,110
Total	665,754	637,337
Commercial Portfolio Segment | Commercial & industrial | 30-89 Days Past Due (accruing)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due loans	30	211
Commercial Portfolio Segment | Commercial & industrial | 90 Days & Over or nonaccrual
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due loans	5,803	6,016
Commercial Portfolio Segment | Owner-occupied CRE
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	448,677	428,839
Total	449,151	430,043
Commercial Portfolio Segment | Owner-occupied CRE | 30-89 Days Past Due (accruing)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due loans	0	671
Commercial Portfolio Segment | Owner-occupied CRE | 90 Days & Over or nonaccrual
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due loans	474	533
Commercial Portfolio Segment | AG Production
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	35,727	35,425
Total	35,727	35,455
Commercial Portfolio Segment | AG Production | 30-89 Days Past Due (accruing)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due loans	0	30
Commercial Portfolio Segment | AG Production | 90 Days & Over or nonaccrual
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due loans	0	0
Commercial Real Estate Portfolio Segment | AG real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	52,155	51,592
Total	52,378	51,778
Commercial Real Estate Portfolio Segment | AG real estate | 30-89 Days Past Due (accruing)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due loans	48	0
Commercial Real Estate Portfolio Segment | AG real estate | 90 Days & Over or nonaccrual
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due loans	175	186
Commercial Real Estate Portfolio Segment | CRE investment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	329,931	309,932
Total	331,312	314,463
Commercial Real Estate Portfolio Segment | CRE investment | 30-89 Days Past Due (accruing)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due loans	0	0
Commercial Real Estate Portfolio Segment | CRE investment | 90 Days & Over or nonaccrual
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due loans	1,381	4,531
Commercial Real Estate Portfolio Segment | Construction & land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	86,349	89,584
Total	86,533	89,660
Commercial Real Estate Portfolio Segment | Construction & land development | 30-89 Days Past Due (accruing)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due loans	104	76
Commercial Real Estate Portfolio Segment | Construction & land development | 90 Days & Over or nonaccrual
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due loans	80	0
Residential | Residential first mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	354,552	360,726
Total	357,163	363,352
Residential | Residential first mortgage | 30-89 Days Past Due (accruing)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due loans	638	1,039
Residential | Residential first mortgage | 90 Days & Over or nonaccrual
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due loans	1,973	1,587
Residential | Residential junior mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	109,393	105,855
Total	109,692	106,027
Residential | Residential junior mortgage | 30-89 Days Past Due (accruing)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due loans	31	14
Residential | Residential junior mortgage | 90 Days & Over or nonaccrual
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due loans	268	158
Residential | Residential construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	30,055	36,328
Total	30,295	36,995
Residential | Residential construction | 30-89 Days Past Due (accruing)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due loans	212	587
Residential | Residential construction | 90 Days & Over or nonaccrual
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due loans	$ 28	$ 80

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 6) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Total	$ 2,143,457	$ 2,087,925
As a percent of total loans	100.00%	100.00%
Grades 1- 4
Financing Receivable, Recorded Investment [Line Items]
Total	$ 2,038,635	$ 1,979,429
As a percent of total loans	95.10%	94.80%
Grade 5
Financing Receivable, Recorded Investment [Line Items]
Total	$ 68,773	$ 58,354
As a percent of total loans	3.20%	2.80%
Grade 6
Financing Receivable, Recorded Investment [Line Items]
Total	$ 11,869	$ 23,461
As a percent of total loans	0.60%	1.10%
Grade 7
Financing Receivable, Recorded Investment [Line Items]
Total	$ 24,180	$ 26,681
As a percent of total loans	1.10%	1.30%
Grade 8
Financing Receivable, Recorded Investment [Line Items]
Total	$ 0	$ 0
As a percent of total loans	0.00%	0.00%
Grade 9
Financing Receivable, Recorded Investment [Line Items]
Total	$ 0	$ 0
As a percent of total loans	0.00%	0.00%
Retail & other
Financing Receivable, Recorded Investment [Line Items]
Total	$ 25,452	$ 22,815
Retail & other | Grades 1- 4
Financing Receivable, Recorded Investment [Line Items]
Total	25,452	22,811
Retail & other | Grade 5
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Retail & other | Grade 6
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Retail & other | Grade 7
Financing Receivable, Recorded Investment [Line Items]
Total	0	4
Retail & other | Grade 8
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Retail & other | Grade 9
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Commercial Portfolio Segment | Commercial & industrial
Financing Receivable, Recorded Investment [Line Items]
Total	665,754	637,337
Commercial Portfolio Segment | Commercial & industrial | Grades 1- 4
Financing Receivable, Recorded Investment [Line Items]
Total	630,681	597,854
Commercial Portfolio Segment | Commercial & industrial | Grade 5
Financing Receivable, Recorded Investment [Line Items]
Total	20,123	12,999
Commercial Portfolio Segment | Commercial & industrial | Grade 6
Financing Receivable, Recorded Investment [Line Items]
Total	2,725	16,129
Commercial Portfolio Segment | Commercial & industrial | Grade 7
Financing Receivable, Recorded Investment [Line Items]
Total	12,225	10,355
Commercial Portfolio Segment | Commercial & industrial | Grade 8
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Commercial Portfolio Segment | Commercial & industrial | Grade 9
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Commercial Portfolio Segment | Owner-occupied CRE
Financing Receivable, Recorded Investment [Line Items]
Total	449,151	430,043
Commercial Portfolio Segment | Owner-occupied CRE | Grades 1- 4
Financing Receivable, Recorded Investment [Line Items]
Total	412,146	397,357
Commercial Portfolio Segment | Owner-occupied CRE | Grade 5
Financing Receivable, Recorded Investment [Line Items]
Total	28,643	23,340
Commercial Portfolio Segment | Owner-occupied CRE | Grade 6
Financing Receivable, Recorded Investment [Line Items]
Total	2,234	6,442
Commercial Portfolio Segment | Owner-occupied CRE | Grade 7
Financing Receivable, Recorded Investment [Line Items]
Total	6,128	2,904
Commercial Portfolio Segment | Owner-occupied CRE | Grade 8
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Commercial Portfolio Segment | Owner-occupied CRE | Grade 9
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Commercial Portfolio Segment | AG Production
Financing Receivable, Recorded Investment [Line Items]
Total	35,727	35,455
Commercial Portfolio Segment | AG Production | Grades 1- 4
Financing Receivable, Recorded Investment [Line Items]
Total	30,195	30,431
Commercial Portfolio Segment | AG Production | Grade 5
Financing Receivable, Recorded Investment [Line Items]
Total	2,892	4,000
Commercial Portfolio Segment | AG Production | Grade 6
Financing Receivable, Recorded Investment [Line Items]
Total	2,342	0
Commercial Portfolio Segment | AG Production | Grade 7
Financing Receivable, Recorded Investment [Line Items]
Total	298	1,024
Commercial Portfolio Segment | AG Production | Grade 8
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Commercial Portfolio Segment | AG Production | Grade 9
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Commercial Real Estate Portfolio Segment | AG real estate
Financing Receivable, Recorded Investment [Line Items]
Total	52,378	51,778
Commercial Real Estate Portfolio Segment | AG real estate | Grades 1- 4
Financing Receivable, Recorded Investment [Line Items]
Total	45,288	44,321
Commercial Real Estate Portfolio Segment | AG real estate | Grade 5
Financing Receivable, Recorded Investment [Line Items]
Total	3,483	4,873
Commercial Real Estate Portfolio Segment | AG real estate | Grade 6
Financing Receivable, Recorded Investment [Line Items]
Total	3,026	0
Commercial Real Estate Portfolio Segment | AG real estate | Grade 7
Financing Receivable, Recorded Investment [Line Items]
Total	581	2,584
Commercial Real Estate Portfolio Segment | AG real estate | Grade 8
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Commercial Real Estate Portfolio Segment | AG real estate | Grade 9
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Commercial Real Estate Portfolio Segment | CRE investment
Financing Receivable, Recorded Investment [Line Items]
Total	331,312	314,463
Commercial Real Estate Portfolio Segment | CRE investment | Grades 1- 4
Financing Receivable, Recorded Investment [Line Items]
Total	321,138	299,926
Commercial Real Estate Portfolio Segment | CRE investment | Grade 5
Financing Receivable, Recorded Investment [Line Items]
Total	7,086	8,399
Commercial Real Estate Portfolio Segment | CRE investment | Grade 6
Financing Receivable, Recorded Investment [Line Items]
Total	1,006	190
Commercial Real Estate Portfolio Segment | CRE investment | Grade 7
Financing Receivable, Recorded Investment [Line Items]
Total	2,082	5,948
Commercial Real Estate Portfolio Segment | CRE investment | Grade 8
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Commercial Real Estate Portfolio Segment | CRE investment | Grade 9
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Commercial Real Estate Portfolio Segment | Construction & land development
Financing Receivable, Recorded Investment [Line Items]
Total	86,533	89,660
Commercial Real Estate Portfolio Segment | Construction & land development | Grades 1- 4
Financing Receivable, Recorded Investment [Line Items]
Total	81,296	86,011
Commercial Real Estate Portfolio Segment | Construction & land development | Grade 5
Financing Receivable, Recorded Investment [Line Items]
Total	5,141	2,758
Commercial Real Estate Portfolio Segment | Construction & land development | Grade 6
Financing Receivable, Recorded Investment [Line Items]
Total	16	17
Commercial Real Estate Portfolio Segment | Construction & land development | Grade 7
Financing Receivable, Recorded Investment [Line Items]
Total	80	874
Commercial Real Estate Portfolio Segment | Construction & land development | Grade 8
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Commercial Real Estate Portfolio Segment | Construction & land development | Grade 9
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Residential | Residential first mortgage
Financing Receivable, Recorded Investment [Line Items]
Total	357,163	363,352
Residential | Residential first mortgage | Grades 1- 4
Financing Receivable, Recorded Investment [Line Items]
Total	352,778	358,067
Residential | Residential first mortgage | Grade 5
Financing Receivable, Recorded Investment [Line Items]
Total	1,388	1,868
Residential | Residential first mortgage | Grade 6
Financing Receivable, Recorded Investment [Line Items]
Total	520	683
Residential | Residential first mortgage | Grade 7
Financing Receivable, Recorded Investment [Line Items]
Total	2,477	2,734
Residential | Residential first mortgage | Grade 8
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Residential | Residential first mortgage | Grade 9
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Residential | Residential junior mortgage
Financing Receivable, Recorded Investment [Line Items]
Total	109,692	106,027
Residential | Residential junior mortgage | Grades 1- 4
Financing Receivable, Recorded Investment [Line Items]
Total	109,394	105,736
Residential | Residential junior mortgage | Grade 5
Financing Receivable, Recorded Investment [Line Items]
Total	17	117
Residential | Residential junior mortgage | Grade 6
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Residential | Residential junior mortgage | Grade 7
Financing Receivable, Recorded Investment [Line Items]
Total	281	174
Residential | Residential junior mortgage | Grade 8
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Residential | Residential junior mortgage | Grade 9
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Residential | Residential construction
Financing Receivable, Recorded Investment [Line Items]
Total	30,295	36,995
Residential | Residential construction | Grades 1- 4
Financing Receivable, Recorded Investment [Line Items]
Total	30,267	36,915
Residential | Residential construction | Grade 5
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Residential | Residential construction | Grade 6
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Residential | Residential construction | Grade 7
Financing Receivable, Recorded Investment [Line Items]
Total	28	80
Residential | Residential construction | Grade 8
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Residential | Residential construction | Grade 9
Financing Receivable, Recorded Investment [Line Items]
Total	$ 0	$ 0

Loans, Allowance for Loan Lo_10

Loans, Allowance for Loan Losses, and Credit Quality - Summary of information pertaining to impaired loans (Details 7) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Financing Receivable, Impaired [Line Items]
Recorded Investment	$ 13,851	$ 17,221
Unpaid Principal Balance	20,839	26,948
Related Allowance	0	163
Average Recorded Investment	14,640	16,810
Interest Income Recognized	1,151	1,623
Retail & other
Financing Receivable, Impaired [Line Items]
Recorded Investment	12	12
Unpaid Principal Balance	13	14
Related Allowance	0	0
Average Recorded Investment	12	12
Interest Income Recognized	1	1
Commercial Portfolio Segment | Commercial & industrial
Financing Receivable, Impaired [Line Items]
Recorded Investment	5,858	5,870
Unpaid Principal Balance	9,737	10,063
Related Allowance	0	163
Average Recorded Investment	6,389	6,586
Interest Income Recognized	534	718
Commercial Portfolio Segment | Owner-occupied CRE
Financing Receivable, Impaired [Line Items]
Recorded Investment	1,548	1,689
Unpaid Principal Balance	2,010	2,256
Related Allowance	0	0
Average Recorded Investment	1,614	1,333
Interest Income Recognized	113	132
Commercial Portfolio Segment | AG Production
Financing Receivable, Impaired [Line Items]
Recorded Investment	0	0
Unpaid Principal Balance	6	10
Related Allowance	0	0
Average Recorded Investment	0	0
Interest Income Recognized	1	0
Commercial Real Estate Portfolio Segment | AG real estate
Financing Receivable, Impaired [Line Items]
Recorded Investment	234	248
Unpaid Principal Balance	293	307
Related Allowance	0	0
Average Recorded Investment	238	233
Interest Income Recognized	14	26
Commercial Real Estate Portfolio Segment | CRE investment
Financing Receivable, Impaired [Line Items]
Recorded Investment	2,876	5,290
Unpaid Principal Balance	3,792	8,102
Related Allowance	0	0
Average Recorded Investment	2,988	5,411
Interest Income Recognized	294	465
Commercial Real Estate Portfolio Segment | Construction & land development
Financing Receivable, Impaired [Line Items]
Recorded Investment	603	1,053
Unpaid Principal Balance	1,506	1,053
Related Allowance	0	0
Average Recorded Investment	603	813
Interest Income Recognized	16	57
Residential | Residential first mortgage
Financing Receivable, Impaired [Line Items]
Recorded Investment	2,663	2,801
Unpaid Principal Balance	3,122	3,653
Related Allowance	0	0
Average Recorded Investment	2,734	2,177
Interest Income Recognized	159	180
Residential | Residential junior mortgage
Financing Receivable, Impaired [Line Items]
Recorded Investment	57	178
Unpaid Principal Balance	360	507
Related Allowance	0	0
Average Recorded Investment	62	154
Interest Income Recognized	19	17
Residential | Residential construction
Financing Receivable, Impaired [Line Items]
Recorded Investment	0	80
Unpaid Principal Balance	0	983
Related Allowance	0	0
Average Recorded Investment	0	91
Interest Income Recognized	0	27
Originated
Financing Receivable, Impaired [Line Items]
Recorded Investment	4,050	3,003
Unpaid Principal Balance	4,050	3,003
Related Allowance	0	163
Average Recorded Investment	4,453	2,964
Interest Income Recognized	213	241
Acquired
Financing Receivable, Impaired [Line Items]
Recorded Investment	9,801	14,218
Unpaid Principal Balance	16,789	23,945
Related Allowance	0	0
Average Recorded Investment	10,187	13,846
Interest Income Recognized	$ 938	$ 1,382

Loans, Allowance for Loan Lo_11

Loans, Allowance for Loan Losses, and Credit Quality - Summary of Non-accretable discount on purchase credit impaired ("PCI") loans (Details 8) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, Recorded Investment	$ 13,851		$ 17,221
Accretion Discount [Roll Forward]
Balance at beginning of period	9,471	$ 14,327	14,327
Acquired balance, net	0	8,352	8,352
Accretion to loan interest income	(1,872)	(5,925)	(7,995)
Transferred to accretable	(513)	0	(1,936)
Disposals of loans	(97)	(1,121)	(3,277)
Balance at end of period	6,989	$ 15,633	9,471
Loans And Allowance For Loan Losses, Acquired Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, Recorded Investment	$ 9,801		$ 14,218

Loans, Allowance for Loan Lo_12

Loans, Allowance for Loan Losses, and Credit Quality (Detail Textuals)	9 Months Ended	12 Months Ended
	Sep. 30, 2018USD ($)Loan	Dec. 31, 2017USD ($)Loan
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loan	5	8
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 700,000	$ 5,600,000
Financing Receivable, Modifications, Pre-Modification Recorded Investment	2,700,000	$ 6,900,000
First Menasha merger | Acquired
Loans and Leases Receivable Disclosure [Line Items]
PCI loans acquired fair value	43,600,000
Nonaccretable mark	34,400,000
Accretable mark	$ 0

Goodwill and Other Intangible_3

Goodwill and Other Intangibles and Mortgage Servicing Rights (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 107,400	$ 107,366
Other intangibles	17,994	21,040
Goodwill and other intangibles, net	125,360	128,406
Core deposit intangibles
Finite-Lived Intangible Assets [Line Items]
Other intangibles	13,488	16,477
Customer list intangibles:
Finite-Lived Intangible Assets [Line Items]
Other intangibles	$ 4,506	$ 4,563

Goodwill and Other Intangible_4

Goodwill and Other Intangibles and Mortgage Servicing Rights (Details 1) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Net book value	$ 17,994		$ 17,994		$ 21,040
Amortization during the period	1,054	$ 1,173	3,336	$ 3,514
Core deposit intangibles:
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	29,015		29,015		29,015
Accumulated amortization	(15,527)		(15,527)		(12,538)
Net book value	13,488		13,488		16,477
Additions during the period			0		3,670
Amortization during the period			2,989		4,294
Customer list intangibles:
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	5,523		5,523		5,233
Accumulated amortization	(1,017)		(1,017)		(670)
Net book value	$ 4,506		4,506		4,563
Additions during the period			290		870
Amortization during the period			$ 347		$ 401

Goodwill and Other Intangible_5

Goodwill and Other Intangibles and Mortgage Servicing Rights (Details 2) - Mortgage Servicing Rights - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Mortgage servicing rights (MSR) asset:
MSR asset at beginning of year	$ 3,187	$ 1,922
Capitalized MSR	696	876
MSR asset acquired	0	874
Amortization during the period	(464)	(485)
MSR asset at end of period	3,419	3,187
Fair value of MSR asset at end of period	4,304	4,097
Residential mortgage loans serviced for others	$ 560,607	$ 518,419
Net book value of MSR asset to loans serviced for others	0.61%	0.61%

Goodwill and Other Intangible_6

Goodwill and Other Intangibles and Mortgage Servicing Rights (Details 3) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Net book value	$ 17,994	$ 21,040
Core deposit intangibles
Finite-Lived Intangible Assets [Line Items]
2018 (remaining three months)	926
2,019	3,337
2,020	2,657
2,021	2,167
2,022	1,735
Thereafter	2,666
Net book value	13,488	16,477
Customer list intangibles:
Finite-Lived Intangible Assets [Line Items]
2018 (remaining three months)	127
2,019	507
2,020	507
2,021	507
2,022	507
Thereafter	2,351
Net book value	4,506	$ 4,563
MSR asset
Finite-Lived Intangible Assets [Line Items]
2018 (remaining three months)	161
2,019	643
2,020	814
2,021	381
2,022	381
Thereafter	1,039
Net book value	$ 3,419

Goodwill and Other Intangible_7

Goodwill and Other Intangibles and Mortgage Servicing Rights (Detail Textuals) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$ 107,400	$ 107,366

Short and Long-Term Borrowing_2

Short and Long-Term Borrowings (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2015	Dec. 31, 2017
Debt Instrument [Line Items]
Long-term borrowings	$ 77,241,000		$ 78,046,000
Tier one risk based capital	28,800,000		28,500,000
Par	38,249,000
Unamortized Discount	(8,273,000)
Carrying Value	29,976,000		29,616,000
2005 Mid-Wisconsin Financial Services, Inc.
Debt Instrument [Line Items]
Par	10,310,000
Unamortized Discount	(3,421,000)
Carrying Value	$ 6,889,000		$ 6,739,000
Debt instrument, interest rate, stated percentage	3.76%		3.02%
Base rate, description	The three-month LIBOR plus 1.43%
2006 Baylake Corp.
Debt Instrument [Line Items]
Par	$ 16,598,000
Unamortized Discount	(4,179,000)
Carrying Value	$ 12,419,000		$ 12,242,000
Debt instrument, interest rate, stated percentage	3.75%		3.04%
Base rate, description	The three-month LIBOR plus 1.35%
2004 First Menasha Bancshares, Inc.
Debt Instrument [Line Items]
Par	$ 5,155,000
Unamortized Discount	(673,000)
Carrying Value	$ 4,482,000		$ 4,449,000
Debt instrument, interest rate, stated percentage	5.12%		4.39%
Base rate, description	The three-month LIBOR plus 2.79%
2004 Nicolet Bankshares Statutory Trust
Debt Instrument [Line Items]
Par	$ 6,186,000
Unamortized Discount	0
Carrying Value	$ 6,186,000		$ 6,186,000
Debt instrument, interest rate, stated percentage	8.00%
London Interbank Offered Rate (LIBOR) | 2005 Mid-Wisconsin Financial Services, Inc.
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1.43%
London Interbank Offered Rate (LIBOR) | 2006 Baylake Corp.
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1.35%
London Interbank Offered Rate (LIBOR) | 2004 First Menasha Bancshares, Inc.
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	2.79%
FHLB advances
Debt Instrument [Line Items]
Long-term borrowings	$ 35,317,000		$ 36,509,000
Federal Home Loan Bank, advances, general debt obligations, disclosures, interest rate at period end	1.72%		1.71%
Junior subordinated debentures
Debt Instrument [Line Items]
Subordinated debt	$ 29,976,000		$ 29,616,000
Subordinated notes
Debt Instrument [Line Items]
Subordinated debt	$ 11,900,000		$ 11,921,000
Par		$ 12,000,000
Debt instrument, interest rate, stated percentage		5.00%
Subordinated notes, maturity period		10 years

Fair Value Measurements - Measu

Fair Value Measurements - Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	$ 410,911	$ 405,153
Fair Value Measurements Using Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	2,571
Fair Value Measurements Using Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	402,407	393,431
Fair Value Measurements Using Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	8,504	9,151
Recurring basis fair value measurements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	410,911	405,153
Recurring basis fair value measurements | U.S. government agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	26,254	26,209
Recurring basis fair value measurements | State, county and municipals
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	164,822	184,044
Recurring basis fair value measurements | Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	135,845	155,532
Recurring basis fair value measurements | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	83,990	36,797
Recurring basis fair value measurements | Other investments (equity securities)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments (equity securities)	2,778	2,571
Recurring basis fair value measurements | Fair Value Measurements Using Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	2,571
Recurring basis fair value measurements | Fair Value Measurements Using Level 1 | U.S. government agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Recurring basis fair value measurements | Fair Value Measurements Using Level 1 | State, county and municipals
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Recurring basis fair value measurements | Fair Value Measurements Using Level 1 | Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Recurring basis fair value measurements | Fair Value Measurements Using Level 1 | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Recurring basis fair value measurements | Fair Value Measurements Using Level 1 | Other investments (equity securities)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments (equity securities)	2,778	2,571
Recurring basis fair value measurements | Fair Value Measurements Using Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	402,407	393,431
Recurring basis fair value measurements | Fair Value Measurements Using Level 2 | U.S. government agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	26,254	26,209
Recurring basis fair value measurements | Fair Value Measurements Using Level 2 | State, county and municipals
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	164,756	183,386
Recurring basis fair value measurements | Fair Value Measurements Using Level 2 | Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	135,845	155,529
Recurring basis fair value measurements | Fair Value Measurements Using Level 2 | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	75,552	28,307
Recurring basis fair value measurements | Fair Value Measurements Using Level 2 | Other investments (equity securities)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments (equity securities)	0	0
Recurring basis fair value measurements | Fair Value Measurements Using Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	8,504	9,151
Recurring basis fair value measurements | Fair Value Measurements Using Level 3 | U.S. government agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0
Recurring basis fair value measurements | Fair Value Measurements Using Level 3 | State, county and municipals
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	66	658
Recurring basis fair value measurements | Fair Value Measurements Using Level 3 | Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	3
Recurring basis fair value measurements | Fair Value Measurements Using Level 3 | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	8,438	8,490
Recurring basis fair value measurements | Fair Value Measurements Using Level 3 | Other investments (equity securities)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments (equity securities)	$ 0	$ 0

Fair Value Measurements - Chang

Fair Value Measurements - Changes in Level 3 assets measured at fair value on a recurring basis (Details 1) - Available-for-sale Securities - Level 3 - Recurring basis fair value measurements - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Level 3 Fair Value Measurements:
Balance at beginning of year	$ 9,151	$ 9,108
Acquired balance	0	189
Paydowns/Sales/Settlements	647	146
Balance at end of period	$ 8,504	$ 9,151

Fair Value Measurements - Mea_2

Fair Value Measurements - Measured at Fair Value on Nonrecurring Basis (Details 2) - Measured at Fair Value on a Nonrecurring Basis - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	$ 13,851	$ 17,058
Other real estate owned (“OREO”)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	1,281	1,294
MSR asset
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	4,304	4,097
Fair Value Measurements Using Level 1 | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	0
Fair Value Measurements Using Level 1 | Other real estate owned (“OREO”)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	0
Fair Value Measurements Using Level 1 | MSR asset
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	0
Fair Value Measurements Using Level 2 | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	0
Fair Value Measurements Using Level 2 | Other real estate owned (“OREO”)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	0
Fair Value Measurements Using Level 2 | MSR asset
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	0
Fair Value Measurements Using Level 3 | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	13,851	17,058
Fair Value Measurements Using Level 3 | Other real estate owned (“OREO”)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	1,281	1,294
Fair Value Measurements Using Level 3 | MSR asset
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	$ 4,304	$ 4,097

Fair Value Measurements - Summa

Fair Value Measurements - Summary of carrying amounts and estimated fair values of financial instruments (Details 3) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Financial assets:
Securities AFS	$ 410,911	$ 405,153
Level 1
Financial assets:
Cash and cash equivalents	161,155	154,933
Certificates of deposit in other banks	0	0
Securities AFS	0	2,571
Other investments	2,778	0
Loans held for sale	0	0
Loans, net	0	0
BOLI	65,820	64,453
MSR asset	0	0
Financial liabilities:
Deposits	0	0
Long-term borrowings	0	0
Level 2
Financial assets:
Cash and cash equivalents	0	0
Certificates of deposit in other banks	995	1,746
Securities AFS	402,407	393,431
Other investments	13,117	13,142
Loans held for sale	2,643	4,750
Loans, net	0	0
BOLI	0	0
MSR asset	0	0
Financial liabilities:
Deposits	0	0
Long-term borrowings	35,300	36,510
Level 3
Financial assets:
Cash and cash equivalents	0	0
Certificates of deposit in other banks	0	0
Securities AFS	8,504	9,151
Other investments	1,584	1,695
Loans held for sale	0	0
Loans, net	2,103,456	2,068,382
BOLI	0	0
MSR asset	4,304	4,097
Financial liabilities:
Deposits	2,523,832	2,469,456
Long-term borrowings	40,898	40,519
Carrying Amount
Financial assets:
Cash and cash equivalents	161,155	154,933
Certificates of deposit in other banks	995	1,746
Securities AFS	410,911	405,153
Other investments	17,479	14,837
Loans held for sale	2,593	4,666
Loans, net	2,130,465	2,075,272
BOLI	65,820	64,453
MSR asset	3,419	3,187
Financial liabilities:
Deposits	2,522,156	2,471,064
Long-term borrowings	77,241	78,046
Estimated Fair Value
Financial assets:
Cash and cash equivalents	161,155	154,933
Certificates of deposit in other banks	995	1,746
Securities AFS	410,911	405,153
Other investments	17,479	14,837
Loans held for sale	2,643	4,750
Loans, net	2,103,456	2,068,382
BOLI	65,820	64,453
MSR asset	4,304	4,097
Financial liabilities:
Deposits	2,523,832	2,469,456
Long-term borrowings	$ 76,198	$ 77,029

Fair Value Measurements (Detail

Fair Value Measurements (Detail Textuals) $ in Millions	Dec. 31, 2017USD ($)
Fair Value Disclosures [Abstract]
Current fair value of equity securities reflected in other investments	$ 3.1