Basis of Presentation	6 Months Ended
Basis of Presentation	Jun. 30, 2022
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 (loss), changes in stockholders’ equity and cash flows of Nicolet Bankshares, Inc. (the “Company” or “Nicolet”) and its subsidiaries, as of and 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, 2021. 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 credit losses, valuation of loans in acquisition transactions, useful lives for depreciation and amortization, fair value of financial instruments, 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 credit 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, 2021. Future Accounting Pronouncements In March 2022, the FASB issued ASU 2022-02, Financial Instruments - Credit Losses (Topic 326): Troubled Debt Restructurings (“TDRs”) and Vintage Disclosures. This ASU eliminates the accounting guidance for TDRs by creditors, while enhancing the disclosure requirements for certain loan refinancings and restructurings by creditors when a borrower is experiencing financial difficulty. The ASU also requires public business entities to expand the vintage disclosures to include gross charge-offs by year of origination. The updated guidance is effective for fiscal years beginning after December 15, 2022, with early adoption permitted. Adoption of this amendment is not expected to have a material impact on the Company’s consolidated financial statements; though, it will result in new disclosures of gross charge-offs by year of origination and on the types of loan modifications to borrowers experiencing financial difficulties. Current TDR disclosures will be also removed. In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting. This ASU provides optional guidance for a limited period of time to ease the potential burden in accounting for (or recognizing the effects of) reference rate reform on financial reporting. It provides optional expedients and exceptions for applying GAAP to contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. The updated guidance is effective for all entities as of March 12, 2020 through December 31, 2022. The Company continues to work through the cessation of LIBOR, including the modification of its loans and other financial instruments with attributes that are either directly or indirectly influenced by LIBOR. The Company expects to utilize the reference rate reform transition guidance, as applicable, and does not expect such adoption to have a material impact on its consolidated financial statements or financial disclosures. The Company will continue to assess the impact as the reference rate transition approaches June 30, 2023. Reclassifications Certain amounts in the 2021 consolidated financial statements have been reclassified to conform to the 2022 presentation. These reclassifications were not material and did not impact previously reported net income or comprehensive income.