PARENT COMPANY ONLY FINANCIAL INFORMATION - Statements of Income (Details 1) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Condensed Financial Statements, Captions [Line Items]      
Interest income $ 75,467 $ 48,597 $ 48,949
Interest expense 7,334 7,213 7,067
Net interest expense (68,133) (41,384) (41,882)
Income tax benefit 9,371 6,089 4,607
Net income 18,694 11,555 10,051
Nicolet Bankshares, Inc      
Condensed Financial Statements, Captions [Line Items]      
Interest income 58 90 68
Interest expense 1,951 1,375 875
Net interest expense (1,893) (1,285) (807)
Dividend income from subsidiaries 35,500 11,000 9,060
Operating expense (202) (258) (164)
Gain (loss) on investments, net (500) 228 341
Bargain purchase gain
Income tax benefit 833 375 135
Earnings before equity in undistributed income of subsidiaries 33,738 10,060 8,565
Equity in undistributed income (loss) of subsidiaries (15,276) 1,368 1,384
Net income $ 18,462 $ 11,428 $ 9,949