RELATED PARTY TRANSACTIONS (Detail Textuals) - USD ($)
1 Months Ended 12 Months Ended
Feb. 29, 2016
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2004
Related Party Transaction [Line Items]          
Related party loans, total   $ 54,000,000 $ 25,400,000    
Rent expense $ 120,000        
Building lease expense for partial year   120,000      
Payment for services   420,000      
New branch location in facility opened in August 2011 | Maximum          
Related Party Transaction [Line Items]          
Rent expense   120,000 120,000 $ 120,000  
New branch location in facility opened in October 2013 | Maximum          
Related Party Transaction [Line Items]          
Rent expense   120,000 120,000 120,000  
Nicolet Joint Ventures, LLC (the "JV")          
Related Party Transaction [Line Items]          
Percentage of Nicolet National Bank         50.00%
Relative of the management          
Related Party Transaction [Line Items]          
Payment for services   $ 400,000      
Nicolet national bank          
Related Party Transaction [Line Items]          
Percentage of Nicolet National Bank   100.00%      
Nicolet national bank | Nicolet Joint Ventures, LLC (the "JV")          
Related Party Transaction [Line Items]          
Rent expense   $ 1,100,000 $ 1,200,000 $ 1,200,000