REGULATORY CAPITAL REQUIREMENTS AND RESTRICTIONS OF DIVIDENDS - The Company's and the Bank's actual regulatory capital amounts and ratios (Details) - USD ($)
$ in Thousands
Dec. 31, 2016
Dec. 31, 2015
Nicolet Bankshares, Inc    
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]    
Total risk-based capital, Actual amount $ 249,723 $ 140,691
Total risk-based capital, For capital adequacy purposes amount $ 144,195 $ 75,972
Total risk-based capital, Actual ratio [1] 13.90% 14.80%
Total risk-based capital, For capital adequacy purposes ratio [1] 8.00% 8.00%
Tier I risk-based capital, Actual amount $ 226,018 $ 118,535
Tier I risk-based capital, For capital adequacy purposes amount $ 108,146 $ 56,979
Tier I risk-based capital, Actual ratio [1] 12.50% 12.50%
Tier I risk-based capital, For capital adequacy purposes ratio [1] 6.00% 6.00%
Common equity Tier 1 capital $ 202,313 $ 94,346
Common equity Tier 1 capital, For Capital Adequacy Purposes $ 81,110 $ 42,697
Common equity Tier 1 capital, Actual ratio [1] 11.20% 9.90%
Common equity Tier 1 capital, For capital adequacy purposes ratio [1] 4.50% 4.50%
Leverage, Actual amount $ 226,018 $ 118,535
Leverage, For capital adequacy purposes amount $ 87,566 $ 47,627
Leverage, Actual ratio [1] 10.30% 10.00%
Leverage, For capital adequacy purposes ratio [1] 4.00% 4.00%
Nicolet national bank    
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]    
Total risk-based capital, Actual amount $ 217,682 $ 122,206
Total risk-based capital, For capital adequacy purposes amount 144,322 74,903
Total risk-based capital, To be well capitalized under prompt corrective action provisions amount [2] $ 180,403 $ 93,629
Total risk-based capital, Actual ratio [1] 12.10% 13.10%
Total risk-based capital, For capital adequacy purposes ratio [1] 8.00% 8.00%
Total risk-based capital, To be well capitalized under prompt corrective action provisions ratio [1],[2] 10.00% 10.00%
Tier I risk-based capital, Actual amount $ 205,862 $ 111,899
Tier I risk-based capital, For capital adequacy purposes amount 108,242 56,178
Tier I risk-based capital, To be well capitalized under prompt corrective action provisions amount [2] $ 144,322 $ 74,903
Tier I risk-based capital, Actual ratio [1] 11.40% 12.00%
Tier I risk-based capital, For capital adequacy purposes ratio [1] 6.00% 6.00%
Tier I risk-based capital, To be well capitalized under prompt corrective action provisions ratio [1],[2] 8.00% 8.00%
Common equity Tier 1 capital $ 205,862 $ 111,899
Common equity Tier 1 capital, For Capital Adequacy Purposes 81,181 42,133
Common equity Tier 1 capital, To Be Well Capitalized Under Prompt Corrective Action Provisions [2] $ 117,262 $ 60,859
Common equity Tier 1 capital, Actual ratio [1] 11.40% 12.00%
Common equity Tier 1 capital, For capital adequacy purposes ratio [1] 4.50% 4.50%
Common equity Tier 1 capital, To be well capitalized under prompt corrective action provisions ratio [1],[2] 6.50% 6.50%
Leverage, Actual amount $ 205,862 $ 111,899
Leverage, For capital adequacy purposes amount 87,329 47,036
Leverage, To be well capitalized under prompt corrective action provisions amount [2] $ 109,161 $ 58,794
Leverage, Actual ratio [1] 9.40% 9.50%
Leverage, For capital adequacy purposes ratio [1] 4.00% 4.00%
Leverage, To be well capitalized under prompt corrective action provisions ratio [1],[2] 5.00% 5.00%
[1] The Total risk-based capital ratio is defined as Tier 1 capital plus tier 2 capital divided by total risk-weighted assets. The Tier 1 risk-based capital ratio is defined as Tier 1 capital divided by total risk-weighted assets. CET1 risk-based capital ratio is defined as Tier 1 capital, with deductions for goodwill and other intangible assets (other than mortgage servicing assets), net of associated deferred tax liabilities, and limitations on the inclusion of deferred tax assets, mortgage servicing assets and investments in other financial institutions, in each case as provided further in the rules, divided by total risk-weighted assets. The Leverage ratio is defined as Tier 1 capital divided by the most recent quarter's average total assets as adjusted.
[2] Prompt corrective action provisions are not applicable at the bank holding company level.