Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Interest income:
Loans, including loan fees	$ 33,862	$ 33,778
Investment securities:
Taxable	1,814	2,072
Tax-exempt	545	491
Other interest income	655	662
Total interest income	36,876	37,003
Interest expense:
Deposits	2,922	4,957
Short-term borrowings	0	27
Long-term borrowings	313	756
Total interest expense	3,235	5,740
Net interest income	33,641	31,263
Provision for credit losses	500	3,000
Net interest income after provision for credit losses	33,141	28,263
Noninterest income:
Mortgage income, net	7,230	2,327
BOLI income	527	703
Asset gains (losses), net	711	(654)
Other income	1,072	521
Total noninterest income	17,126	9,585
Noninterest expense:
Personnel	15,116	13,323
Occupancy, equipment and office	4,137	4,204
Business development and marketing	989	1,359
Data processing	2,658	2,563
Intangibles amortization	852	993
FDIC assessments	595	0
Other expense	1,734	1,412
Total noninterest expense	26,081	23,854
Income before income tax expense	24,186	13,994
Income tax expense	5,947	3,321
Net income	18,239	10,673
Less: Net income attributable to noncontrolling interest	0	118
Net income attributable to Nicolet Bankshares, Inc.	$ 18,239	$ 10,555
Earnings per common share:
Basic (in dollars per share)	$ 1.82	$ 1.00
Diluted (in dollars per share)	$ 1.75	$ 0.98
Weighted average common shares outstanding:
Basic (in shares)	9,997,634	10,515,778
Diluted (in shares)	10,403,309	10,800,636
Trust services fee income
Noninterest income:
Fees and commissions	$ 1,775	$ 1,579
Brokerage fee income
Noninterest income:
Fees and commissions	2,793	2,322
Service charges on deposit accounts
Noninterest income:
Fees and commissions	1,091	1,225
Card interchange income
Noninterest income:
Fees and commissions	$ 1,927	$ 1,562