Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Interest income:
Loans, including loan fees	$ 34,047	$ 31,334	$ 101,591	$ 92,511
Investment securities:
Taxable	2,001	1,904	6,115	5,578
Tax-exempt	542	503	1,542	1,574
Other interest income	680	926	1,917	2,733
Total interest income	37,270	34,667	111,165	102,396
Interest expense:
Deposits	3,784	4,596	13,196	14,103
Short-term borrowings	0	0	65	0
Long-term borrowings	926	881	2,584	2,684
Total interest expense	4,710	5,477	15,845	16,787
Net interest income	32,560	29,190	95,320	85,609
Provision for credit losses	3,000	400	9,000	900
Net interest income after provision for credit losses	29,560	28,790	86,320	84,709
Noninterest income:
Mortgage income, net	9,675	3,700	21,965	6,962
BOLI income	531	495	1,774	1,834
Asset gains (losses), net	217	286	(1,185)	8,030
Other income	1,237	1,166	3,245	4,274
Total noninterest income	18,691	12,312	45,747	40,058
Noninterest expense:
Personnel	14,072	12,914	41,877	40,809
Occupancy, equipment and office	4,051	3,454	12,616	10,961
Business development and marketing	810	1,428	4,683	4,288
Data processing	2,658	2,515	7,620	7,220
Intangibles amortization	834	914	2,707	2,936
Other expense	1,260	1,662	5,849	5,159
Total noninterest expense	23,685	22,887	75,352	71,373
Income before income tax expense	24,566	18,215	56,715	53,394
Income tax expense	6,434	4,603	14,331	10,788
Net income	18,132	13,612	42,384	42,606
Less: Net income attributable to noncontrolling interest	30	82	249	260
Net income attributable to Nicolet Bankshares, Inc.	$ 18,102	$ 13,530	$ 42,135	$ 42,346
Earnings per common share:
Basic (in dollars per share)	$ 1.75	$ 1.45	$ 4.04	$ 4.51
Diluted (in dollars per share)	$ 1.72	$ 1.40	$ 3.97	$ 4.36
Weighted average common shares outstanding:
Basic (in shares)	10,348,862	9,346,814	10,426,228	9,393,795
Diluted (in shares)	10,498,552	9,696,850	10,604,732	9,706,795
Trust services fee income
Noninterest income:
Fees and commissions	$ 1,628	$ 1,594	$ 4,717	$ 4,631
Brokerage fee income
Noninterest income:
Fees and commissions	2,489	2,113	7,080	5,925
Service charges on deposit accounts
Noninterest income:
Fees and commissions	1,037	1,223	3,075	3,587
Card interchange income
Noninterest income:
Fees and commissions	$ 1,877	$ 1,735	$ 5,076	$ 4,815