v3.26.1

Short and Long-Term Borrowings - Narrative (Details) - USD ($)	1 Months Ended
	Jul. 31, 2021	Mar. 31, 2026	Dec. 31, 2025
Debt Instrument [Line Items]
Short-term borrowings		$ 0	$ 0
Trust preferred securities qualify as Tier 1 capital			$ 40,000,000
Subordinated notes \| Subordinated Notes due 2031
Debt Instrument [Line Items]
Par	$ 100,000,000	$ 92,750,000
Subordinated notes \| Subordinated Notes due 2031 \| Interest Rate For The Years One Through 5
Debt Instrument [Line Items]
Fixed interest rate	3.125%
Subordinated notes \| Subordinated Notes due 2031 \| Interest Rate After Year Five
Debt Instrument [Line Items]
Floating interest rate basis spread	2.375%

It represents amount of trust preferred securities qualify as Tier 1 capital.

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NICOLET BANKSHARES INC 10-Q