NSTS Bancorp, Inc. Quarterly report [Sections 13 or 15(d)]

Note 3 - Loans and Allowance for Credit Losses - Aging of Bank's Loan Portfolio (Details)

Note 3 - Loans and Allowance for Credit Losses - Aging of Bank's Loan Portfolio (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024	Jan. 01, 2024
Loans	$ 133,835	$ 130,907
Non-Accrual	285	0	$ 200
First Mortgage Loans [Member]
Loans	133,551	130,625
First Mortgage Loans [Member] \| One To Four Family Residential [Member]
Loans	121,443	119,409
Non-Accrual	285	0	200
First Mortgage Loans [Member] \| Multifamily [Member]
Loans	3,272	3,368
Non-Accrual	0	0	0
First Mortgage Loans [Member] \| Commercial Real Estate [Member]
Loans	4,318	4,197
Non-Accrual	0	0	0
First Mortgage Loans [Member] \| Construction Loans [Member]
Loans	4,518	3,651
Non-Accrual	0	0	0
Consumer Portfolio Segment [Member]
Loans	284	282
Non-Accrual	0	0	$ 0
Financial Asset, 31 to 89 Days Past Due [Member]
Loans	179	371
Financial Asset, 31 to 89 Days Past Due [Member] \| First Mortgage Loans [Member] \| One To Four Family Residential [Member]
Loans	179	371
Financial Asset, 31 to 89 Days Past Due [Member] \| First Mortgage Loans [Member] \| Multifamily [Member]
Loans	0	0
Financial Asset, 31 to 89 Days Past Due [Member] \| First Mortgage Loans [Member] \| Commercial Real Estate [Member]
Loans	0	0
Financial Asset, 31 to 89 Days Past Due [Member] \| First Mortgage Loans [Member] \| Construction Loans [Member]
Loans	0	0
Financial Asset, 31 to 89 Days Past Due [Member] \| Consumer Portfolio Segment [Member]
Loans	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] \| First Mortgage Loans [Member] \| One To Four Family Residential [Member]
Loans	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] \| First Mortgage Loans [Member] \| Multifamily [Member]
Loans	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] \| First Mortgage Loans [Member] \| Commercial Real Estate [Member]
Loans	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] \| First Mortgage Loans [Member] \| Construction Loans [Member]
Loans	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] \| Consumer Portfolio Segment [Member]
Loans	0	0
Financial Asset, Past Due [Member]
Loans	464	371
Financial Asset, Past Due [Member] \| First Mortgage Loans [Member] \| One To Four Family Residential [Member]
Loans	464	371
Financial Asset, Past Due [Member] \| First Mortgage Loans [Member] \| Multifamily [Member]
Loans	0	0
Financial Asset, Past Due [Member] \| First Mortgage Loans [Member] \| Commercial Real Estate [Member]
Loans	0	0
Financial Asset, Past Due [Member] \| First Mortgage Loans [Member] \| Construction Loans [Member]
Loans	0	0
Financial Asset, Past Due [Member] \| Consumer Portfolio Segment [Member]
Loans	0	0
Financial Asset, Not Past Due [Member]
Loans	133,371	130,536
Financial Asset, Not Past Due [Member] \| First Mortgage Loans [Member] \| One To Four Family Residential [Member]
Loans	120,979	119,038
Financial Asset, Not Past Due [Member] \| First Mortgage Loans [Member] \| Multifamily [Member]
Loans	3,272	3,368
Financial Asset, Not Past Due [Member] \| First Mortgage Loans [Member] \| Commercial Real Estate [Member]
Loans	4,318	4,197
Financial Asset, Not Past Due [Member] \| First Mortgage Loans [Member] \| Construction Loans [Member]
Loans	4,518	3,651
Financial Asset, Not Past Due [Member] \| Consumer Portfolio Segment [Member]
Loans	$ 284	$ 282