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	Mar. 31, 2026	Dec. 31, 2025	Jan. 01, 2025
Loans	$ 128,485	$ 129,464
Non-Accrual	283	284	$ 0
First Mortgage Loans [Member]
Loans	128,163	129,196
First Mortgage Loans [Member] \| One To Four Family Residential [Member]
Loans	116,914	118,222
Non-Accrual	283	284	0
First Mortgage Loans [Member] \| Multifamily [Member]
Loans	3,425	3,240
Non-Accrual	0	0	0
First Mortgage Loans [Member] \| Commercial Real Estate [Member]
Loans	3,797	3,813
Non-Accrual	0	0	0
First Mortgage Loans [Member] \| Construction Loans [Member]
Loans	4,027	3,921
Non-Accrual	0	0	0
Consumer Portfolio Segment [Member]
Loans	322	268
Non-Accrual	0	0	$ 0
Financial Asset, 31 to 89 Days Past Due [Member]
Loans	1,530	641
Financial Asset, 31 to 89 Days Past Due [Member] \| First Mortgage Loans [Member] \| One To Four Family Residential [Member]
Loans	1,530	641
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	1,813	925
Financial Asset, Past Due [Member] \| First Mortgage Loans [Member] \| One To Four Family Residential [Member]
Loans	1,813	925
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	126,672	128,539
Financial Asset, Not Past Due [Member] \| First Mortgage Loans [Member] \| One To Four Family Residential [Member]
Loans	115,101	117,297
Financial Asset, Not Past Due [Member] \| First Mortgage Loans [Member] \| Multifamily [Member]
Loans	3,425	3,240
Financial Asset, Not Past Due [Member] \| First Mortgage Loans [Member] \| Commercial Real Estate [Member]
Loans	3,797	3,813
Financial Asset, Not Past Due [Member] \| First Mortgage Loans [Member] \| Construction Loans [Member]
Loans	4,027	3,921
Financial Asset, Not Past Due [Member] \| Consumer Portfolio Segment [Member]
Loans	$ 322	$ 268