Note 4 - Loans Receivable - Aging of the Recorded Investment of Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Loans receivable	$ 995,887	$ 1,059,106
Loans receivable, nonaccrual	20,814	21,331
Real Estate Portfolio [Member] | One-to-Four Family Residential Real Estate [Member]
Loans receivable	17,707	18,945
Loans receivable, nonaccrual	39	37
Real Estate Portfolio [Member] | Multi-family Mortgage [Member]
Loans receivable	527,542	527,460
Real Estate Portfolio [Member] | Multi-family Mortgage [Member] | Senior Mortgage Notes [Member]
Loans receivable	488,073	485,281
Loans receivable, nonaccrual	0	0
Real Estate Portfolio [Member] | Multi-family Mortgage [Member] | Junior Mortgage Notes [Member]
Loans receivable	39,469	42,179
Loans receivable, nonaccrual	0	0
Real Estate Portfolio [Member] | Nonresidential Real Estate, Owner Occupied [Member]
Loans receivable	15,549	20,901
Loans receivable, nonaccrual	0	0
Real Estate Portfolio [Member] | Nonresidential Real Estate, Non-owner Occupied [Member]
Loans receivable	94,086	97,115
Loans receivable, nonaccrual	380	0
Commercial Loans and Leases [Member] | Commercial Loans [Member]
Loans receivable	189,977	211,981
Loans receivable, nonaccrual	1,506	2,285
Commercial Loans and Leases [Member] | Equipment Finance Leases, Government [Member]
Loans receivable	108,154	132,265
Loans receivable, nonaccrual	18,889	18,956
Commercial Loans and Leases [Member] | Equipment Finance Leases, Investment-rated [Member]
Loans receivable	41,085	49,075
Loans receivable, nonaccrual	0	53
Consumer Portfolio Segment [Member]
Loans receivable	1,787	1,364
Loans receivable, nonaccrual	0	0
Financial Asset, 30 to 59 Days Past Due [Member]
Loans receivable	3,827	3,408
Financial Asset, 30 to 59 Days Past Due [Member] | Real Estate Portfolio [Member] | One-to-Four Family Residential Real Estate [Member]
Loans receivable	13	12
Financial Asset, 30 to 59 Days Past Due [Member] | Real Estate Portfolio [Member] | Multi-family Mortgage [Member] | Senior Mortgage Notes [Member]
Loans receivable	0	0
Financial Asset, 30 to 59 Days Past Due [Member] | Real Estate Portfolio [Member] | Multi-family Mortgage [Member] | Junior Mortgage Notes [Member]
Loans receivable	0	0
Financial Asset, 30 to 59 Days Past Due [Member] | Real Estate Portfolio [Member] | Nonresidential Real Estate, Owner Occupied [Member]
Loans receivable	0	0
Financial Asset, 30 to 59 Days Past Due [Member] | Real Estate Portfolio [Member] | Nonresidential Real Estate, Non-owner Occupied [Member]
Loans receivable	0	0
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Loans and Leases [Member] | Commercial Loans [Member]
Loans receivable	1,159	234
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Loans and Leases [Member] | Equipment Finance Leases, Government [Member]
Loans receivable	2,649	3,147
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Loans and Leases [Member] | Equipment Finance Leases, Investment-rated [Member]
Loans receivable	0	7
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Loans receivable	6	8
Financial Asset, 60 to 89 Days Past Due [Member]
Loans receivable	3,533	5,077
Financial Asset, 60 to 89 Days Past Due [Member] | Real Estate Portfolio [Member] | One-to-Four Family Residential Real Estate [Member]
Loans receivable	0	18
Financial Asset, 60 to 89 Days Past Due [Member] | Real Estate Portfolio [Member] | Multi-family Mortgage [Member] | Senior Mortgage Notes [Member]
Loans receivable	107	0
Financial Asset, 60 to 89 Days Past Due [Member] | Real Estate Portfolio [Member] | Multi-family Mortgage [Member] | Junior Mortgage Notes [Member]
Loans receivable	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Real Estate Portfolio [Member] | Nonresidential Real Estate, Owner Occupied [Member]
Loans receivable	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Real Estate Portfolio [Member] | Nonresidential Real Estate, Non-owner Occupied [Member]
Loans receivable	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Loans and Leases [Member] | Commercial Loans [Member]
Loans receivable	151	26
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Loans and Leases [Member] | Equipment Finance Leases, Government [Member]
Loans receivable	3,272	5,028
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Loans and Leases [Member] | Equipment Finance Leases, Investment-rated [Member]
Loans receivable	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Loans receivable	3	5
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans receivable	0	1,007
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Real Estate Portfolio [Member] | One-to-Four Family Residential Real Estate [Member]
Loans receivable	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Real Estate Portfolio [Member] | Multi-family Mortgage [Member] | Senior Mortgage Notes [Member]
Loans receivable	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Real Estate Portfolio [Member] | Multi-family Mortgage [Member] | Junior Mortgage Notes [Member]
Loans receivable	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Real Estate Portfolio [Member] | Nonresidential Real Estate, Owner Occupied [Member]
Loans receivable	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Real Estate Portfolio [Member] | Nonresidential Real Estate, Non-owner Occupied [Member]
Loans receivable	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Loans and Leases [Member] | Commercial Loans [Member]
Loans receivable	0	666
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Loans and Leases [Member] | Equipment Finance Leases, Government [Member]
Loans receivable	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Loans and Leases [Member] | Equipment Finance Leases, Investment-rated [Member]
Loans receivable	0	341
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Loans receivable	0	0
Financial Asset, Past Due [Member]
Loans receivable	7,360	9,492
Financial Asset, Past Due [Member] | Real Estate Portfolio [Member] | One-to-Four Family Residential Real Estate [Member]
Loans receivable	13	30
Financial Asset, Past Due [Member] | Real Estate Portfolio [Member] | Multi-family Mortgage [Member] | Senior Mortgage Notes [Member]
Loans receivable	107	0
Financial Asset, Past Due [Member] | Real Estate Portfolio [Member] | Multi-family Mortgage [Member] | Junior Mortgage Notes [Member]
Loans receivable	0	0
Financial Asset, Past Due [Member] | Real Estate Portfolio [Member] | Nonresidential Real Estate, Owner Occupied [Member]
Loans receivable	0	0
Financial Asset, Past Due [Member] | Real Estate Portfolio [Member] | Nonresidential Real Estate, Non-owner Occupied [Member]
Loans receivable	0	0
Financial Asset, Past Due [Member] | Commercial Loans and Leases [Member] | Commercial Loans [Member]
Loans receivable	1,310	926
Financial Asset, Past Due [Member] | Commercial Loans and Leases [Member] | Equipment Finance Leases, Government [Member]
Loans receivable	5,921	8,175
Financial Asset, Past Due [Member] | Commercial Loans and Leases [Member] | Equipment Finance Leases, Investment-rated [Member]
Loans receivable	0	348
Financial Asset, Past Due [Member] | Consumer Portfolio Segment [Member]
Loans receivable	9	13
Financial Asset, Not Past Due [Member]
Loans receivable	967,713	1,028,283
Financial Asset, Not Past Due [Member] | Real Estate Portfolio [Member] | One-to-Four Family Residential Real Estate [Member]
Loans receivable	17,655	18,878
Financial Asset, Not Past Due [Member] | Real Estate Portfolio [Member] | Multi-family Mortgage [Member] | Senior Mortgage Notes [Member]
Loans receivable	487,966	485,281
Financial Asset, Not Past Due [Member] | Real Estate Portfolio [Member] | Multi-family Mortgage [Member] | Junior Mortgage Notes [Member]
Loans receivable	39,469	42,179
Financial Asset, Not Past Due [Member] | Real Estate Portfolio [Member] | Nonresidential Real Estate, Owner Occupied [Member]
Loans receivable	15,549	20,901
Financial Asset, Not Past Due [Member] | Real Estate Portfolio [Member] | Nonresidential Real Estate, Non-owner Occupied [Member]
Loans receivable	93,706	97,115
Financial Asset, Not Past Due [Member] | Commercial Loans and Leases [Member] | Commercial Loans [Member]
Loans receivable	187,161	208,770
Financial Asset, Not Past Due [Member] | Commercial Loans and Leases [Member] | Equipment Finance Leases, Government [Member]
Loans receivable	83,344	105,134
Financial Asset, Not Past Due [Member] | Commercial Loans and Leases [Member] | Equipment Finance Leases, Investment-rated [Member]
Loans receivable	41,085	48,674
Financial Asset, Not Past Due [Member] | Consumer Portfolio Segment [Member]
Loans receivable	$ 1,778	$ 1,351