Note 3 - Loans Receivable - Troubled Debt Restructurings (Details) - USD ($) $ in Thousands	Jun. 30, 2023		Dec. 31, 2022		Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
Total TDR loans			$ 1,753
Allowance for credit losses on loans related to TDR loans	$ 17,297	[1]	16,116	[1]	$ 15,747	$ 15,127	$ 15,124
Total nonaccrual TDR loans			29
Total accrual TDR loans			1,724
Troubled Debt Restructurings [Member]
Allowance for credit losses on loans related to TDR loans			21
One-to-four Family Loan [Member] | Real Estate Portfolio Segment [Member]
Total TDR loans			1,726
Allowance for credit losses on loans related to TDR loans	3,012		3,343		3,026	3,039	3,184
Total nonaccrual TDR loans			29
Total accrual TDR loans			1,697
Home Equity Loan [Member] | Consumer Portfolio Segment [Member]
Total TDR loans			27
Allowance for credit losses on loans related to TDR loans	$ 1,125		549		$ 486	$ 405	$ 407
Total nonaccrual TDR loans			0
Total accrual TDR loans			$ 27

[1] Allowance for credit losses on loans in 2023 reported using the CECL method and in 2022 reported using the incurred loss method.