Note 5 - Mortgage Loan Servicing - Activity for Capitalized Mortgage Loan Servicing Rights (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Balance at beginning of year	$ 4,652,000	$ 4,436,000
Additions	6,467,000	1,962,000
Amortized to expense	(2,930,000)	(1,746,000)
Balance at end of year	$ 8,189,000	$ 4,652,000