Note 10 - Intangible Assets - Risk Characteristics of Loans Being Serviced (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Original Term Thirty Year Fixed Rate [Member]
Loan Principal Balance	$ 272,082
Weighted Average Interest Rate	4.07%
Weighted Average Remaining Term (Month)	25 years 150 days
Number of Loans	2,143
Original Term Fifteen Year Fixed Rate [Member]
Loan Principal Balance	$ 101,530
Weighted Average Interest Rate	3.11%
Weighted Average Remaining Term (Month)	11 years 60 days
Number of Loans	1,057
Adjustable Rate [Member]
Loan Principal Balance	$ 55
Weighted Average Interest Rate	3.25%
Weighted Average Remaining Term (Month)	23 years 60 days
Number of Loans	2