Note 21 - Commitments - (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Leases, Rent Expense, Total	$ 2,500,000	$ 1,800,000	$ 1,500,000
Federal Home Loan Bank Advances [Member]
Letters of Credit Outstanding, Amount	137,300,000	$ 81,000,000
Letters of Credit of Expiring in April 2019 [Member]
Letters of Credit Outstanding, Amount	25,000,000
Letters of Credit of Expiring in May 2019 [Member]
Letters of Credit Outstanding, Amount	16,900,000
Letter of Credit of Expires in August 2019 [Member]
Letters of Credit Outstanding, Amount	157,000
Letter of Credit of Expires in September 2019 [Member]
Letters of Credit Outstanding, Amount	35,000,000
Letters of Credit of Expiring in December 2019 [Member]
Letters of Credit Outstanding, Amount	$ 60,300,000
Minimum [Member]
Non-cancelable Operating Lease Terms	1 year
Maximum [Member]
Non-cancelable Operating Lease Terms	10 years