Note 10 - Fair Value of Financial Instruments (Details Textual) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Financial Assets at Fair Value Option	$ 13,900		$ 13,900		$ 14,300
Financial Liabilities at Fair Value Option	40,200		40,200		37,000
Fair Value, Option, Changes in Fair Value, Gain (Loss)	(170)	$ (1,297)	(537)	$ (2,834)
Financial Liabilites at Fair Value Option Contractual Principal	61,900		61,900		61,900
Financial Liabilities at Fair Value Option Accrued Interest Payable	$ 200		$ 200		200
Appraised Value of Property [Member]
Collateral Dependent Loans Measurement Input	0.85		0.85
Fair Value, Measurements, Nonrecurring [Member]
Financial and Nonfinancial Liabilities, Fair Value Disclosure	$ 0		$ 0		$ 0
Interest Rate Swaps [Member]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	$ 500	$ (400)	$ 2,900	$ (900)