Note 10 - Fair Value of Financial Instruments - Financial Assets and Liabilities Reported Under the Fair Value Option (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Financial Assets at Fair Value Option		$ 14,000		$ 14,000		$ 14,300
Net loss from fair value adjustments		(267)	$ (1,159)	(367)	$ (1,537)
Collateralized Mortgage Backed Securities [Member]
Financial Assets at Fair Value Option		1,426		1,426		1,590
Net loss from fair value adjustments			(3)	(11)	(10)
Other Securities [Member]
Financial Assets at Fair Value Option		12,615		12,615		12,685
Net loss from fair value adjustments		(62)	112	(200)	144
Junior Subordinated Debentures [Member]
Financial Assets at Fair Value Option		39,566		39,566		$ 36,986
Net loss from fair value adjustments		(867)	(595)	(2,548)	(1,165)
Financial Assets and Liabilities, Excluding Interest Rate Caps / Swaps [Member]
Net loss from fair value adjustments	[1]	$ (929)	$ (486)	$ (2,759)	$ (1,031)

[1] The net loss from fair value adjustments presented in the above table does not include net gains of $1.7 million and $0.2 million for the three months ended March 31, 2018 and 2017, respectively, from the change in the fair value of interest rate swaps.