Note 10 - Fair Value of Financial Instruments - Financial Assets and Liabilities Reported Under the Fair Value Option (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Financial Assets at Fair Value Option		$ 13,900		$ 13,900		$ 14,300
Net loss from fair value adjustments		(170)	$ (1,297)	(537)	$ (2,834)
Collateralized Mortgage Backed Securities [Member]
Financial Assets at Fair Value Option		1,330		1,330		1,590
Net loss from fair value adjustments		(6)	(5)	(17)	(15)
Other Securities [Member]
Financial Assets at Fair Value Option		12,610		12,610		12,685
Net loss from fair value adjustments		(72)	40	(272)	184
Junior Subordinated Debentures [Member]
Financial Assets at Fair Value Option		40,151		40,151		$ 36,986
Net loss from fair value adjustments		(607)	(925)	(3,155)	(2,090)
Financial Assets and Liabilities, Excluding Interest Rate Caps / Swaps [Member]
Net loss from fair value adjustments	[1],[2]	$ (685)	$ (890)	$ (3,444)	$ (1,921)

[1] The net loss from fair value adjustments presented in the above table does not include net gains (losses) of $0.5 million and ($0.4) million for the three months ended September 30, 2018 and 2017, respectively, from the change in the fair value of interest rate swaps.

[2] The net loss from fair value adjustments presented in the above table does not include net gains (losses) of $2.9 million and ($0.9) million for the nine months ended September 30, 2018 and 2017, respectively, from the change in the fair value of interest rate swaps.