Note 9 - Fair Value of Financial Instruments (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Financial Assets at Fair Value Option	$ 21,400		$ 21,400		$ 30,400
Financial Liabilities at Fair Value Option	36,100		36,100		34,000
Fair Value, Option, Changes in Fair Value, Gain (Loss)	(1,297)	$ (823)	(2,834)	$ (2,925)
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		100
Fair Value, Assets, Level 2 to Level 1 Transfers, Amount	11,600		$ 11,600
Fair Value Inputs, Discount Rate			85.00%
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets, Fair Value Disclosure	0		$ 0		0
Financial and Nonfinancial Liabilities, Fair Value Disclosure	0		0		0
Fair Value, Measurements, Nonrecurring [Member]
Financial and Nonfinancial Liabilities, Fair Value Disclosure	0		0		$ 0
Interest Rate Swap [Member]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	$ (400)	$ (500)	$ (900)	$ (4,300)