Note 11 - Accumulated Other Comprehensive Loss - Summary of Activity in Accumulated Other Comprehensive (Loss) Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Balance, beginning	$ 173,509	$ 169,750
Reclassifications from accumulated loss to net income	(24)	(76)
Balance, ending	168,861	170,065
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Balance, beginning	(3,070)
Other comprehensive income (loss) before reclassifications	49
Reclassifications from accumulated loss to net income	(24)
Net other comprehensive income (loss)	25
Balance, ending	(3,045)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Interest Rate Swap [Member]
Balance, beginning	(207)
Other comprehensive income (loss) before reclassifications	(2,060)
Reclassifications from accumulated loss to net income
Net other comprehensive income (loss)	(2,060)
Balance, ending	(2,267)
AOCI Attributable to Parent [Member]
Balance, beginning	(3,277)	(2,675)
Other comprehensive income (loss) before reclassifications	(2,011)
Reclassifications from accumulated loss to net income	(24)
Net other comprehensive income (loss)	(2,035)
Balance, ending	$ (5,312)	$ (2,746)