Note 11 - Accumulated Other Comprehensive Loss - Summary of Reclassifications from Accumulated Other Comprehensive Loss to Net Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Amortization of defined benefit plan pension items:
After tax	$ (73)	$ (4)	$ (149)	$ 43
Amortization of gain on interest rate swap:
Reclassification to interest expense	3,154	3,468	8,812	6,854
Income tax effect	46	1,418	144	1,306
After tax	(35)	(3,442)	(262)	(5,543)
After tax	(73)	(4)	(149)	43
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Amortization of defined benefit plan pension items:
Amortization of loss	122	91	243	182
Income tax effect	(35)	(26)	(69)	(52)
After tax	87	65	174	130
Amortization of gain on interest rate swap:
After tax	87	65	174	130
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Amortization of gain on interest rate swap:
Reclassification to interest expense	(224)	(97)	(451)	(122)
Income tax effect	64	28	128	35
After tax	$ (160)	$ (69)	$ (323)	$ (87)