Note 10 - Leases - Balance Sheet Information (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Operating lease right of use assets	$ 80,394	$ 80,991
Operating lease liabilities - current	2,902	2,795
Operating lease liabilities - noncurrent	78,207	78,767
Total liabilities	81,109	81,562
Finance leases, liability, current	56
Finance leases, liability, noncurrent	2,661
Total finance lease liabilities	2,717	2,729
Property, Plant and Equipment [Member]
Finance leases, assets	5,800	5,800
Accumulated Depreciation and Amortization [Member]
Finance leases, assets, depreciation and amortization	(3,746)	(3,699)
Property, Plant and Equipment, Net [Member]
Finance leases, assets	2,054	2,101
Current Portion of Long-term Obligations [Member]
Finance leases, liability, current	56	53
Long-term Obligations, Net of Current Portion [Member]
Finance leases, liability, noncurrent	$ 2,661	$ 2,676