Note 10 - Leases - Balance Sheet Information (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Operating leases:
Operating lease right of use assets	$ 80,458
Operating lease liabilities - current	2,517
Operating lease liabilities - noncurrent	77,937
Total liabilities	80,454
Finance leases:
Finance leases, liability, current	46
Finance leases, liability, noncurrent	2,705
Total finance lease liabilities	2,751
Property, Plant and Equipment [Member]
Finance leases:
Finance leases, assets	2,519
Accumulated Depreciation and Amortization [Member]
Finance leases:
Finance leases, assets, depreciation and amortization	(1,410)
Property, Plant and Equipment, Net [Member]
Finance leases:
Finance leases, assets	1,109
Current Portion of Long-term Obligations [Member]
Finance leases:
Finance leases, liability, current	46
Long-term Obligations, Net of Current Portion [Member]
Finance leases:
Finance leases, liability, noncurrent	$ 2,705