Note 6 - Long-term Leases - Future Minimum Lease Payments (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
2018, operating leases	$ 34,200
2018, capital leases	5,200
2019, operating leases	34,200
2019, capital leases	5,200
2020, operating leases	34,200
2020, capital leases	5,200
2021, operating leases	34,200
2021, capital leases	5,200
2022, operating leases	34,200
2022, capital leases	5,200
Thereafter, operating leases	159,650
Thereafter, capital leases	8,667
Total minimum lease payments, operating leases	330,650
Total minimum lease payments, capital leases	34,667
Less: Amounts representing interest, capital leases	(6,153)
Present value of minimum lease payments, capital leases	28,514
Less: Current portion, capital leases	(3,587)	$ (3,481)
Long-term capital lease obligations, capital leases	$ 24,927	$ 26,748