Note 8 - Leases - Lease Obligations (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Amortization of right-of-use assets	$ 1,411
Interest on lease liabilities	227
Operating lease cost	6,182
Variable lease cost
Total lease cost	7,820
Operating cash flows from finance leases	1,146
Operating cash flows from operating leases	6,182
Financing cash flows from finance leases	227
Right-of-use assets obtained in exchange for new finance lease liabilities
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 4,146
Weighted-average remaining lease term—finance leases (Year)	3 years 182 days
Weighted-average remaining lease term—operating leases (Year)	3 years 219 days
Weighted-average discount rate—finance leases	3.00%
Weighted-average discount rate—operating leases	4.20%