Note 8 - Income Taxes - Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Federal net operating loss carryforwards	$ 95,861	$ 102,806
State net operating loss carryforwards	67,357	55,478
Operating lease liability	198,800	0
Share-based compensation	15,029	15,127
Other	60,540	53,434
Gross deferred income tax assets	437,587	226,845
Valuation allowance	(41,281)	(39,516)
Deferred income tax assets, net of valuation allowance	396,306	187,329
Difference between book and tax basis of property and intangible assets	311,365	259,495
State tax liability	45,314	38,891
Right of use asset	194,874	0
Other	7,448	10,205
Gross deferred income tax liabilities	559,001	308,591
Deferred income tax liabilities, net	$ 162,695	$ 121,262