Note 13 - Income Taxes (Details) - Income Tax Reconciliation - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Reconciliation [Abstract]
Income before taxes	$ 342,489	$ 349,964	$ 257,698
(Provision) benefit for income taxes at federal statutory rate	(119,871)	(122,488)	(90,194)
(Increases) decreases in tax resulting from:
State income taxes, net of federal benefit	(11,680)	(12,961)	(9,426)
Net deferred tax asset valuation (allowance) benefit	1,405	2,030	13,115
(Increases) decreases in liability for unrecognized tax benefits	(1,611)	(1,605)	16,105
Nondeductible expenses and credits	(2,164)
Domestic production activities deduction	6,150	1,562
Other, net	(1,209)	(637)	1,417
(Provision) benefit for income taxes	$ (128,980)	$ (134,099)	$ (68,983)
Effective tax rate	37.70%	38.30%	26.80%