Note 10 - Income Taxes Effect of Unrecognized Tax Benefits on Consolidated Balance Sheets and Results of Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2018
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 112,300
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	65,700
Unrecognized Tax Benefits, Interest and Penalties Charged to Income	2,200	$ 1,800	$ 800
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of period	123,028	124,246
Tax positions related to the current year [Abstract]
Unrecognized Tax Benefits, Increases Resulting from Current Period Tax Positions	2,343	1,203
Unrecognized Tax Benefits, Decrease Resulting from Current Period Tax Positions	0	1,835
Tax positions related to prior years [Abstract]
Unrecognized Tax Benefits, Increases Resulting from Prior Period Tax Positions	24,122	22,389
Unrecognized Tax Benefits, Decreases Resulting from Prior Period Tax Positions	(1,437)	(1,406)
Unrecognized Tax Benefits, Reductions Resulting from Lapse of Applicable Statute of Limitations	(24,105)	(21,569)
Balance at end of period	123,951	$ 123,028	$ 124,246
Unrecognized Tax Benefits, Net Amount Related to Prior Period Tax Positions	22,700
Recognition of Insurance Premium Income [Member]
Tax positions related to prior years [Abstract]
Unrecognized Tax Benefits, Reductions Resulting from Lapse of Applicable Statute of Limitations	$ (24,100)
Scenario, Forecast [Member]
Tax positions related to prior years [Abstract]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit				$ 70,000