Note 5 - Income Taxes (Details) - Components of Provision for Income Taxes (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current:
Federal	$ 10,402us-gaap_CurrentFederalTaxExpenseBenefit	$ 15,964us-gaap_CurrentFederalTaxExpenseBenefit	$ 12,728us-gaap_CurrentFederalTaxExpenseBenefit
State	2,015	1,889	587
	12,417us-gaap_CurrentIncomeTaxExpenseBenefit	17,853us-gaap_CurrentIncomeTaxExpenseBenefit	13,315us-gaap_CurrentIncomeTaxExpenseBenefit
Deferred:
Federal	8,648	3,909	5,542
State	774	394	(720)
	9,422us-gaap_DeferredIncomeTaxExpenseBenefit	4,303us-gaap_DeferredIncomeTaxExpenseBenefit	4,822us-gaap_DeferredIncomeTaxExpenseBenefit
Total provision	$ 21,839us-gaap_IncomeTaxExpenseBenefit	$ 22,156us-gaap_IncomeTaxExpenseBenefit	$ 18,137us-gaap_IncomeTaxExpenseBenefit

Amount of current federal tax expense (benefit) pertaining to income (loss) from continuing operations.

Amount of current income tax expense (benefit) pertaining to taxable income (loss) from continuing operations.

Amount of current state and local tax expense (benefit) pertaining to income (loss) from continuing operations.

Amount of deferred federal income tax expense (benefit) pertaining to income (loss) from continuing operations.

Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations.

Amount of deferred state and local tax expense (benefit) pertaining to income (loss) from continuing operations.