Note 12 - Income Taxes (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Earliest Tax Year [Member]
Open Tax Year			2012
Permanent Differences [Member]
Unrecognized Tax Benefits, Period Increase (Decrease)	$ 143,000	$ 15,000	$ 229,000	$ 38,000
Unrecognized Tax Benefits	5,832,000		5,832,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	3,372,000		3,372,000
Deferred Tax Assets [Member]
Unrecognized Tax Benefits	7,936,000		7,936,000
Lapse of Statute of Limitations [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	2,046,000		2,046,000
Temporary Difference [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	(842,000)		(842,000)
Permanent and Temporary Differences [Member]
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	727,000		727,000
Income Tax Expense (Benefit)	$ 7,700,000	$ 7,478,000	$ 16,398,000	$ 15,894,000
Effective Income Tax Rate Reconciliation, Percent	39.40%	37.70%	39.10%	38.30%
Unrecognized Tax Benefits, Period Increase (Decrease)	$ 190,000	$ 121,000	$ 365,000	$ 330,000
Unrecognized Tax Benefits	13,768,000		13,768,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	3,599,000		3,599,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	5,831,000		5,831,000
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	$ 1,204,000		$ 1,204,000