Note 10 - Income Taxes (Details Textual)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			35.00%	35.00%
Effective Income Tax Rate Reconciliation, Percent	40.70%	136.50%	40.60%	42.00%
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent			4.30%	4.60%
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Percent			1.30%	2.10%
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Compensation Cost, Percent				1.00%
Effective Income Tax Rate Reconciliation, Tax Contingency, State and Local, Percent				0.70%