Note 10 - Stock Based Compensation (Tables)

3 Months Ended

Mar. 31, 2017

Notes Tables

Share-based Compensation, Stock Options, Activity [Table Text Block]

Options	Number of Shares			Weighted Average Exercise Price
Outstanding at December 31, 2016		1,519,338		$	25.22
Granted		39,037			54.15
Exercised		(61,249	)		11.83
Outstanding at March 31, 2017		1,497,126			26.52
Exercisable at March 31, 2017		655,524		$	18.31

Schedule of Nonvested Share Activity [Table Text Block]

	Unvested Stock Options					Unvested Restricted Stock				Unvested Performance Shares
	Number of Shares			Weighted-Average Grant-Date Fair Value		Number of Shares		Weighted-Average Grant-Date Fair Value		Number of Shares		Weighted- Average Grant-Date Fair Value
Unvested at December 31, 2016		817,540		$	12.50		260	$	41.05		316,750	$	30.08
Granted		39,037			21.02		-		-		-		-
Vested during period		(14,975	)		8.16		-		-		-		-
Unvested at March 31, 2017		841,602		$	12.97		260	$	41.05		316,750	$	30.08