Note 9 - Stock Based Compensation (Tables)

9 Months Ended

Sep. 30, 2015

Notes Tables

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

Options	Number of Shares			Weighted Average Exercise Price
Outstanding at December 31, 2014		2,070,672		$	12.08
Granted		29,500		$	23.45
Exercised		(212,276	)	$	7.25
Forfeited or expired		(80,375	)	$	14.48
Outstanding at March 31, 2015		1,807,521		$	12.72
Granted		23,818		$	41.11
Exercised		(62,625	)	$	5.68
Outstanding at June 30, 2015		1,768,714		$	13.35
Exercised		(157,850	)	$	6.74
Outstanding at September 30, 2015		1,610,864		$	14.00
Exercisable at September 30, 2015		577,796		$	10.16

Schedule of Nonvested Share Activity [Table Text Block]

	Nonvested Stock Options					Nonvested Restricted Stock
	Number of Shares			Weighted-Average Grant-Date Fair Value		Number of Shares		Weighted-Average Grant-Date Fair Value
Nonvested at December 31, 2014		1,098,875		$	7.14		-	$	-
Granted		29,500		$	9.25		-	$	-
Vested		(27,500	)	$	4.02		-	$	-
Forfeited		(80,375	)	$	6.90		-	$	-
Nonvested at March 31, 2015		1,020,500		$	7.30		-	$	-
Granted		23,818		$	12.24		8,897	$	39.34
Vested		(11,250	)	$	7.32		-	$	-
Nonvested at June 30, 2015		1,033,068		$	7.41		8,897	$	39.34
Nonvested at September 30, 2015		1,033,068		$	7.41		8,897	$	39.34