Note 12 - Equity Incentive Plan (Tables)

12 Months Ended

Dec. 31, 2014

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	December 31,
	2014			2013			2012
Risk free interest rate	1.16%	to	1.39%	0.61%	to	1.02%	0.63%	to	0.64%
Expected volatility	53.28%	to	57.05%	53.60%	to	57.60%		57.60%
Expected lives (years)		4			4			4
Expected dividend yield		0.00%			0.00%			0.00%

Schedule of Share-based Compensation, Stock Options and Stock Appreciation Rights Award Activity [Table Text Block]

	2014					2013
	Number of Shares			Weighted Average Exercise Price Per Share		Number of Shares			Weighted Average Exercise Price Per Share
Options and SAR's outstanding at beginning of year		1,513,326		$	9.14		1,793,685		$	8.30
Granted		179,240		$	35.62		413,500		$	12.55
Cancelled		(53,325	)	$	23.73		(243,724	)	$	8.77
Expired		(24,292	)	$	9.87		(9,928	)	$	9.62
Exercised		(763,662	)	$	7.95		(440,207	)	$	8.71
Options and SAR's outstanding at end of year		851,287		$	14.85		1,513,326		$	9.14

Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]

	2014					2013
	Number of Shares			Weighted Average Grant Date Fair Value		Number of Shares			Weighted Average Grant Date Fair Value
Nonvested at Beginning of year		79,591		$	11.93		68,956		$	6.87
Granted		60,098		$	32.02		36,220		$	17.00
Cancelled		(7,500	)	$	25.46		-		$	-
Expired		-		$	-		-		$	-
Vested/Released		(22,575	)	$	10.01		(25,585	)	$	5.95
Nonvested at end of year		109,614		$	23.91		79,591		$	11.93