Note 8 - Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2014

Note 8 - Stock-Based Compensation (Tables) [Line Items]

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

	Six Months Ended June 30,
	2014					2013
	Shares			Weighted- Average Exercise Price		Shares			Weighted- Average Exercise Price
Beginning Balance		501,334		$	10.34		722,155		$	10.18
Issued		21,000			32.77		3,300			20.03
Exercised		(24,897	)		12.25		(89,911	)		8.43
Forfeited		(110	)		5.76		(1,870	)		7.88
Expired		(408	)		9.37		(15,640	)		10.79
Ending Balance		496,919		$	11.20		618,034		$	10.48

Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block]

						Weighted-Average
Outstanding:		Stock Options		Weighted-Average		Remaining
Range of Exercise Prices		Outstanding		Exercise Price		Contractual Life
$5.76	$8.00		237,579	$	5.76		4.53
$8.01	$10.00		59,344		9.79		0.52
$10.01	$20.00		109,994		12.55		3.29
$20.01	$33.44		90,002		24.81		3.36
			496,919	$	11.20		3.57

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

	Six Months Ended			Years Ended December 31,
	June 30, 2014			2013			2012
Expected Volatility		34.25	%		34.12	%		36.64	%
Weighted-Average Volatility		34.24	%		34.12	%		36.64	%
Expected Dividends		0.0	%		0.0	%		0.0	%
Expected Term (In years)		7.5			7.5			7.5
Risk-Free Rate		2.11	%		1.31	%		1.13	%
Weighted-Average Fair Value (Grant date)	$	13.49		$	7.83		$	6.35

Schedule of Share-based Compensation, Restricted Stock Units Award Activity [Table Text Block]

	Six Months Ended June 30,
	2014					2013
	Shares			Weighted-Average Grant Date Fair Value		Shares			Weighted-Average Grant Date Fair Value
Unvested at Beginning		614,580		$	18.71		348,353		$	13.79
Issued		78,947			33.24		424,450			20.64
Forfeited		(832	)		23.59		(269	)		13.23
Vested		(184,921	)		17.54		(156,905	)		13.04
Unvested at End		507,774		$	21.39		615,629		$	18.71

Exercisable Stock Options [Member]

Note 8 - Stock-Based Compensation (Tables) [Line Items]

Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block]

Exercisable:		Stock Options		Weighted-Average
Range of Exercise Prices		Exercisable		Exercise Price
$5.76	$8.00		180,669	$	5.76
$8.01	$10.00		59,344		9.79
$10.01	$20.00		88,556		12.73
$20.01	$33.44		66,362		22.48
			394,931	$	10.74