Note 6 - Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2013

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

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

	Nine Months Ended September 30,
	2013					2012
	Shares			Weighted-Average Exercise Price		Shares			Weighted-Average Exercise Price
Beginning Balance		722,155		$	10.18		919,371		$	10.23
Issued		3,300			20.03		-			-
Exercised		(117,791	)		10.58		(74,933	)		10.32
Forfeited		(1,870	)		7.88		(2,640	)		5.76
Expired		(23,113	)		10.05		(31,341	)		13.92
Ending Balance		582,681		$	10.17		810,457		$	10.09

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

Outstanding:		Stock Options		Weighted-Average		Weighted-Average Remaining
Range of Exercise Prices		Outstanding		Exercise Price		Contractual Life
$5.76	$8.00		244,190	$	5.76		5.28
$8.01	$10.00		150,988		9.22		0.70
$10.01	$20.00		110,292		12.55		4.03
$20.01	$24.46		77,211		22.57		2.19
			582,681	$	10.17		3.45

Exercisable:		Stock Options		Weighted-Average
Range of Exercise Prices		Exercisable		Exercise Price
$5.76	$8.00		144,017	$	5.76
$8.01	$10.00		150,988		9.22
$10.01	$20.00		77,715		12.93
$20.01	$24.46		73,911		22.68
			446,631	$	10.98

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

	Nine Months Ended			Years Ended December 31,
	September 30, 2013			2012			2011
Expected Volatility		34.12	%		36.64	%	33.61 %	-	36.64%
Weighted-Average Volatility		34.12	%		36.64	%		35.60%
Expected Dividends		0.0	%		0.0	%		0.0%
Expected Term (In years)		7.5			7.5		6.0	-	7.5
Risk-Free Rate		1.31	%		1.13	%		1.82%
Weighted-Average Fair Value (Grant date)	$	7.83		$	6.35			$4.61

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

	Nine Months Ended September 30,
	2013					2012
	Shares			Weighted-Average Grant Date Fair Value		Shares			Weighted-Average Grant Date Fair Value
Unvested at Beginning		348,363		$	13.79		222,795		$	10.61
Issued		424,450			20.64		268,115			15.30
Forfeited		(269	)		13.23		(12,694	)		10.52
Vested		(156,915	)		13.04		(127,506	)		11.73
Unvested at End		615,629		$	18.71		350,710		$	13.79