Note 6 - Stockholders' Equity (Tables)

9 Months Ended

12 Months Ended

Sep. 30, 2012

Dec. 31, 2012

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]

	Year ended December 31,
	2012		2011		2010
Non-Employee	$	17	$	13	$	(7	)
ESPP		632		538		609
Restricted Stock		12,468		7,216		8,271
Stock Options		5,535		5,369		7,937
	$	18,652	$	13,136	$	16,810

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

			Options Outstanding						Options Exercisable
Range of Exercises Prices			Number of Options Outstanding as if 12/31/2012		Weighted Average Remaining Contractual Life (Years)		Weighted Average Exercise Price		Number of Options Exercisable as of 12/31/2012		Weighted Average Exercise Price
$0.76	-	$11.32		546,691		1.81	$	8.52		522,609	$	8.41
$11.44	-	$12.43		388,118		2.32	$	12.37		382,792	$	12.37
$12.52	-	$14.90		450,417		3.00	$	14.17		386,542	$	14.25
$14.94	-	$14.97		82,757		2.17	$	14.93		81,635	$	14.93
$15.03	-	$15.03		586,548		2.82	$	15.03		585,480	$	15.03
$15.14	-	$16.41		383,861		2.22	$	15.53		359,242	$	15.53
$16.51	-	$18.29		392,703		2.25	$	17.68		373,249	$	17.72
$18.63	-	$20.30		445,551		3.15	$	19.70		410,922	$	19.72
$20.41	-	$22.85		422,592		2.86	$	21.85		393,194	$	21.87
$23.03	-	$24.84		114,123		2.76	$	24.18		108,097	$	24.24
				3,813,361						3,603,762

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

	2012			2011			2010
Expected term (years)		4.1			4.1			4.1
Expected volatility		53.4	%		52.9	%		55.9	%
Risk-free interest rate		0.6	%		1.1	%		1.8	%
Dividend yield		-			-			-

	2012			2011			2010
Expected term (years)		0.5			0.5			0.5
Expected volatility		45.8	%		39.2	%		39.5	%
Risk-free interest rate		0.1	%		0.1	%		0.2	%
Dividend yield		-			-			-

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

	Restricted Stock Awards			Weighted Average Grant Date Fair Value Per Share		Weighted Average Remaining Recognition Period (Years)
Outstanding at January 1, 2010		6,550		$	16.62		0.14
Awards released		(6,550	)		16.62
Outstanding at December 31, 2010		-		$	-		-
Outstanding at December 31, 2011		-		$	-		-
Outstanding at December 31, 2012		-		$	-		-

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

	Restricted Stock Units			Weighted Average Grant Date Fair Value Per Share		Performance-Based Restricted Stock Units			Weighted Average Grant Date Fair Value Per Share		Total			Weighted Average Grant Date Fair Value Per Share		Weighted Average Remaining Recognition Period (Years)
Outstanding at January 1, 2010		289,896		$	18.67		-		$	-		289,896		$	18.67		2.22
Awards granted		518,240			19.50		416,000			20.73		934,240			20.05
Awards released		(158,499	)		18.56		(72,375	)		20.73		(230,874	)		19.24
Awards forfeited		(33,088	)		18.38		-			-		(33,088	)		18.38
Outstanding at December 31, 2010		616,549		$	19.41		343,625		$	20.73		960,174		$	19.88		2.91
Awards granted		853,480			14.40		-			-		853,480			14.40
Awards released		(310,976	)		17.78		(102,125	)		20.73		(413,101	)		18.51
Awards forfeited		(76,622	)		18.39		(24,375	)		20.73		(100,997	)		18.95
Outstanding at December 31, 2011		1,082,431		$	16.00		217,125		$	20.73		1,299,556		$	16.87		2.71
Awards modification (1)		(76,500	)		15.69		76,500			15.69		-			-
Awards granted (2)		617,084			18.69		356,752			18.38		973,836			18.57
Performance awards adjustment (3)		-			-		(18,359	)		19.18		(18,359	)		19.18
Awards released		(447,096	)		17.30		(96,500	)		20.73		(543,596	)		17.91
Awards forfeited		(77,356	)		16.61		(4,333	)		19.07		(81,689	)		16.74
Outstanding at December 31, 2012		1,098,563		$	16.96		531,185		$	18.49	$	1,629,748		$	17.46		2.18

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

Available shares as of January 1, 2012	3,693,210
Additions to plan	676,520
Purchases	(151,770	)
Available shares as of December 31, 2012	4,217,960

Unit Activity [Member]

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

Available for grant as of January 1, 2012	4,291,737
Additions to plan	1,641,301
Grants	(1,152,320	)
Performance awards adjustment	18,359
Cancellations	158,167
Available for grant as of December 31, 2012	4,957,244

Plan Status [Member]

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

	Stock Options				Weighted Average Exercise Price			Weighted Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value
Outstanding at January 1, 2010 (4,112,763 options exercisable at a weighted-average exercise price of $10.93 per share)		7,410,914			$	13.48			5.04	$	77,918,848
Options granted (weighted-average fair value of $8.95 per share)		370,500				19.92
Options exercised		(1,452,245	)			9.87
Options forfeited and expired		(494,051	)			15.67
Outstanding at December 31, 2010 (4,264,268 options exercisable at a weighted-average exercise price of $13.33 per share)		5,835,118			$	14.61			4.30	$	19,035,591
Options granted (weighted-average fair value of $5.85 per share)		152,500				13.96
Options exercised		(685,417	)			6.85
Options forfeited and expired		(438,962	)			18.66
Outstanding at December 31, 2011 (4,202,786 options exercisable at a weighted-average exercise price of $15.05 per share)		4,863,239			$	15.31			3.44	$	8,817,049
Options granted (weighted-average fair value of $8.22 per share)		178,484		(1)		15.63
Options exercised		(1,151,884	)			11.62
Options forfeited and expired		(76,478	)			20.90
Modification adjustment		-				(0.74	)
Outstanding at December 31, 2012		3,813,361			$	15.62			2.56	$	25,379,573
Options exercisable at December 31, 2012 and expected to become exercisable		3,799,748			$	15.62			2.55	$	25,288,257
Options vested and exercisable at December 31, 2012		3,603,762			$	15.59			2.42	$	24,105,872