Note 2 - Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2013

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

	Three months ended March 31,
	2013		2012
Non-employee	$	-	$	5
ESPP		192		211
Restricted stock		4,134		2,180
Stock options		334		919
	$	4,660	$	3,315

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

	Three months ended March 31,
	2013			2012
Expected term (years)		3.9			4.1
Expected volatility		50.5	%		53.4	%
Risk-free interest rate		0.6	%		0.6	%
Dividend yield		-			-

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

	RSUs			Weighted Average Grant Date Fair Value Per Share		PSUs			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, 2013		1,098,563		$	16.96		531,185		$	18.49		1,629,748		$	17.46		2.18
Awards granted		239,388			23.84		311,540			24.35		550,928			24.13
Performance awards adjustment (1)		-			-		49,972			17.55		49,972			17.55
Awards released		(161,078	)		16.51		(206,409	)		18.90		(367,487	)		17.85
Awards forfeited		(65,374	)		16.52		(27,056	)		17.91		(92,430	)		16.93
Outstanding at March 31, 2013		1,111,499		$	18.53		659,232		$	21.09		1,770,731		$	19.48		2.31

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

Available shares as of January 1, 2013	4,217,960
Additions to plan	713,466
Purchases	(65,247	)
Available shares as of March 31, 2013	4,866,179

Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Method Used

	Three months ended March 31,
	2013			2012
Expected term (years)		0.5			0.5
Expected volatility		28.5	%		50.7	%
Risk-free interest rate		0.1	%		0.1	%
Dividend yield		-			-

Unit Activity [Member]

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

Available for grant as of January 1, 2013	4,957,244
Additions to plan	1,783,664
Grants	(550,928	)
Performance awards adjustment	(49,972	)
Cancellations	261,755
Available for grant as of March 31, 2013	6,401,763

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, 2013 (3,603,762 options exercisable at a weighted-average exercise price of $15.59 per share)		3,813,361		$	15.62		2.56	$	25,379,573
Options granted		-			-
Options exercised		(626,970	)		15.69
Options forfeited and expired		(169,325	)		15.18
Outstanding at March 31, 2013		3,017,066		$	15.63		2.31	$	26,390,327
Options exercisable at March 31, 2013 and expected to become exercisable		3,006,437		$	15.63		2.30	$	26,290,048
Options vested and exercisable at March 31, 2013		2,848,738		$	15.61		2.17	$	24,966,361