Stockholders' Equity (Tables)

6 Months Ended

Jun. 30, 2013

Stock-Based Compensation

Activity Under Equity Award Plans And Related Information [Table Text Block]

A summary of the Company’s activity under its equity award plans and related information is as follows (in thousands, except per share data):

			Options Outstanding
	Shares Available for Grant		Number of Shares		Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Life in Years	Aggregate Intrinsic Value
Balance - December 31, 2012	3,023		5,710		$	8.85
Shares authorized	1,000		—		—
Options granted	(100	)	100		13.26
Options exercised	—		(823	)	3.39
Options forfeited	315		(315	)	10.50
Restricted stock units granted	(2,037	)	—		—
Restricted stock units forfeited	235		—		—
Balance - June 30, 2013	2,436		4,672		9.79		7.5	$	35,879
Vested and exercisable - June 30, 2013			1,970		10.06		7.2	15,377
Vested and expected to vest - June 30, 2013			4,359		9.80		7.5	33,597

Restricted Stock Unit Activity [Table Text Block]

The summary of restricted stock unit activity is as follows:

	Number of Shares		Weighted-Average Grant Date Fair Value		Aggregate Intrinsic Value
Non-vested units - December 31, 2012	471		$	17.27
Granted	2,037		10.51
Vested	(183	)	14.67
Forfeited	(235	)	12.39
Non-vested units - June 30, 2013	2,090		11.46		$	35,107

Weighted-Average Assumptions Used To Estimate The Fair Value Of Stock Options [Table Text Block]

	Three Months Ended June 30,						Six Months Ended June 30,
	2013			2012			2013			2012
Dividend yield	—		%	—		%	—		%	—		%
Risk-free rate	0.93		%	0.91		%	0.93		%	1.11		%
Expected volatility	61		%	62		%	61		%	61		%
Expected term (in years)	6.1			5.6			6.1			6.0
Grant date fair value	$	7.39		$	8.74		$	7.39		$	9.02