Stockholders' Equity (Details Textual) (USD $)	1 Months Ended		9 Months Ended		104 Months Ended	12 Months Ended	1 Months Ended		9 Months Ended				9 Months Ended		9 Months Ended	12 Months Ended		1 Months Ended					9 Months Ended	1 Months Ended			1 Months Ended					9 Months Ended			1 Months Ended
	Oct. 31, 2008	Aug. 31, 2004	Dec. 31, 2013 Approved_Plan	Dec. 31, 2012	Mar. 31, 2013	Mar. 31, 2013 RSU plan post May 2006 [Member]	May 31, 2013 Minimum [Member] FY2014 Short Term Plan [Member]	May 31, 2013 Maximum [Member] FY2014 Short Term Plan [Member]	Dec. 31, 2012 Employee Stock Purchase Plan [Member]	Dec. 31, 2013 Employee Stock Purchase Plan [Member] 2012 Employee Stock Purchase Plan [Member]	Dec. 31, 2012 Employee Stock Purchase Plan [Member] 2012 Employee Stock Purchase Plan [Member]	Aug. 30, 2012 Employee Stock Purchase Plan [Member] 2012 Employee Stock Purchase Plan [Member]	Dec. 31, 2012 Employee Stock Purchase Plan [Member] 1998 Employee Stock Purchase Plan [Member]	Aug. 30, 2010 Employee Stock Purchase Plan [Member] 1998 Employee Stock Purchase Plan [Member]	Dec. 31, 2013 Restricted Stock Units [Member]	Mar. 31, 2013 Restricted Stock Units [Member] RSU plan prior to May 2006 [Member]	Mar. 31, 2013 Restricted Stock Units [Member] RSU plan post May 2006 [Member] quarter	Nov. 30, 2011 Restricted Stock Units [Member] Minimum [Member] November 2011 and February 2012 Plan [Member]	Nov. 30, 2011 Restricted Stock Units [Member] Maximum [Member] November 2011 and February 2012 Plan [Member]	May 31, 2012 Performance-Based RSU [Member]	Feb. 29, 2012 Performance-Based RSU [Member] milestone	Nov. 30, 2011 Performance-Based RSU [Member]	Dec. 31, 2013 Performance-Based RSU [Member] milestone	Apr. 30, 2011 Performance-Based RSU [Member] April 2011 Plan [Member]	Feb. 29, 2012 Performance-Based RSU [Member] November 2011 and February 2012 Plan [Member]	Jun. 30, 2012 Common Stock Subject to Repurchase [Member]	May 31, 2013 Performance-Based MSU [Member] Minimum [Member]	May 31, 2013 Performance-Based MSU [Member] Maximum [Member]	Nov. 30, 2013 Officer [Member] Restricted Stock Units [Member]	Nov. 30, 2013 Officer [Member] Performance-Based RSU [Member]	Feb. 29, 2012 Officer [Member] Performance-Based RSU [Member]	Dec. 31, 2013 Veloce Technologies, Inc. [Member]	Dec. 31, 2012 Veloce Technologies, Inc. [Member]	May 17, 2009 Veloce Technologies, Inc. [Member]	May 31, 2012 First Vesting Period [Member]	May 31, 2013 First Vesting Period [Member] Performance-Based MSU [Member]	May 31, 2012 Second Vesting Period [Member]	May 31, 2013 Second Vesting Period [Member] Performance-Based MSU [Member]
Stockholders Equity [Line Items]
Preferred stock, shares authorized for issuance			2,000,000		2,000,000
Preferred stock, shares outstanding			0		0
Common stock, shares authorized			375,000,000		375,000,000
Common stock, shares issued			74,171,000		67,952,000
Common stock reserved for issuance														6,300,000
Shares available for future issuance										800,000		1,800,000
Percentage of purchase price of common stock equal to fair market value										85.00%
Common stock, shares issued, employee stock purchase plan									0	300,000	0		400,000
Stock repurchase program, authorized amount		$ 200,000,000.0	$ 15,900,000
Increase in the amount authorized for stock purchase program	100,000,000.0
Stock repurchase program, shares repurchased			0	100,000	17,300,000
Stock repurchase program, weighted average price per share				$ 5.18	$ 10.04
Number of stockholder-approved plans			3
Number of plans unapproved by stockholders			4
Award expiration period, in years																				12 years		18 months		3 years	18 months
Vesting period, in years																4 years	4 years	1 year	18 months	1 year
Vested in first period of employment						0
Shares outstanding			2,471,000		3,492,000																					0
Weighted average remaining contractual term for options outstanding			2 years 9 months 12 days
Aggregate pretax intrinsic value of options exercised			1,700,000
Pre-tax intrinsic value of options outstanding			9,000,000
Pre-tax intrinsic value of options exercisable			8,400,000
Common stock, closing price per share			$ 13.37
Award vesting period, quarters																	12
Restricted stock units awarded															3,069,000														500,000	300,000	500,000
Number of milestones																					3
Grants in period, fair value																														3,200,000	3,700,000
Restricted stock units vested															2,048,000														200,000
Number of milestones completed																							2
Award performance period																																				2 years		3 years
Award vesting percentage																											0.00%	150.00%
Award pay out percentage							50.00%	150.00%
Weighted average remaining contractual term for the restricted stock units outstanding, in years			1 year 0 months 12 days
Aggregate pre-tax intrinsic value of restricted stock units outstanding which includes performance based awards which are subject to milestone attainments			79,600,000
Share Based Compensation Arrangement by Share Based Payment Award Equity Other than Options Aggregate Pre Tax Intrinsic Value Released			18,800,000
Number of years of development work to be performed																																		5 years
Stock-based compensation expense related to the acceleration of Veloce warrants			$ 0	$ 1,289,000																												$ 1,300,000	$ 1,300,000
Award vesting percentage																																			66.67%		33.33%