Equity Incentive Plans and Stock-Based Compensation (Details 3) (USD $)	0 Months Ended	3 Months Ended
	Sep. 27, 2013	Mar. 31, 2014	Mar. 31, 2013
Valuation assumptions
Dividend yield (as a percent)		0.00%
Employee Stock Purchase Plan
Stock-Based Compensation
Shares available for issuance		19,232
Number of additional shares registered under the ESPP	1,500,000
Shares issued at discount from the fair market value (as a percent)		15.00%
Stock-based compensation			$ 500,000
Expected weighted-average period for recognition of compensation cost		1 month
Stock Option Plans
Stock-Based Compensation
Stock options granted (in shares)		1,797,462	1,619,437
Estimated total grant date fair value		7,000,000	3,800,000
Stock-based compensation		2,200,000	3,100,000
Unrecognized compensation cost net of expected forfeitures		19,400,000
Expected weighted-average period for recognition of compensation cost		2 years 6 months 11 days
Total fair value of options vested		63,400,000
Total intrinsic value of options exercised		600,000
Proceeds from Stock Options Exercised		1,400,000
Valuation assumptions
Expected stock price volatility (as a percent)		44.00%	47.00%
Risk free interest rate		2.10%	0.90%
Expected term		6 years 0 months 29 days	5 years 4 months 24 days
Weighted-average fair value of stock options granted (in dollars per share)		$ 3.92	$ 2.33
Restricted Stock and Stock Units
Stock-Based Compensation
Stock-based compensation		700,000	1,300,000
Unrecognized compensation cost net of expected forfeitures		4,300,000
Expected weighted-average period for recognition of compensation cost		2 years 7 months 6 days
Valuation assumptions
General nonvested equity stock service period (in years)		4 years
Nonvested equity stock unit to directors, service period		1 year
Total fair value of nonvested equity stock units at grant date		$ 1,800,000	$ 1,500,000
Nonvested equity stock and stock units
Nonvested at the beginning of the period (in shares)		629,649
Granted (in shares)		205,808	276,496
Vested (in shares)		(117,828)
Forfeited (in shares)		(13,078)
Nonvested at the end of the period (in shares)		704,551
Weighted-Average Grant-Date Fair Value
Nonvested at the beginning of the period (in dollars per share)		$ 8.56
Granted (in dollars per share)		$ 8.79
Vested (in dollars per share)		$ 9.56
Forfeited (in dollars per share)		$ 6.67
Nonvested at the end of the period (in dollars per share)		$ 8.49