Stockholder's Equity and Stock Based Compensation (Details 1) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Additional information
Closing stock price (in dollars per share)	$ 28.06		$ 28.06
Minimum
Valuation assumptions
Expected term			6 months	6 months
Maximum
Valuation assumptions
Expected term				9 months
Employee Stock Purchase Plan
Additional information
Average purchase price of shares issued (in dollars per share)	$ 23.87		$ 23.87
Issuance of common stock under employee stock purchase plan			100
Employee Stock Purchase Plan | Minimum
Valuation assumptions
Risk-free interest rate (as a percent)			0.05%	0.08%
Expected volatility (as a percent)			39.00%	41.00%
Expected dividend rate (as a percent)			0.00%	0.00%
Employee Stock Purchase Plan | Maximum
Valuation assumptions
Risk-free interest rate (as a percent)			0.07%	0.11%
Expected volatility (as a percent)			43.00%	42.00%
Estimate of fair value of options member | Minimum
Valuation assumptions
Expected term	6 years	6 years	6 years	6 years
Risk-free interest rate (as a percent)	1.70%	1.90%	1.70%	1.84%
Expected volatility (as a percent)	44.80%	49.00%	44.80%	49.00%
Expected dividend rate (as a percent)	0.00%	0.00%	0.00%	0.00%
Estimate of fair value of options member | Maximum
Valuation assumptions
Risk-free interest rate (as a percent)	0.00%	1.97%	0.00%	1.97%
Expected volatility (as a percent)	0.00%	55.00%	0.00%	56.00%
Stock options to purchase common stock
Additional information
Closing stock price (in dollars per share)	$ 28.06		$ 28.06
RSUs
Number of RSUs
Balance at the beginning of the period (in shares)			2,360
RSUs Granted (in shares)			1,256
RSUs Vested (in shares)			(299)
RSUs Cancelled/Forfeited (in shares)			(367)
Balance at the end of the period (in shares)	2,950		2,950
Average Grant Date Fair Value
Balance at the beginning of the period (in dollars per share)			$ 33.30
RSUs Granted (in dollars per share)			33.65	$ 38.29
RSUs Vested (in dollars per share)			36.94
RSUs Cancelled/Forfeited (in dollars per share)			32.39
Balance at the end of the period (in dollars per share)	$ 33.19		$ 33.19
Aggregate Intrinsic Value
Balance at the beginning of the period (in dollars)			$ 77,207
Balance at the end of the period (in dollars)	$ 82,763		$ 82,763
Additional information
RSUs Granted (in dollars per share)			$ 33.65	$ 38.29
Total intrinsic value of vested RSUs			$ 8,472	$ 4,237
Closing stock price (in dollars per share)	$ 28.06		$ 28.06
RSUs | Minimum
Aggregate Intrinsic Value
Vesting period			3 years
RSUs | Maximum
Aggregate Intrinsic Value
Vesting period			4 years