Equity Incentive Plans and Stock-Based Compensation (Details Textual) (USD $)	6 Months Ended	0 Months Ended	6 Months Ended		3 Months Ended		6 Months Ended			0 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended
	Jun. 30, 2014	Apr. 24, 2014 Stock Compensation Plan [Member]	Jun. 30, 2014 Stock Compensation Plan [Member]	Dec. 31, 2013 Stock Compensation Plan [Member]	Jun. 30, 2014 Employee Stock Option [Member]	Jun. 30, 2013 Employee Stock Option [Member]	Jun. 30, 2014 Employee Stock Option [Member]	Jun. 30, 2013 Employee Stock Option [Member]	Dec. 31, 2013 Employee Stock Option [Member]	Apr. 24, 2014 Employee Stock [Member]	Sep. 27, 2013 Employee Stock [Member]	Jun. 30, 2014 Employee Stock [Member]	Jun. 30, 2013 Employee Stock [Member]	Jun. 30, 2014 Employee Stock [Member]	Jun. 30, 2013 Employee Stock [Member]	Jun. 30, 2014 Restricted Stock and Stock Units [Member]	Jun. 30, 2013 Restricted Stock and Stock Units [Member]	Jun. 30, 2014 Restricted Stock and Stock Units [Member]	Jun. 30, 2013 Restricted Stock and Stock Units [Member]	Jun. 30, 2014 Stock Options with Market Condition [Member] Employee Stock Option [Member]	Dec. 31, 2013 Stock Options with Market Condition [Member] Employee Stock Option [Member]
Stock-Based Compensation
Granted (in shares)																22,868	28,456	228,676	304,952
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number					11,965,867		11,965,867		11,377,146											1,315,000	1,315,000
Shares available for issuance			11,023,718	2,527,428								1,144,644		1,144,644
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized			31,400,000
Share Based Compensation Arrangement by Share Based Payment Award Additional Number of Shares Authorized		10,000,000	10,000,000
Entity Closing Stock Price					$ 14.30		$ 14.30
Share Based Compensation Arrangement by Share Based Payment Award Options, In The Money Outstanding, Number					8,949,014		8,949,014
Share Based Compensation Arrangement By Share Based Payment Award, Options in the Money Exercisable, Number					3,031,015		3,031,015
Stock Issued During Period, Shares, Employee Stock Purchase Plans														374,588	652,272
Employee Stock Purchase Plans Price Per Share														$ 7.42	$ 4.28
Employee Stock Purchase Plan, Number Of Additional SharesToBe Authorized											1,500,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized										1,500,000
Share Based Compensation Arrangement by Share Based Payment Award Discount from Market Price Specific Date														15.00%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures			1,916,077		118,615	136,875	1,916,077	1,756,312
Estimated total grant date fair value					$ 600,000	$ 300,000	$ 7,600,000	$ 4,100,000
Stock-based compensation					2,400,000	2,500,000	4,600,000	5,600,000				1,800,000	500,000	1,900,000	1,000,000	700,000	600,000	1,300,000	1,900,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized					17,500,000		17,500,000					500,000		500,000		3,900,000		3,900,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition							2 years 4 months 2 days							4 months				2 years 4 months 20 days
Total fair value of options vested					57,000,000		57,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value					1,600,000	100,000	2,200,000	100,000
Proceeds from Stock Options Exercised							3,100,000
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	0.00%
Share Based Compensation Arrangement by Share Based Payment Award Equity Instruments Other than Options Nonvested Requisite Service Period																4 years
Share Based Compensation Arrangement by Share Based Payment Award, Equity Instruments Other than Options Nonvested Requisite Service Period for Directors																		1 year
Share Based Compensation Arrangement by Share Based Payment Award Equity Instruments Other than Options Nonvested Grants in Period Total Fair Value																$ 300,000	$ 200,000	$ 2,100,000	$ 1,700,000