Stock Awards - Additional Information (Detail) (USD $)	6 Months Ended		12 Months Ended				6 Months Ended		12 Months Ended				12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2011 Restricted Stock Units (RSUs) [Member]	Dec. 31, 2010 Restricted Stock Units (RSUs) [Member]	Dec. 31, 2013 Restricted Stock Units (RSUs) [Member]	Dec. 31, 2012 Restricted Stock Units (RSUs) [Member]	Jun. 30, 2011 Restricted Stock Units (RSUs) [Member]	Dec. 31, 2013 2005 Stock Option Plan [Member]	Dec. 31, 2014 2012 Equity Incentive Plan [Member]	Dec. 31, 2013 2012 Equity Incentive Plan [Member]	Dec. 31, 2014 2012 Employee Stock Purchase Plan [Member]	Dec. 31, 2013 2012 Employee Stock Purchase Plan [Member]	Dec. 31, 2013 2005 Stock Plan and 2012 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Vested							0	0	322,623	0	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Total Intrinsic Value	$ 2,400,000		$ 446,054,000	$ 84,215,000	$ 7,500,000
Shares of common stock, authorized (shares)			600,000,000	600,000,000								53,731,033		21,767,792
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized													7,017,730		1,403,546
Number of shares of common stock outstanding, increase, percentage														5.00%		1.00%
Shares of common stock reserved for issuance			47,546,117													6,263,677
Stock options granted to new employees vest, percentage per annum																	25.00%
Requisite service period to vest employment continuation period																	3 years
Compensation expense recognized, vesting term			48 months						4 years
Stock options vesting period			4 years
Options granted, exercisable period			10 years
Stock-based compensation expense	5,637,000	1,121,000	65,581,000	27,937,000	2,954,000
Weighted-average grant date fair value of options granted (usd per share)	$ 7.68		$ 18.70		$ 2.52	$ 1.16
Fair value of vested shares	19,200,000		33,100,000		2,600,000	2,000,000
Total unrecognized compensation cost, adjusted for estimated forfeitures, related to unvested stock options			75,300,000
Weighted-average remaining vesting period for unvested stock options			2 years 7 months 13 days						3 years 6 months 4 days
Unrecognized compensation expense expected to be recognized									$ 145,700,000
Purchase price of common stock, percent																85.00%
ShareBasedCompensationArrangementByShareBasedPaymentAwardPurchaseOfferingPeriod																6 months