Stock-Based Compensation and Other Employee Benefit Plans - Additional Information (Detail) (USD $)	9 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Mar. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair market value of non-statutory options		85.00%
Shares authorized for issuance under the option plan		17,859,948
Percentage of option vested at one year anniversary		25.00%
Performance-based options outstanding	10,255,222	10,828,682
Option granted to purchase of common stock	3,811,236	3,176,750	3,583,419
Options exercisable, weighted average exercise price	$ 2.39	$ 9.75	$ 0.71
Common stock, Weighted average grant date fair value per share	$ 1.40	$ 10.84	$ 0.42
Options granted, total estimated fair value	$ 10,600,000	$ 34,400,000	$ 1,500,000
Stock awards, vesting period		4 years
Expected dividend yield	0.00%	0.00%	0.00%
Options to purchase shares		2,232,969
Total intrinsic value of options exercised		26,200,000
Compensation expense related to stock options	1,100,000	6,400,000
Unrecognized compensation cost		35,100,000
Unrecognized compensation cost expected period for recognition		3 years 4 months 24 days
Income tax expense (benefit) from share based compensation		$ 0
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options expiration in period from the date of grant		10 years
Performance Based Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options expiration in period from the date of grant		10 years
Performance-based options outstanding		0
Option granted to purchase of common stock			581,832
Service Based Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option granted to purchase of common stock			3,001,587
Stock awards, vesting period		4 years