Stock Based Compensation and Stock Options - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Class of Stock [Line Items]
Common stock grants	19,365,500		19,365,500
Stock options vested, percent			25.00%
Remaining vested options, percent			75.00%
Options for employees expiring from date of grant, period			5 years
Options for board of directors expiring from date of grant, period			10 years
Options expected forfeiture rate, percentage	12.73%	11.86%
Stock-based compensation expense			$ 870,000	$ 387,000
Weighted-average grant-date fair value of options granted	$ 13.89	$ 8.67
Recognized stock compensation expense	82,000	0
Time Based Options [Member] | Performance Based Options [Member]
Class of Stock [Line Items]
Stock-based compensation expense	$ 465,000	$ 89,000	$ 870,000	$ 387,000
Minimum [Member]
Class of Stock [Line Items]
Non-statutory stock options vesting period			1 year
Maximum [Member]
Class of Stock [Line Items]
Non-statutory stock options vesting period			36 months