Inventory - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012
Inventory [Line Items]
Inventory write-down	$ 100	$ 500	$ 287	$ 957