Property, Equipment, and Related Depreciation - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 350	$ 358	$ 1,033	$ 1,051
Expected net sale proceeds			$ 3,800