(8) Concentrations (Detail) (USD $)	3 Months Ended		9 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Mar. 31, 2012
First Major Customer [Member]
Entity-Wide Revenue, Major Customer, Amount	$ 19,401,000	$ 21,228,000	$ 61,243,000	$ 59,644,000
EntityWideRevenueMajorCustomerPercent	60.00%	59.00%	61.00%	62.00%
Accounts Receivable, Net	9,749,000	6,695,000	9,749,000	6,695,000	7,329,000
Second largest customer [Member]
Entity-Wide Revenue, Major Customer, Amount	3,650,000	3,393,000	14,830,000	10,143,000
EntityWideRevenueMajorCustomerPercent	11.00%	9.00%	15.00%	11.00%
Accounts Receivable, Net	1,994,000	1,998,000	1,994,000	1,998,000	1,504,000
Third Largest Customer [Member]
Entity-Wide Revenue, Major Customer, Amount		4,923,000		8,459,000
EntityWideRevenueMajorCustomerPercent		14.00%		9.00%
Accounts Receivable, Net		$ 14,000		$ 14,000