Basis of Presentation and Summary of Significant Accounting Policies - Concentration risk (Detail)	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Concentration Risk [Line Items]
Number Of Major Customer	3	3
Accounts Receivable | Credit Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	58.00%	72.00%
Customer A | Sales Revenue, Goods, Net | Customer Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	22.00%	25.00%	25.00%
Customer B | Sales Revenue, Goods, Net | Customer Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	15.00%	17.00%	15.00%
Customer C | Sales Revenue, Goods, Net | Customer Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	13.00%	11.00%	11.00%
Customer C | Accounts Receivable | Credit Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	10.00%	10.00%
Major Customer Two | Accounts Receivable | Credit Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	17.00%	26.00%
Major Customer One | Accounts Receivable | Credit Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage		36.00%
Major Customer | Accounts Receivable | Credit Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	31.00%
Supplier One | Accounts Payable | Supplier Concentration Risk
Concentration Risk [Line Items]
Number of Major Suppliers	2	2
Concentration risk, percentage	49.00%	49.00%
Supplier Two | Accounts Payable | Supplier Concentration Risk
Concentration Risk [Line Items]
Number of Major Suppliers	4	4
Concentration risk, percentage	75.00%	75.00%