Stock-based Compensation - Stock-based Compensation Expenses (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expenses	$ 813	$ 392
Product costs [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expenses	4	3
Research and development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expenses	52	23
Selling, general and administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expenses	$ 757	$ 366