Equity Award Plans - Additional Information (Details) (USD $) In Thousands, except Share data, unless otherwise specified	6 Months Ended
	Mar. 31, 2014 Executives	Mar. 31, 2013
Deferred Compensation Arrangement With Individual Share Based Payments [Line Items]
Number of executive officers granted performance based RSU	4
Exercise of stock options, shares	152,899	85,949
Aggregate exercise price	$ 1,690	$ 618
Net-share settled by company	53,720	30,996
Repurchase of common stock, shares	57,036	30,310
Payments for tax obligation to the tax authorities on exercise or vesting date	$ 1,795	$ 615