Description of Business (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended			0 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011	Jun. 12, 2013 IPO [Member]	Sep. 20, 2013 Follow on Public Offering [Member]	Jun. 12, 2013 Common Stock [Member] IPO [Member]	Sep. 20, 2013 Common Stock [Member] Follow on Public Offering [Member]
Description of Business [Line Items]
Accumulated deficit	$ (178,136)	$ (141,252)
Shares of stock issued				750,000		5,750,000	1,687,000
Aggregate offering price, net of issuance costs	138,613	0	0		61,221	80,213	61,221
Underwriting discounts and commissions						6,037	2,885
Deferred offering costs						$ 2,504	$ 1,442