Equity - Schedule of Earnings per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Numerator:
Numerator - Net income (loss)	$ 15,488	$ (3,150)	$ (5,432)	$ (2,054)	$ (2,252)	$ (7,283)	$ 11,697	$ 2,826	$ 4,852	$ 4,988	$ (39,171)
Less: Undistributed earnings allocated to participating securities									(6)	(26)	0
Undistributed earnings allocated to common shareholders for basic net income (loss) per share									4,846	4,962	(39,171)
Undistributed earnings allocated to common shareholders for diluted net income (loss) per share									$ 4,846	$ 4,962	$ (39,171)
Denominator:
Denominator for basic net income (loss) per share - weighted average shares outstanding	30,752	30,656	30,392	29,938	27,158	26,609	26,310	25,977	30,453	26,531	23,559
Dilutive options outstanding, unvested stock units and ESPP									324	281	0
Denominator for diluted net income (loss) per share - adjusted weighted average shares outstanding	30,992	30,656	30,392	29,938	27,158	26,609	26,642	26,236	30,777	26,812	23,559
Basic net income (loss) per share (in dollars per share)	$ 0.50	$ (0.10)	$ (0.18)	$ (0.07)	$ (0.08)	$ (0.27)	$ 0.44	$ 0.11	$ 0.16	$ 0.19	$ (1.66)
Diluted net income (loss) per share (in dollars per share)	$ 0.50	$ (0.10)	$ (0.18)	$ (0.07)	$ (0.08)	$ (0.27)	$ 0.44	$ 0.11	$ 0.16	$ 0.19	$ (1.66)
Weighted average antidilutive options, unvested restricted stock units and awards, warrants and ESPP shares excluded from the computation (in shares)									1,936	2,391	3,999
Average market price of common stock (in dollars per share)									$ 4.69	$ 4.64	$ 4.44