Equity (Schedule of Earnings per Share) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Equity [Abstract]
Numerator - Net (loss) income	$ (5,432)	$ 11,697	$ (7,486)	$ 14,523
Less: Undistributed earnings allocated to participating securities	0	(94)	0	(118)
Undistributed earnings allocated to common shareholders for basic net (loss) income per share	(5,432)	11,603	(7,486)	14,405
Undistributed earnings allocated to common shareholders for diluted net (loss) income per share	$ (5,432)	$ 11,603	$ (7,486)	$ 14,405
Denominator:
Denominator for basic net (loss) income per share - weighted average shares outstanding	30,392	26,310	30,162	26,142
Dilutive options outstanding, unvested stock units and ESPP	0	332	0	290
Denominator for diluted net (loss) income per share - adjusted weighted average shares outstanding	30,392	26,642	30,162	26,432
Basic net income (loss) per share (in dollars per share)	$ (0.18)	$ 0.44	$ (0.25)	$ 0.55
Diluted net income (loss) per share (in dollars per share)	$ (0.18)	$ 0.44	$ (0.25)	$ 0.54
Weighted average antidilutive options, unvested restricted stock units and awards, warrants and ESPP shares excluded from the computation	3,028	1,869	2,653	2,265
Average market price of common stock (in dollars per share)	$ 4.96	$ 5.66	$ 5.00	$ 5.16