Income Taxes (Details 7) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Income Taxes
Effective income tax rate (as a percent)	(29.80%)	29.80%	27.80%
Unrecognized tax benefits, recognition of which would have an effect on provision for income taxes and effective income tax rate	$ 5,961	$ 10,263
Accrued interest	332
Accrued penalties	174
Liability of unrecognized tax benefits	$ 8,029	$ 13,635	$ 12,888	$ 10,687