Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Tax cuts and jobs act of 2017, provisional income tax (expense) benefit			$ 3,641
Estimated annual effective tax rate used to calculate income tax expense (benefit)			13.00%	63.10%
Federal statutory income tax rate, percent			24.50%
Effective income tax rate reconciliation, percent			31.60%	(58.90%)
Income tax (benefit) expense	$ (2,018)	$ 4,812	$ 2,393	$ 11,907
Loss before income taxes	$ 14,998	$ 83	$ 7,582	$ (20,212)