Income Taxes - Components of Income Tax Provision (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Current:
Federal	$ 1,092	$ 11,120	$ (42,001)
State and foreign	6,359	3,193	2,000
Total	7,451	14,313	(40,001)
Deferred:
Federal	5,190	(3,766)	16,580
State and foreign	(1,435)	(1,186)	9,396
Total	3,755	(4,952)	25,976
Total income tax expense (benefit)	$ 11,206	$ 9,361	$ (14,025)