Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Sep. 30, 2018
Income Tax Contingency [Line Items]
Income tax expense	$ 600	$ 1,240
Unrecognized tax benefits that would impact effective tax rate	1,200		$ 1,200
Unrecognized tax benefits, income tax penalties and interest accrued	$ 700		$ 700
Minimum
Income Tax Contingency [Line Items]
Number of years open for tax examinations	3 years
Maximum
Income Tax Contingency [Line Items]
Number of years open for tax examinations	5 years