Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Income Tax Contingency [Line Items]
Income tax benefit from discontinued operations		$ 1,300
Statutory tax rate based on blended rate calculation	35.00%	21.00%	24.30%	34.00%
Additions to valuation allowance		$ 131	$ 839
Operating loss carryforwards, annual utilization limits		$ 800
Operating loss carryforwards, utilization limit, percent		80.00%
Unrecognized tax benefits that would impact effective tax rate		$ 600
Net expense (benefit) for interest and penalties		100	(2,000)	$ 400
Cumulative accrual for potential interest and penalties		$ 800	$ 700
Maximum
Income Tax Contingency [Line Items]
Number of years open for tax examinations		5 years
Minimum
Income Tax Contingency [Line Items]
Number of years open for tax examinations		3 years
Federal
Income Tax Contingency [Line Items]
Net operating loss carryforwards		$ 13,800
Net operating loss carryforwards with indefinite carryforward period		19,500
Foreign Tax Authority
Income Tax Contingency [Line Items]
Net operating loss carryforwards		38,400
State Jurisdiction
Income Tax Contingency [Line Items]
Net operating loss carryforwards		$ 12,600