Income Taxes - Income Taxes Narrative (Details) - USD ($)		12 Months Ended
	Dec. 22, 2017	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Income Tax Disclosures
Operating Loss Carryforwards, Limitations on Usage		$ 19,600,000
Undistributed Earnings of Foreign Subsidiaries		$ 50,900,000
Newly Enacted Tax Rate			21.00%
Pre-December 22, 2017 Federal statutory rate	35.00%
Fiscal 2018 Blended Tax Rate		24.50%
Tax Benefit Due to Newly Enacted Tax Rate		$ 200,000	$ 281,200,000
Tax (Benefit) Expense Due to One-Time Transition Tax		(4,600,000)	$ 10,300,000
Domestic Tax Authority
Income Tax Disclosures
Operating Loss Carryforwards		47,200,000
State and Local Jurisdiction
Income Tax Disclosures
Operating Loss Carryforwards		604,900,000
Foreign Tax Authority
Income Tax Disclosures
Operating Loss Carryforwards		$ 9.1
UNITED STATES
Income Tax Disclosures
Pre-December 22, 2017 Federal statutory rate		21.00%		35.00%
Fiscal 2018 Blended Tax Rate			24.50%