Income Taxes (Narrative) (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Mar. 31, 2019	Sep. 30, 2017	Sep. 30, 2018
Income Tax Expense (Benefit) [Line Items]
Corporate income tax rate	21.00%	35.00%
Valuation allowance	$ 1.6
Alternative Minimum Tax [Member]
Income Tax Expense (Benefit) [Line Items]
Operating loss carryforwards			$ 0.5
Foreign Tax Authority [Member]
Income Tax Expense (Benefit) [Line Items]
Operating loss carryforwards			62.3
Federal [Member]
Income Tax Expense (Benefit) [Line Items]
Operating loss carryforwards			33.2
Federal [Member] | 2022 to 2037 [Member]
Income Tax Expense (Benefit) [Line Items]
Operating loss carryforwards			14.4
Federal [Member] | Indefinite [Member]
Income Tax Expense (Benefit) [Line Items]
Operating loss carryforwards			18.8
State [Member]
Income Tax Expense (Benefit) [Line Items]
Operating loss carryforwards			36.2
State [Member] | 2022 to 2037 [Member]
Income Tax Expense (Benefit) [Line Items]
Operating loss carryforwards			19.6
State [Member] | Indefinite [Member]
Income Tax Expense (Benefit) [Line Items]
Operating loss carryforwards			$ 16.6