Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016	Sep. 30, 2016
Effective tax rate	17.70%	21.40%	24.90%	22.10%
Current Income Tax Expense (Benefit)			$ 3.5
Retroactive reinstatement of research tax credit, benefit			$ 2.0
Foreign Tax Authority [Member] | France [Member]
Federal statutory income tax rate			28.00%		33.30%