Derivative Financial Instruments - Additional Information (Details) - USD ($) $ in Millions		1 Months Ended	9 Months Ended
	Jun. 30, 2017	Jul. 31, 2017	Jun. 30, 2017	Sep. 30, 2016
Canadian Dollar Forward Contract
Derivative [Line Items]
Foreign currency forward contract to hedge	$ 0.7
Foreign currency forward contract, expiry date			Sep. 30, 2017
Canadian Dollar Forward Contract | Subsequent Event
Derivative [Line Items]
Foreign currency forward contract to hedge		$ 4.3
Canadian Subsidiary
Derivative [Line Items]
Denominated intercompany accounts payable	24.9		$ 24.9	$ 24.9
Denominated intercompany accounts payable, short-term nature	0.7		0.7
Denominated intercompany accounts payable, long-term nature	$ 24.2		$ 24.2