Restructuring and Separation Expenses (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Jun. 30, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Restructuring and Related Activities [Abstract]
Restructuring and separation costs incurred			$ 787	$ 1,322	$ 8,441
Separation costs	$ 3,800				$ 7,900
Restructuring costs related to exited Canadian facility lease		$ 500