Summary of Significant Accounting Policies - Restructuring Costs and Asset Impairment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Sep. 30, 2016
Accounting Policies [Abstract]
Non-cash restructuring costs incurred			$ 4,430
Asset impairment	$ 4,366	$ 0	4,366	$ 0
Accelerated depreciation of assets			64
Estimated exit costs			413
Impairment of machinery and equipment			2,077
Impairment of intangible assets			$ 2,289		$ 0