Product Warranties (Details) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward]
Balance at beginning of the period	$ 8,907
Balance at beginning of the period	3,360
Balance at end of the period	8,800
Balance at end of the period	4,002
Other Current Liabilities
Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward]
Balance at beginning of the period	8,907	$ 11,164
Warranty provision for sales	3,218	2,116
Settlement of warranty claims	(3,304)	(4,965)
Foreign currency translation and other	(21)	431
Balance at end of the period	8,800	8,746
Other Noncurrent Liabilities
Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward]
Balance at beginning of the period	3,360	6,110
Warranty provision for sales	954	270
Settlement of warranty claims	(241)	(2,594)
Foreign currency translation and other	(71)	4
Balance at end of the period	$ 4,002	$ 3,790