Product Warranties (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward]
Balance at beginning of the period	$ 6,115
Balance at beginning of the period	1,724
Balance at end of the period	5,577
Balance at end of the period	1,646
Other Current Liabilities
Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward]
Balance at beginning of the period	6,115	$ 4,922
Warranty provision for sales	371	1,251
Settlement of warranty claims	(978)	(1,989)
Amounts related to sale of the Memcor product line	0	(795)
Foreign currency translation and other	69	152
Balance at end of the period	5,577	5,131
Other Noncurrent Liabilities
Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward]
Balance at beginning of the period	1,724	2,332
Warranty provision for sales	252	44
Settlement of warranty claims	(374)	(1,076)
Amounts related to sale of the Memcor product line	0	(135)
Foreign currency translation and other	44	36
Balance at end of the period	$ 1,646	$ 1,471