Product Warranties (Details) - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
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	8,063
Balance at end of the period	2,629
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	5,680	2,496
Settlement of warranty claims	(3,826)	(3,243)
Amounts related to sale of the Memcor product line	0	(795)
Foreign currency translation and other	94	276
Balance at end of the period	8,063	5,246
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	1,577	481
Settlement of warranty claims	(701)	(1,298)
Amounts related to sale of the Memcor product line	0	(136)
Foreign currency translation and other	29	(51)
Balance at end of the period	$ 2,629	$ 1,600