Product Warranties (Details) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2021	Mar. 31, 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	6,714
Balance at end of the period	1,989
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	2,188	1,892
Settlement of warranty claims	(1,699)	(2,567)
Amounts related to sale of the Memcor product line	0	(795)
Foreign currency translation and other	110	65
Balance at end of the period	6,714	5,107
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	714	62
Settlement of warranty claims	(471)	(1,248)
Amounts related to sale of the Memcor product line	0	(135)
Foreign currency translation and other	22	(120)
Balance at end of the period	$ 1,989	$ 1,161