Product Warranties (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward]
Balance at beginning of the period	$ 4,922
Balance at beginning of the period	2,332
Balance at end of the period	5,131
Balance at end of the period	1,471
Other Current Liabilities
Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward]
Balance at beginning of the period	4,922	$ 8,907
Warranty provision for sales	1,251	1,373
Settlement of warranty claims	(1,989)	(1,428)
Amounts related to sale of the Memcor product line	795	0
Foreign currency translation and other	152	124
Balance at end of the period	5,131	8,976
Other Noncurrent Liabilities
Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward]
Balance at beginning of the period	2,332	3,360
Warranty provision for sales	44	300
Settlement of warranty claims	(1,076)	0
Amounts related to sale of the Memcor product line	135	0
Foreign currency translation and other	36	(4)
Balance at end of the period	$ 1,471	$ 3,656