Discontinued Operations - Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Disposal Group, Including Discontinued Operation, Assets, Current [Abstract]
Cash and cash equivalents	$ 45,000	$ 45,000	$ 45,000
Total current assets of discontinued operation	311,385	222,863
Disposal Group, Including Discontinued Operation, Assets, Noncurrent [Abstract]
Total long-term assets of discontinued operation	183,828	98,718
Disposal Group, Including Discontinued Operation, Liabilities, Current [Abstract]
Total current liabilities of discontinued operation	128,939	82,832
Disposal Group, Including Discontinued Operation, Liabilities, Noncurrent [Abstract]
Total long-term liabilities of discontinued operation	32,444	27,575
Discontinued Operations, Held-for-sale | Semiconductor Automation Business
Disposal Group, Including Discontinued Operation, Assets, Current [Abstract]
Cash and cash equivalents	45,000	45,000
Accounts receivable, net	142,256	93,498
Inventories	110,735	77,708
Other current assets	13,394	6,657
Total current assets of discontinued operation	311,385	222,863
Disposal Group, Including Discontinued Operation, Assets, Noncurrent [Abstract]
Property, plant and equipment, net	32,058	28,931
Long-term deferred tax assets	3,167	1,143
Goodwill	81,477	48,359
Intangibles, net	44,468	6,002
Other assets	22,658	14,283
Total long-term assets of discontinued operation	183,828	98,718
Disposal Group, Including Discontinued Operation, Liabilities, Current [Abstract]
Accounts payable	68,074	36,070
Deferred revenue	7,141	5,580
Accrued warranty and retrofit costs	6,081	5,990
Accrued compensation and benefits	18,144	14,598
Accrued Income Taxes	11,702	8,118
Accrued expenses and other current liabilities	18,014	12,476
Total current liabilities of discontinued operation	129,156	82,832
Disposal Group, Including Discontinued Operation, Liabilities, Noncurrent [Abstract]
Long-term tax reserves	2,356	697
Long-term deferred tax liabilities	6,548	141
Long-term pension liabilities	5,490	5,511
Long-term operating lease liabilities	15,425	12,950
Other long-term liabilities	2,625	8,276
Total long-term liabilities of discontinued operation	$ 32,444	$ 27,575