Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2024	Sep. 30, 2023
Assets, Current [Abstract]
Cash and cash equivalents	$ 310,929	$ 678,910
Short-term marketable securities	151,162	338,873
Accounts receivable, net of allowance for expected credit losses ($6,558 and $8,057, respectively)	172,711	156,535
Inventories	115,256	128,198
Derivative asset	0	13,036
Short-term restricted cash included in prepaid expenses and other current assets	2,069	4,650
Prepaid expenses and other current assets	80,680	98,754
Total current assets	832,807	1,418,956
Property, plant and equipment, net	202,654	205,744
Long-term marketable securities	49,454	111,338
Long-term deferred tax assets	837	571
Operating lease right-of-use assets	63,992	66,580
Goodwill	691,409	784,339
Intangibles assets, net	248,030	294,301
Other assets	10,858	3,891
Total assets	2,100,041	2,885,720
Liabilities, Current [Abstract]
Accounts payable	44,433	35,796
Deferred revenue	31,978	34,614
Accrued warranty and retrofit costs	10,129	10,223
Accrued compensation and benefits	30,713	33,911
Accrued customer deposits	22,324	17,707
Accrued VAT payable	106	20,595
Accrued income taxes payable	13,278	7,378
Accrued Expenses and Other Current Liabilities	51,878	50,704
Total current liabilities	204,839	210,928
Long-term tax reserves	398	380
Long-term deferred tax liabilities	54,177	67,301
Long-term operating lease liabilities	58,792	60,436
Other Liabilities, Noncurrent	12,868	12,175
Total liabilities	331,074	351,220
Stockholders' equity
Preferred stock, $0.01 par value - 1,000,000 shares authorized, no shares issued or outstanding	0	0
Common stock, $0.01 par value - 125,000,000 shares authorized, 59,031,953 shares issued and 45,570,084 shares outstanding at September 30, 2024, 71,294,247 shares issued and 57,832,378 shares outstanding at September 30, 2023	590	713
Additional paid-in capital	505,958	1,156,160
Accumulated other comprehensive loss	(13,464)	(62,426)
Treasury stock, at cost - 13,461,869 shares at September 30, 2024 and September 30, 2023	(200,956)	(200,956)
Retained earnings	1,476,839	1,641,009
Total stockholders' equity	1,768,967	2,534,500
Total liabilities and stockholders' equity	$ 2,100,041	$ 2,885,720