Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Mar. 31, 2026	Dec. 31, 2025	Mar. 31, 2025	Mar. 31, 2026	Mar. 31, 2025	Sep. 30, 2025
Income Tax Disclosure [Line Items]
Provision (benefit) for income taxes	$ 156,076		$ 42,605	$ 192,533	$ 53,527
Unrecognized tax benefits	50,500			50,500		$ 157,700
Income taxes payable	161,300			161,300		179,100
Gain on sale of business				464,602	0
Accrued income taxes	118,300			118,300		28,700
Income tax provision upon recognition of unrecognized tax benefit	50,500			50,500
Unrecognized tax benefits, increase in valuation allowance upon recognition	5,600			5,600
Potential decrease in unrecognized tax benefits	1,000			1,000
Other Liabilities [Member]
Income Tax Disclosure [Line Items]
Accrued income taxes	43,000			43,000		$ 150,400
IRS [Member]
Income Tax Disclosure [Line Items]
Provision (benefit) for income taxes		$ (7,100)		(7,100)
Foreign Tax Jurisdiction [Member]
Income Tax Disclosure [Line Items]
Provision (benefit) for income taxes					$ (10,400)
Kepware and ThingWorx
Income Tax Disclosure [Line Items]
Provision (benefit) for income taxes	102,400			102,400
Gain on sale of business	$ 462,600			$ 462,600