Revenue from Contracts with Customers (Additional Information) (Details) - USD ($) $ in Thousands	6 Months Ended
	Mar. 28, 2020	Sep. 30, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Contract with Customer, Asset, Reclassified to Receivable	$ 10,200
Contract with Customer, Asset, Additions during Period	8,800
Deferred Revenue, Revenue Recognized	283,400
Deferred Revenue, Additions	301,300
Short Term and Long Term Accounts Receivable	431,000	$ 412,500
Refund Liability	30,200	22,900
Deferred revenue	417,202	396,632
Revenue, Remaining Performance Obligation, Amount	1,026,000
Other Current Assets
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Capitalized Contract Cost, Net	29,700	27,700
Other Assets
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Capitalized Contract Cost, Net	65,700	$ 64,800
Unrecorded [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 608,800