Related Party Transactions (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2024	Jul. 02, 2023	Jun. 30, 2024	Jul. 02, 2023	Oct. 01, 2023
Related Party Transaction [Line Items]
Revenue	$ 1,344,323	$ 1,208,947	$ 3,824,205	$ 3,261,938
Reimbursable costs	15,287	20,848	46,025	61,475
Accounts receivable, net	1,053,758		1,053,758		$ 974,535
Contract assets	118,556		118,556		113,939
Contract liabilities	(372,283)		(372,283)		(335,044)
Related Party
Related Party Transaction [Line Items]
Revenue	16,753	$ 22,373	50,157	$ 65,249
Accounts receivable, net	14,305		14,305		19,944
Contract assets	1,997		1,997		2,723
Contract liabilities	$ (3,708)		$ (3,708)		$ (3,158)