Acquisitions - Narrative (Details) £ / shares in Units, $ in Thousands, £ in Millions			3 Months Ended			9 Months Ended		12 Months Ended
	Jan. 23, 2023 USD ($) employee	Jan. 23, 2023 GBP (£) employee	Jun. 30, 2024 USD ($)	Mar. 31, 2024 USD ($)	Jul. 02, 2023 USD ($)	Jun. 30, 2024 USD ($)	Jul. 02, 2023 USD ($)	Oct. 01, 2023 USD ($) employee program	Oct. 02, 2022 USD ($)	Sep. 23, 2022 £ / shares
Business Acquisition [Line Items]
Goodwill			$ 1,992,110			$ 1,992,110		$ 1,880,244
Acquisition and integration expenses			0		$ 2,107	0	$ 25,812
Reduction in contingent earn-out liabilities			$ 0			$ 0	8,500
Minimum
Business Acquisition [Line Items]
Significant unobservable input, earn-out period						3 years
Minimum | Existing customer contracts
Business Acquisition [Line Items]
Useful life of intangible assets			1 year			1 year
Maximum
Business Acquisition [Line Items]
Significant unobservable input, earn-out period						5 years
Maximum | Existing customer contracts
Business Acquisition [Line Items]
Useful life of intangible assets			12 years			12 years
LS Technologies
Business Acquisition [Line Items]
Total purchase price				$ 120,000
Initial cash payments				93,000
Cash holdback related to tax reserve				4,000
Intangible assets				23,000
Equity interests issued and issuable				23,000
Net tangible assets				12,000
Goodwill				85,000
LS Technologies | Maximum
Business Acquisition [Line Items]
Equity interests issued and issuable				$ 60,000
RPS Group PLC
Business Acquisition [Line Items]
Total purchase price	$ 784,000	£ 633
Intangible assets	174,094
Goodwill	$ 652,762
Pence per share expected to be acquired | £ / shares										£ 2.22
Number of employees | employee	5,000	5,000
Acquisition and integration expenses					$ 2,100		$ 25,800
Net purchase price	$ 675,000
RPS Group PLC | Foreign Exchange Forward
Business Acquisition [Line Items]
Foreign currency forward contract, asset fair value	$ 109,300								$ 19,900
Amyx, Inc.
Business Acquisition [Line Items]
Total purchase price								$ 120,900
Number of employees | employee								500
Number of government programs acquired | program								30
Payables related to promissory note								$ 100,000
Receivables (payables) related to estimated post-closing adjustments								8,700
Contingent earn-out liability								12,200
Aggregate maximum of contingent consideration								$ 25,000