PA Consulting Business Combination - Schedule of Change in Redeemable Noncontrolling Interest (Details) - USD ($) $ in Thousands	12 Months Ended
Sep. 29, 2023	Sep. 30, 2022	Oct. 01, 2021
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Redeemable noncontrolling interest, beginning balance	$ 44,336
Attribution of Preferred Dividend to Common Shareholders	(22,739)	$ (27,248)	$ (44,372)
Redeemable noncontrolling interest, ending balance	53,862	44,336
PA Consulting Employees
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Redeemable noncontrolling interest, beginning balance	632,522	657,722
Accrued Preferred Dividend to Preference Shareholders	72,891	67,598
Attribution of Preferred Dividend to Common Shareholders	(72,891)	(67,598)
Net earnings attributable to redeemable noncontrolling interest to Common Shareholders	21,614	34,585
Redeemable Noncontrolling interests redemption value adjustment	10,770	27,657
Repurchase of redeemable noncontrolling interests	(111,005)	(53,834)
Issuance of redeemable noncontrolling interests	37,789	54,884
Cumulative translation adjustment and other	41,289	(88,492)
Redeemable noncontrolling interest, ending balance	$ 632,979	$ 632,522	$ 657,722

Amount of equity (deficit) attributable to noncontrolling interest. Excludes temporary equity.

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Decrease in noncontrolling interest balance from payment of dividends or other distributions by the non-wholly owned subsidiary or partially owned entity, included in the consolidation of the parent entity, to the noncontrolling interest holders.

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Net Increase or Decrease in balance of noncontrolling interest in the subsidiary during the reporting period.

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Amount of Net Income (Loss) attributable to redeemable noncontrolling interest.

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Amount before tax, after reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature, attributable to noncontrolling interests.

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