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Basis of Presentation (Details) £ in Millions	Jan. 02, 2026 GBP (£) shares	Sep. 27, 2024 $ / shares shares	Jun. 26, 2026 $ / shares	Jan. 02, 2026 $ / shares	Sep. 26, 2025 $ / shares
Business Combination [Line Items]
Common stock, par value (in dollars per share) \| $ / shares		$ 1.00	$ 1		$ 1
Discontinued Operations, Disposed of by Means Other than Sale, Spinoff \| SpinCo Business
Business Combination [Line Items]
Common stock, par value (in dollars per share) \| $ / shares		$ 0.01
Stock issued during period, spinoff transaction ( in shares) \| shares		124,084,108
Shares issued during period, spinoff, conversion ratio (in shares) \| shares		1
PA Consulting Group Limited
Business Combination [Line Items]
Consideration transferred \| £	£ 1,210.0
Consideration paid in cash \| £	£ 997.6
Business combination share issued (in shares) \| shares	2,043,537
Common stock, par value (in dollars per share) \| $ / shares				$ 1.00
Business combination, additional consideration deferred, estimated equity value \| £	£ 75.0