v3.26.1
PA Consulting Redeemable Noncontrolling Interests - Narrative (Details)
$ / shares in Units, $ in Thousands, £ in Millions
3 Months Ended 6 Months Ended 53 Months Ended
Mar. 20, 2026
USD ($)
Jan. 02, 2026
GBP (£)
shares
Mar. 27, 2026
USD ($)
$ / shares
shares
Mar. 28, 2025
USD ($)
Mar. 27, 2026
USD ($)
$ / shares
shares
Mar. 28, 2025
USD ($)
$ / shares
Jul. 31, 2025
Jan. 02, 2026
$ / shares
shares
Sep. 26, 2025
USD ($)
$ / shares
shares
Sep. 27, 2024
$ / shares
Business Combination [Line Items]                    
Common stock, par value (in dollars per share) | $ / shares     $ 1   $ 1       $ 1 $ 1.00
Common stock, issued (in shares) | shares     118,190,953   118,190,953       119,081,294  
Redemption of redeemable noncontrolling interests relating to the PA Consulting Transaction     $ (36,011)   $ (36,011)          
Redemption of redeemable noncontrolling interests relating to the PA Consulting Transaction         $ (883,623) $ (4,066)        
Preference share effect on basic earnings per share (in dollars per share) | $ / shares         $ 0.11 $ 0.05        
Allocated share-based compensation expense       $ 8,000   $ 13,900        
Equity-Based Incentive Grants                    
Business Combination [Line Items]                    
Accrued cumulative expense associated with the vested grants                 $ 103,800  
Allocated share-based compensation expense     214,900   $ 237,500 13,900        
Equity-Based Incentive Grants | Share-Based Payment Arrangement, Tranche One                    
Business Combination [Line Items]                    
Award vesting percentage             40.00%      
Equity-Based Incentive Grants | Share-Based Payment Arrangement, Tranche Two                    
Business Combination [Line Items]                    
Award vesting percentage 60.00%                  
PA Consulting                    
Business Combination [Line Items]                    
Redemption of redeemable noncontrolling interests relating to the PA Consulting Transaction         (400) $ (4,100)        
PA Consulting Employees                    
Business Combination [Line Items]                    
Redemption of redeemable noncontrolling interests relating to the PA Consulting Transaction         (1,119,417)          
Ownership interest of employees (as a percent)                 71.00%  
Retained Earnings                    
Business Combination [Line Items]                    
Redemption of redeemable noncontrolling interests relating to the PA Consulting Transaction     $ (36,011)   (36,011)          
PA Consulting Group Limited                    
Business Combination [Line Items]                    
Consideration transferred | £   £ 1,210.0                
Consideration paid in cash   £ 997.6     $ 123,900          
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                
Common stock, issued (in shares) | shares     2,043,537   2,043,537     2,043,537    
Initial consideration distributed in cash $ 113,500                  
Business combination, additional deferred consideration payable to acquiree employees     $ 10,400   $ 10,400          
Cash in employee benefit trust     $ 116,500   $ 116,500       $ 1,400