v3.26.1
FAIR VALUE - Asset Measured at Fair Value (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Mar. 28, 2026
Jun. 27, 2026
Dec. 27, 2025
FAIR VALUE      
Impairment of investments   $ 4,000  
Money market funds | Location, Statement of Financial Position, Balance [Axis]: us-gaap:CashAndCashEquivalentsAtCarryingValue      
FAIR VALUE      
Investments at fair value   88,100 $ 207,900
Money market funds | Location, Statement of Financial Position, Balance [Axis]: us-gaap:RestrictedInvestmentsNoncurrent      
FAIR VALUE      
Investments at fair value   800 600
Fixed income funds | Location, Statement of Financial Position, Balance [Axis]: us-gaap:RestrictedInvestmentsNoncurrent      
FAIR VALUE      
Investments at fair value   51,000 49,900
Equity securities      
FAIR VALUE      
Impairment of investments $ 4,000    
Equity securities | Location, Statement of Financial Position, Balance [Axis]: us-gaap:OtherAssetsNoncurrent      
FAIR VALUE      
Investments at fair value   25,700 28,000
Mutual funds, equity and alternative investments | Location, Statement of Financial Position, Balance [Axis]: us-gaap:MarketableSecuritiesCurrent      
FAIR VALUE      
Investments at fair value   46,300 34,300
Money market and mutual funds | Location, Statement of Financial Position, Balance [Axis]: us-gaap:OtherAssetsNoncurrent      
FAIR VALUE      
Investments at fair value   100 200
Prices with Unobservable Inputs (Level 3)      
FAIR VALUE      
Investments at fair value   25,700  
Prices with Unobservable Inputs (Level 3) | Equity securities      
FAIR VALUE      
Investments at fair value     28,000
Ardellis Insurance Ltd.      
FAIR VALUE      
Total fair value   96,403 84,271
Estimate of Fair Value Measurement | Recurring      
FAIR VALUE      
Investments at fair value   211,155 320,875
Estimate of Fair Value Measurement | Recurring | Money market funds      
FAIR VALUE      
Investments at fair value   88,909 208,501
Estimate of Fair Value Measurement | Recurring | Fixed income funds      
FAIR VALUE      
Investments at fair value   56,878 49,592
Estimate of Fair Value Measurement | Recurring | Treasury securities      
FAIR VALUE      
Investments at fair value   345 345
Estimate of Fair Value Measurement | Recurring | Equity securities      
FAIR VALUE      
Investments at fair value   47,823 46,492
Estimate of Fair Value Measurement | Recurring | Alternative investments      
FAIR VALUE      
Investments at fair value   4,366 4,186
Estimate of Fair Value Measurement | Recurring | Mutual funds      
FAIR VALUE      
Investments at fair value   12,834 11,759
Estimate of Fair Value Measurement | Recurring | Domestic stock funds      
FAIR VALUE      
Investments at fair value   11,367 10,436
Estimate of Fair Value Measurement | Recurring | International stock funds      
FAIR VALUE      
Investments at fair value   943 816
Estimate of Fair Value Measurement | Recurring | Target funds      
FAIR VALUE      
Investments at fair value   12 11
Estimate of Fair Value Measurement | Recurring | Bond funds      
FAIR VALUE      
Investments at fair value   6 6
Estimate of Fair Value Measurement | Recurring | Alternative funds      
FAIR VALUE      
Investments at fair value   506 490
Estimate of Fair Value Measurement | Recurring | Quoted Prices in Active Markets (Level 1)      
FAIR VALUE      
Investments at fair value   111,873 218,012
Estimate of Fair Value Measurement | Recurring | Quoted Prices in Active Markets (Level 1) | Money market funds      
FAIR VALUE      
Investments at fair value   71,769 182,051
Estimate of Fair Value Measurement | Recurring | Quoted Prices in Active Markets (Level 1) | Fixed income funds      
FAIR VALUE      
Investments at fair value   4,836 5,365
Estimate of Fair Value Measurement | Recurring | Quoted Prices in Active Markets (Level 1) | Treasury securities      
FAIR VALUE      
Investments at fair value   345 345
Estimate of Fair Value Measurement | Recurring | Quoted Prices in Active Markets (Level 1) | Equity securities      
FAIR VALUE      
Investments at fair value   22,089 18,492
Estimate of Fair Value Measurement | Recurring | Quoted Prices in Active Markets (Level 1) | Mutual funds      
FAIR VALUE      
Investments at fair value   12,834 11,759
Estimate of Fair Value Measurement | Recurring | Quoted Prices in Active Markets (Level 1) | Domestic stock funds      
FAIR VALUE      
Investments at fair value   11,367 10,436
Estimate of Fair Value Measurement | Recurring | Quoted Prices in Active Markets (Level 1) | International stock funds      
FAIR VALUE      
Investments at fair value   943 816
Estimate of Fair Value Measurement | Recurring | Quoted Prices in Active Markets (Level 1) | Target funds      
FAIR VALUE      
Investments at fair value   12 11
Estimate of Fair Value Measurement | Recurring | Quoted Prices in Active Markets (Level 1) | Bond funds      
FAIR VALUE      
Investments at fair value   6 6
Estimate of Fair Value Measurement | Recurring | Quoted Prices in Active Markets (Level 1) | Alternative funds      
FAIR VALUE      
Investments at fair value   506 490
Estimate of Fair Value Measurement | Recurring | Prices with Other Observable Inputs (Level 2)      
FAIR VALUE      
Investments at fair value   69,182 70,677
Estimate of Fair Value Measurement | Recurring | Prices with Other Observable Inputs (Level 2) | Money market funds      
FAIR VALUE      
Investments at fair value   17,140 26,450
Estimate of Fair Value Measurement | Recurring | Prices with Other Observable Inputs (Level 2) | Fixed income funds      
FAIR VALUE      
Investments at fair value   52,042 44,227
Estimate of Fair Value Measurement | Recurring | Prices with Unobservable Inputs (Level 3)      
FAIR VALUE      
Investments at fair value   30,100 32,186
Estimate of Fair Value Measurement | Recurring | Prices with Unobservable Inputs (Level 3) | Equity securities      
FAIR VALUE      
Investments at fair value   25,734 28,000
Estimate of Fair Value Measurement | Recurring | Prices with Unobservable Inputs (Level 3) | Alternative investments      
FAIR VALUE      
Investments at fair value   $ 4,366 $ 4,186