Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Thousands | Sep. 26, 2021 | Dec. 27, 2020 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | $ 357,814 | $ 309,080 |
Long-term AFS securities | 360,721 | 286,831 |
Level 1 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Deferred compensation | 19,998 | 22,245 |
Contingent consideration | 0 | 0 |
Level 2 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Deferred compensation | 0 | 0 |
Contingent consideration | 0 | 0 |
Level 3 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Deferred compensation | 0 | 0 |
Contingent consideration | 7,450 | 8,431 |
Fair Value | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Deferred compensation | 19,998 | 22,245 |
Contingent consideration | 7,450 | 8,431 |
Debt Securities | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 357,814 | 309,080 |
Long-term AFS securities | 360,721 | 286,831 |
Debt Securities | Level 1 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 0 | 0 |
Long-term AFS securities | 0 | 0 |
Debt Securities | Level 2 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 357,814 | 309,080 |
Long-term AFS securities | 360,721 | 286,831 |
Debt Securities | Level 3 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 0 | 0 |
Long-term AFS securities | 0 | 0 |
U.S. Treasury securities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 109,592 | 79,503 |
Long-term AFS securities | 71,861 | 97,565 |
U.S. Treasury securities | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 109,592 | 79,503 |
Long-term AFS securities | 71,861 | 97,565 |
U.S. Treasury securities | Level 1 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 0 | 0 |
Long-term AFS securities | 0 | 0 |
U.S. Treasury securities | Level 2 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 109,592 | 79,503 |
Long-term AFS securities | 71,861 | 97,565 |
U.S. Treasury securities | Level 3 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 0 | 0 |
Long-term AFS securities | 0 | 0 |
Certificates of deposit | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 109,253 | 36,525 |
Certificates of deposit | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 109,253 | 36,525 |
Certificates of deposit | Level 1 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 0 | 0 |
Certificates of deposit | Level 2 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 109,253 | 36,525 |
Certificates of deposit | Level 3 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 0 | 0 |
Corporate debt securities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 100,974 | 130,301 |
Long-term AFS securities | 234,291 | 135,934 |
Corporate debt securities | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 100,974 | 130,301 |
Long-term AFS securities | 234,291 | 135,934 |
Corporate debt securities | Level 1 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 0 | 0 |
Long-term AFS securities | 0 | 0 |
Corporate debt securities | Level 2 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 100,974 | 130,301 |
Long-term AFS securities | 234,291 | 135,934 |
Corporate debt securities | Level 3 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 0 | 0 |
Long-term AFS securities | 0 | 0 |
U.S. governmental agency securities | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 19,974 | 25,171 |
Long-term AFS securities | 42,454 | 48,348 |
U.S. governmental agency securities | Level 1 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 0 | 0 |
Long-term AFS securities | 0 | 0 |
U.S. governmental agency securities | Level 2 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 19,974 | 25,171 |
Long-term AFS securities | 42,454 | 48,348 |
U.S. governmental agency securities | Level 3 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 0 | 0 |
Long-term AFS securities | 0 | 0 |
Commercial paper | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 18,021 | 37,580 |
Commercial paper | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 18,021 | 37,580 |
Commercial paper | Level 1 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 0 | 0 |
Commercial paper | Level 2 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 18,021 | 37,580 |
Commercial paper | Level 3 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 0 | 0 |
Municipal securities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Long-term AFS securities | 12,115 | 4,984 |
Municipal securities | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Long-term AFS securities | 12,115 | 4,984 |
Municipal securities | Level 1 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Long-term AFS securities | 0 | 0 |
Municipal securities | Level 2 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Long-term AFS securities | 12,115 | 4,984 |
Municipal securities | Level 3 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Long-term AFS securities | 0 | 0 |
Life insurance | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Miscellaneous assets | $ 51,200 | $ 49,200 |