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