Fair Value Measurements (Details) - USD ($) $ in Thousands | Sep. 24, 2017 | Dec. 25, 2016 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | $ 336,442 | |
Long-term AFS securities | 241,782 | |
Carrying value of long-term debt | 242,577 | $ 240,199 |
Long-term debt, fair value | 281,000 | 298,000 |
Level 1 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Deferred compensation | 28,354 | 31,006 |
Level 2 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Deferred compensation | 0 | 0 |
Level 3 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Deferred compensation | 0 | 0 |
Fair Value | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Deferred compensation | 28,354 | 31,006 |
Debt Securities | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 336,442 | 0 |
Long-term AFS securities | 241,782 | 0 |
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 | 336,442 | 0 |
Long-term AFS securities | 241,782 | 0 |
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 | 73,175 | |
Long-term AFS securities | 47,620 | |
U.S Treasury securities | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 73,175 | 0 |
Long-term AFS securities | 47,620 | 0 |
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 | 73,175 | 0 |
Long-term AFS securities | 47,620 | 0 |
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 |
Corporate debt securities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 156,639 | |
Long-term AFS securities | 97,345 | |
Corporate debt securities | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 156,639 | 0 |
Long-term AFS securities | 97,345 | 0 |
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 | 156,639 | 0 |
Long-term AFS securities | 97,345 | 0 |
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 | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 53,754 | |
Long-term AFS securities | 96,817 | |
U.S. governmental agency securities | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 53,754 | 0 |
Long-term AFS securities | 96,817 | 0 |
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 | 53,754 | 0 |
Long-term AFS securities | 96,817 | 0 |
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 |
Certificates of deposit | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 20,403 | |
Certificates of deposit | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 20,403 | 0 |
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 | 20,403 | 0 |
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 |
Commercial paper | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 32,471 | |
Commercial paper | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | 32,471 | 0 |
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 | 32,471 | 0 |
Commercial paper | Level 3 | Recurring | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Short-term AFS securities | $ 0 | $ 0 |