Fair Value Measurements (Details) - USD ($)	12 Months Ended
	Dec. 30, 2018	Dec. 31, 2017	Dec. 25, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred Compensation Plan Assets	$ 38,100,000	$ 40,300,000
Fair value, short-term AFS securities	371,301,000	308,589,000
Fair value, long-term AFS securities	213,558,000	241,411,000
Carrying value of long-term debt	247,000,000	243,000,000
Fair value of long-term debt	260,000,000	279,000,000
Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment charge	0	0	$ 0
Level 1 [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred compensation	23,211,000	29,526,000
Level 2 [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred compensation	0	0
Level 3 [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred compensation	0	0
Estimate of Fair Value Measurement [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred compensation	23,211,000	29,526,000
Debt Securities | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	371,301,000	308,589,000
Fair value, long-term AFS securities	213,558,000	241,411,000
Debt Securities | Level 1 [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	0	0
Fair value, long-term AFS securities	0	0
Debt Securities | Level 2 [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	371,301,000	308,589,000
Fair value, long-term AFS securities	213,558,000	241,411,000
Debt Securities | Level 3 [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	0	0
Fair value, long-term AFS securities	0	0
Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	8,177,000	32,591,000
Commercial Paper [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	8,177,000	32,591,000
Commercial Paper [Member] | Level 1 [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	0	0
Commercial Paper [Member] | Level 2 [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	8,177,000	32,591,000
Commercial Paper [Member] | Level 3 [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	0	0
Certificates of Deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	23,497,000	9,300,000
Certificates of Deposit [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	23,497,000	9,300,000
Certificates of Deposit [Member] | Level 1 [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	0	0
Certificates of Deposit [Member] | Level 2 [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	23,497,000	9,300,000
Certificates of Deposit [Member] | Level 3 [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	0	0
US Government Agencies Debt Securities | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	91,974,000	45,640,000
Fair value, long-term AFS securities	37,197,000	96,779,000
US Government Agencies Debt Securities | Level 1 [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	0	0
Fair value, long-term AFS securities	0	0
US Government Agencies Debt Securities | Level 2 [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	91,974,000	45,640,000
Fair value, long-term AFS securities	37,197,000	96,779,000
US Government Agencies Debt Securities | Level 3 [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	0	0
Fair value, long-term AFS securities	0	0
US Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	107,485,000	70,951,000
Fair value, long-term AFS securities	46,737,000	52,628,000
US Treasury Securities [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	107,485,000	70,951,000
Fair value, long-term AFS securities	46,737,000	52,628,000
US Treasury Securities [Member] | Level 1 [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	0	0
Fair value, long-term AFS securities	0	0
US Treasury Securities [Member] | Level 2 [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	107,485,000	70,951,000
Fair value, long-term AFS securities	46,737,000	52,628,000
US Treasury Securities [Member] | Level 3 [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	0	0
Fair value, long-term AFS securities	0	0
Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	140,168,000	150,107,000
Fair value, long-term AFS securities	129,624,000	92,004,000
Corporate Debt Securities [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	140,168,000	150,107,000
Fair value, long-term AFS securities	129,624,000	92,004,000
Corporate Debt Securities [Member] | Level 1 [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	0	0
Fair value, long-term AFS securities	0	0
Corporate Debt Securities [Member] | Level 2 [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	140,168,000	150,107,000
Fair value, long-term AFS securities	129,624,000	92,004,000
Corporate Debt Securities [Member] | Level 3 [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, short-term AFS securities	0	0
Fair value, long-term AFS securities	$ 0	$ 0