Senior Credit Facility - Credit Agreement (Details) - USD ($) $ in Thousands									3 Months Ended	12 Months Ended
	Dec. 26, 2020	Nov. 04, 2020	Oct. 30, 2020	Apr. 22, 2020	Mar. 12, 2020	Dec. 28, 2019	Jun. 15, 2017	Feb. 19, 2016	Dec. 26, 2020	Dec. 26, 2020
Line of Credit Facility
Senior Credit Facility, Maximum Borrowing Capacity		$ 500,000
Swingline Loan, Maximum Borrowing Capacity		$ 50,000
Debt Issuance Costs, Net	$ (15,700)					$ (1,000)			$ (15,700)	$ (15,700)
Unsecured debt, net of debt issuance costs	984,300					396,500			984,300	984,300
Unsecured Debt, Current	0					(30,000)			0	0
Long-term Debt, Excluding Current Maturities	984,324					366,480			984,324	984,324
Debt Instrument, Maturity Date		Nov. 04, 2020
Unsecured Debt	1,000,000					397,500			1,000,000	1,000,000
Letters of Credit Outstanding, Amount	48,700					32,000			48,700	$ 48,700
Debt Instrument, Basis Spread on Variable Rate										0.125%
Debt Instrument, Covenant Compliance										all
Senior Notes	$ 150,000								$ 150,000	$ 150,000
Senior Notes - Maturity Date	Aug. 14, 2029
Debt Instrument, Basis Spread on Variable Rate LIBOR Plus										1.125%
Debt Instrument, Basis Spread on Variable Rate Revolver										0.125%
Letters of Credit, Maximum Borrowing Capacity		$ 150,000
Base Rate
Line of Credit Facility
Line of Credit Facility, Interest Rate at Period End	3.25%								3.25%	3.25%
London Interbank Offered Rate (LIBOR)
Line of Credit Facility
Line of Credit Facility, Interest Rate at Period End	0.146%								0.146%	0.146%
Minimum
Line of Credit Facility
Debt Instrument, Basis Spread on Variable Rate										0.00%
Commitment fee for unused capacity										0.09%
Debt Instrument, Basis Spread on Variable Rate, Minimum										0.875%
Maximum
Line of Credit Facility
Debt Instrument, Basis Spread on Variable Rate										0.375%
Commitment fee for unused capacity									0.20%
Debt Instrument, Basis Spread on Variable Rate, Maximum										1.375%
2016 Senior Credit Facility
Line of Credit Facility
Debt Instrument, Maturity Date		Nov. 04, 2023
Senior Notes - Maturity Date		Nov. 04, 2024
February 2016 Term Loan
Line of Credit Facility
Debt Instrument, Issuance Date								Feb. 19, 2016
Term loan, Maximum Month End Outstanding Amount	$ 0					145,000			$ 0	$ 0
Term Loan, Maximum Borrowing Capacity								$ 200,000
June 2017 Term Loan
Line of Credit Facility
Debt Instrument, Issuance Date							Jun. 15, 2017
Term loan, Maximum Month End Outstanding Amount	0					87,500			0	0
Term Loan, Maximum Borrowing Capacity							$ 100,000
November 2020 Term Loan
Line of Credit Facility
Debt Instrument, Issuance Date		Nov. 04, 2020
Term loan, Maximum Month End Outstanding Amount	200,000					0			200,000	200,000
Term Loan, Maximum Borrowing Capacity		$ 200,000
Bonds
Line of Credit Facility
Debt Instrument, Issuance Date			Oct. 30, 2020
Senior Notes	650,000					0			650,000	650,000
Notes Payable to Banks
Line of Credit Facility
Senior Notes	150,000					150,000			$ 150,000	$ 150,000
March 2020 Term Loan [Member]
Line of Credit Facility
Debt Instrument, Issuance Date					Mar. 12, 2020
Term Loan, Maximum Borrowing Capacity					$ 200,000
April 2020 Term Loan [Member]
Line of Credit Facility
Debt Instrument, Issuance Date				Apr. 22, 2020
Term Loan, Maximum Borrowing Capacity				$ 350,000
Debt Instrument, Maturity Date			Oct. 30, 2020
2016 Senior Credit Facility
Line of Credit Facility
Line of Credit Facility, Maximum Month-end Outstanding Amount	$ 0					$ 15,000
Number of Financial Covenants
Line of Credit Facility
Debt Instrument, Covenant Description										two
Fixed Charge Coverage Ratio Minimum Requirement
Line of Credit Facility
Debt Instrument, Covenant Description										2.00
Leverage Ratio Maximum Requirement
Line of Credit Facility
Debt Instrument, Covenant Description										4.00