Description of Business (Details) $ / shares in Units, $ in Thousands			1 Months Ended	3 Months Ended		6 Months Ended
	Feb. 10, 2021 shares	Jan. 14, 2021 USD ($) $ / shares shares	Feb. 10, 2021 USD ($)	Jun. 26, 2021 USD ($) franchise_location shares	Jun. 27, 2020 USD ($)	Jun. 26, 2021 USD ($) franchise_location shares	Jun. 27, 2020 USD ($)	Jan. 13, 2021 shares	Dec. 26, 2020 shares
Subsidiary, Sale of Stock [Line Items]
Number of locations franchised, independently-operated, and company-operated | franchise_location				4,300		4,300
Number of states in which entity operates | franchise_location				49		49
Number of countries across Europe in which entity operates | franchise_location				14		14
Percentage of locations franchised or independently operated				0.82		0.82
Repayment of debt | $		$ 725,000
Loss on debt extinguishment | $				$ 78	$ 0	$ 45,576	$ 0
Estimated future payments under the income tax receivable agrement | $				$ 156,000		$ 156,000
Stock split		88,990
Number of authorized shares (in shares)		1,000,000,000						10,000
Number of shares authorized (in shares)		900,000,000		900,000,000		900,000,000			900,000,000
Number of shares of preferred stock authorized (in shares)		100,000,000
Pre-IPO Stockholders
Subsidiary, Sale of Stock [Line Items]
Income taxes receivable (percent)		0.85
IPO
Subsidiary, Sale of Stock [Line Items]
Sale of stock (in shares)		32,000,000
Sale of stock (in dollars per share) | $ / shares		$ 22
Total proceeds received | $			$ 761,000
Number of shares purchased from existing shareholders (in shares)		2,000,000
Over-Allotment Option
Subsidiary, Sale of Stock [Line Items]
Sale of stock (in shares)	5,000,000
Total proceeds received | $		$ 43,000