Equity Agreements and Incentive Equity Plans (Details)	3 Months Ended	6 Months Ended
	Jun. 25, 2021 $ / shares shares	Jun. 25, 2021 $ / shares shares
B-1 Incentive Units
Incentive Unit Activity [Roll Forward]
Outstanding units, beginning balance (in shares) | shares		70,739,000
Units granted (in shares) | shares	0	1,200,000
Units forfeited (in shares) | shares		3,353,000
Outstanding units, ending balance (in shares) | shares	68,586,000	68,586,000
Vested units (in shares) | shares	34,916,000	34,916,000
Nonvested units (in shares) | shares	33,670,000	33,670,000
Weighted- Average Grant-Date Fair Value
Outstanding units, beginning balance (in dollars per shares) | $ / shares		$ 0.34
Units granted (in dollars per share) | $ / shares		0.51
Units forfeited (in dollars per share) | $ / shares		0.39
Outstanding units, ending balance (in dollars per shares) | $ / shares	$ 0.34	0.34
Weighted- Average Grant-Date Fair Value
Units vested (in dollars per share) | $ / shares		0.31
Units nonvested (in dollars per share) | $ / shares	$ 0.37	$ 0.37
B-2 Incentive Units
Incentive Unit Activity [Roll Forward]
Outstanding units, beginning balance (in shares) | shares		19,822,000
Units granted (in shares) | shares		0
Units forfeited (in shares) | shares		0
Outstanding units, ending balance (in shares) | shares	19,822,000	19,822,000
Vested units (in shares) | shares	0	0
Nonvested units (in shares) | shares	19,822,000	19,822,000
Weighted- Average Grant-Date Fair Value
Outstanding units, beginning balance (in dollars per shares) | $ / shares		$ 0.06
Units granted (in dollars per share) | $ / shares		0
Units forfeited (in dollars per share) | $ / shares		0
Outstanding units, ending balance (in dollars per shares) | $ / shares	$ 0.06	0.06
Weighted- Average Grant-Date Fair Value
Units vested (in dollars per share) | $ / shares		0
Units nonvested (in dollars per share) | $ / shares	$ 0.06	$ 0.06