Related Party Transactions - Founder and Chairman and PJMF (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 25, 2016	Dec. 27, 2015
Transactions with entity owned by Founder and Chairman
Related party transactions
Cash paid for charter aircraft services	$ 446,000	$ 732,000	$ 653,000
PJMF
Related party transactions
Loyalty program reimbursement received	1,600,000	1,100,000	841,000
Other reimbursements received	$ 1,300,000	$ 1,400,000	$ 1,400,000