Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 25, 2016	Dec. 27, 2015
Movement in Valuation Allowances and Reserves
Balance at Beginning of Year	$ 9,707	$ 8,966	$ 9,878
Charged to costs and expenses		658	1,166
Recovered from costs and expenses	(378)
Additions	1,404	83
Deductions			(2,078)
Balance at End of Year	10,733	9,707	8,966
Reserve for uncollectible accounts receivable
Movement in Valuation Allowances and Reserves
Balance at Beginning of Year	1,486	2,447	3,814
Charged to costs and expenses	1,744	659	1,332
Deductions	(959)	(1,620)	(2,699)
Balance at End of Year	2,271	1,486	2,447
Reserve for franchisee notes receivable
Movement in Valuation Allowances and Reserves
Balance at Beginning of Year	2,759	3,653	3,132
Recovered from costs and expenses	(1,715)	(250)	(100)
Additions	3		621
Deductions		(644)
Balance at End of Year	1,047	2,759	3,653
Valuation allowance on deferred tax assets
Movement in Valuation Allowances and Reserves
Balance at Beginning of Year	5,462	2,866	2,932
Charged to costs and expenses		249
Recovered from costs and expenses	(407)		(66)
Additions	2,360	2,347
Balance at End of Year	$ 7,415	$ 5,462	$ 2,866