Cash and Receivables Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Jan. 01, 2017	Jan. 03, 2016
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning Balance, Current	$ 4,030	$ 3,488	$ 2,343
Beginning Balance, Noncurrent	26	257	246
Provision for Doubtful Accounts, Franchisees and other	579	390	979
Uncollectible accounts written-off, net of recoveries	(89)	(79)
Uncollectible accounts written off, net of recoveries			177
Ending Balance, Current	4,546	4,030	3,488
Ending Balance, Noncurrent	0	26	257
Allowances for Doubtful Accounts Receivable, Balance	$ 4,546	$ 4,056	$ 3,745