Basis and Summary of Significant Accounting Policies - Accounts Receivable Net of Allowances (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable	$ 92,311	$ 99,887
Customers
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable	54,463	48,661
Corporate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable	15,500	23,431
Franchisee
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable	$ 22,348	$ 27,795