Transactions with Related Parties Other Related Party Transactions (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	Jul. 17, 2015	Dec. 31, 2017	May 29, 2015	Jan. 01, 2012
Related Party Transaction
Percentage of Outstanding Shares Owned by the Trian Group			24.80%
Purchase agreement
Related Party Transaction
Treasury Stock, Shares, Acquired	18,416
Treasury Stock Acquired, Average Cost Per Share	$ 11.45
Treasury Stock, Value, Acquired, Cost Method, excluding Commissions	$ 210,867
Arby's Restaurant Group, Inc
Related Party Transaction
Proceeds from Divestiture of Business, Percentage of Buyer Stock Received		18.50%		18.50%