SIGNIFICANT ACCOUNTING POLICIES - Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 24, 2017	Dec. 25, 2016
Reconciliation of cash, cash equivalents and restricted cash as reported in the condensed consolidated balance sheets to the total of the same such amounts shown above:
Cash equivalents	$ 4,492	$ 99,387
Restricted cash included in other assets	31,937	31,967
Cash, cash equivalents and restricted cash	$ 36,429	$ 131,354	$ 117,017	$ 36,248