Nature of Operations and Summary of Significant Accounting Policies - Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Thousands	Sep. 29, 2018	Dec. 30, 2017	Sep. 30, 2017	Dec. 31, 2016
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 57,384	$ 75,425	$ 90,622	$ 71,487
Restricted cash	675	1,421	766	2,082
Total Cash, Cash Equivalents, and Restricted Cash	$ 58,059	$ 76,846	$ 91,388	$ 73,569