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Long Term Debt (Details) - USD ($)
 12 Months Ended
Sep. 28, 2017
Dec. 31, 2017
Dec. 31, 2016
Disclosure of detailed information about borrowings [line items]      
Non-Current   $ 0 $ 36,200,000
Repayment of credit facility $ 36,200,000 36,200,000 0
Credit Facility [member]      
Disclosure of detailed information about borrowings [line items]      
Non-Current   $ 0 $ 36,200,000