Segment Information - Narratives (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($)	Jul. 01, 2017 USD ($)	Jun. 30, 2018 USD ($) segment	Jul. 01, 2017 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment			3
Write off of debt issuance cost				$ 6,097
Inventory write-down		$ 23		1
Inventory adjustment	$ 12,191		$ 12,191
Legal fees	10,734	7,766	24,294	15,762
Secondary offering		1,026		1,026
Business acquisition, transaction costs	$ 1,614		4,164
Executive compensation expense			$ 2,401
Consolidating cost		$ 665		811
Business exit costs				643
IPO cost				348
Gain on the settlement of contract				$ 2,247