Basis of Presentation and Summary of Significant Accounting Policies - Customer Bankruptcy & Non-Monetary Transactions (Details) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Jul. 01, 2017	Jan. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017	Dec. 31, 2016
Concentration Risk [Line Items]
Bad debt expense					$ 37	$ 7,805
Release of product return and rebate reserves					12,400
WynitDistribution [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Unrecognized revenue, net				$ 8,100
Allowance for Doubtful Accounts Receivable				35,800
Unrecoverable inventory				5,500
Accounts receivable for shipments made in the quarter				30,300		30,300
Insurance proceeds receivable, accounts receivable				22,700		22,700
Probably insurance proceeds				26,800		26,800
Insurance proceeds receivable, inventory				4,100		4,100
Charges offset by insurance recorded						9,000
Bad debt expense				7,600
Cost of revenue				$ 1,400
Proceeds from insurance settlement		$ 5,400	$ 21,400
WynitDistribution [Member] | Revenue [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	11.00%
WynitDistribution [Member] | Accounts Receivable [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	19.00%
Advertising Barter Transactions [Member]
Concentration Risk [Line Items]
Nonmonetary transaction, gross operating revenue recognized							$ 15,000
Nonmonetary transaction, cost of goods transferred							7,000
Nonmonetary transaction, advertising credit received							13,000
Nonmonetary transaction, cash received							$ 2,000
Nonmonetary transaction, remaining advertising credit			$ 12,200		$ 11,100
Nonmonetary transaction, advertising credit, expected period of use					6 years
Nonmonetary transaction, advertising credit utilized during the period					$ 1,100	$ 300