Quarterly report pursuant to Section 13 or 15(d)

Sales to Major Customers (Details)

v3.8.0.1
Sales to Major Customers (Details)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2017
USD ($)
Oct. 01, 2016
Sep. 30, 2017
USD ($)
customer
Oct. 01, 2016
customer
Segment Reporting, Asset Reconciling Item        
Number of major customers | customer     2 2
Sales Revenue, Net | Customer Concentration Risk | Major Customer One        
Segment Reporting, Asset Reconciling Item        
Percent of consolidated revenue 20.00% 21.00% 20.00% 21.00%
Sales Revenue, Net | Customer Concentration Risk | Major Customer Two        
Segment Reporting, Asset Reconciling Item        
Percent of consolidated revenue 17.00% 15.00% 17.00% 15.00%
Sales Revenue, Net | Customer Concentration Risk | Two Major Customers        
Segment Reporting, Asset Reconciling Item        
Accounts receivable from major customers | $ $ 29.9   $ 29.9