Concentration Of Credit Risk - (Details)
12 Months Ended
Dec. 31, 2016
USD ($)
Customer
Net Sales | Customer Concentration Risk  
Concentration Risk [Line Items]  
Number of Customers Used For Concentration Risk Disclosure | Customer 10
Concentration risk, percentage 15.20%
Maximum percent of revenue from single customer 3.40%
Payment Guarantee  
Concentration Risk [Line Items]  
Retained recourse obligation $ 5,863,000
Total contracts 30,215,000
Other Long-Term Obligations | Payment Guarantee  
Concentration Risk [Line Items]  
Guarantee obligation at carrying value $ 113,000