XML 75 R53.htm IDEA: XBRL DOCUMENT v3.8.0.1
Summary of Significant Accounting Policies - Warranties
12 Months Ended
Dec. 31, 2017
Minimum  
Product Warranty Liability [Line Items]  
Product warranty period against materials and manufacturing defects 1 year
Maximum  
Product Warranty Liability [Line Items]  
Product warranty period against materials and manufacturing defects 5 years