Accrued Expenses - Components of Current Liabilities (Details) - USD ($)
$ in Thousands
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Payables and Accruals [Abstract]      
Salaries and wages $ 32,959 $ 41,216  
Warranty cost 23,302 22,820 $ 30,738
Taxes other than income taxes, primarily Value Added Taxes 19,194 21,424  
Freight 5,211 5,978  
Professional 4,728 5,774  
Product liability, current portion 3,996 3,127  
Interest 3,747 872  
Severance 2,049 2,477  
Derivatives (foreign currency forward exchange contracts) 1,783 2,014  
Deferred revenue 1,446 400  
Insurance 742 695  
Rent 672 402  
Supplemental Executive Retirement Plan (SERP) 391 1,279  
Rebates 356 1,791  
Other items, principally trade accruals 9,519 8,687  
Accrued expenses $ 110,095 $ 118,956