Quarterly report pursuant to Section 13 or 15(d)

Commitments and Contingent Liabilities (Details)

v3.8.0.1
Commitments and Contingent Liabilities (Details) - USD ($)
$ in Thousands
 1 Months Ended
Sep. 30, 2017
Nov. 30, 2015
Dec. 31, 2016
Dec. 31, 2005
Asbestos Removal and Insulation Replacement        
Loss Contingencies [Line Items]        
Accrual for environmental loss contingencies $ 573   $ 532  
Soil and Groundwater Contamination        
Loss Contingencies [Line Items]        
Accrual for environmental loss contingencies 839   913  
Subsurface Remedial and Wetlands/Marsh Management        
Loss Contingencies [Line Items]        
Accrual for environmental loss contingencies 1,380   1,776  
Subsurface Remediation and Soil Vapor Extraction        
Loss Contingencies [Line Items]        
Accrual for environmental loss contingencies 1,444   1,755  
New Jersey Locations | PCB Remediation        
Loss Contingencies [Line Items]        
Accrual for environmental loss contingencies 557   700 $ 500
Chester And Baltimore Facilities | PCB Remediation        
Loss Contingencies [Line Items]        
Accrual for environmental loss contingencies 236   1,048  
Pending Litigation | PADEP        
Loss Contingencies [Line Items]        
Value sought by counterparty 215 $ 1,739    
Settlement amount awarded to counterparty   $ 1,550    
Judicial Ruling | PADEP        
Loss Contingencies [Line Items]        
Accrual for environmental loss contingencies $ 215   $ 1,500