Quarterly report pursuant to Section 13 or 15(d)

Remediation Obligations (Details)

v3.7.0.1
Remediation Obligations (Details) - USD ($)
$ in Thousands
6 Months Ended
Jun. 30, 2017
Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]    
Site Contingency, Time Frame of Disbursements 15 years  
Accrual for Environmental Loss Contingencies $ 6,592 $ 6,592
Accrued Environmental Loss Contingencies, Current 796 796
Accrued Environmental Loss Contingencies, Noncurrent $ 5,796 $ 5,796