Annual report pursuant to Section 13 and 15(d)

Postretirement Benefits, Schedule of Amounts Recognized in Other Comprehensive Income (Details)

v3.6.0.2
Postretirement Benefits, Schedule of Amounts Recognized in Other Comprehensive Income (Details) - USD ($)
$ in Thousands
Dec. 31, 2016
Dec. 31, 2015
Schedule of Amounts Recognized in Other Comprehensive Income    
Net actuarial loss $ (42,692) $ (42,091)
Prior service credit 174 225
Total $ (42,518) $ (41,866)