Quarterly report pursuant to Section 13 or 15(d)

Recent Accounting Pronouncements (Details)

v3.7.0.1
Recent Accounting Pronouncements (Details) - Accounting Standards Update 2017-07 - USD ($)
$ in Thousands
6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]    
Net periodic benefit cost for pensions and other postretirement benefits $ 638 $ 611
Service cost $ 280 $ 265