XML 93 R78.htm IDEA: XBRL DOCUMENT v3.8.0.1
One Percentage Point Change in Health Care Cost Trend Rates (Details)
$ in Thousands
12 Months Ended
Dec. 31, 2017
USD ($)
Defined Benefit Plan, Effect of One-Percentage Point Change in Assumed Health Care Cost Trend Rates [Abstract]  
Effect of 1% increase on total service and interest cost components $ 193
Effect of 1% decrease on total service and interest cost components (168)
Effect of 1% increase on postretirement employee benefit obligation 4,150
Effect of 1% decrease on postretirement employee benefit obligation $ (3,614)