XML 101 R80.htm IDEA: XBRL DOCUMENT v3.8.0.1
Retirement and Postretirement Plans - Schedule of Expected Plan Contributions (Details)
$ in Thousands
Dec. 31, 2017
USD ($)
Pension Benefits [Member]  
Employer Contributions  
2018 to participant benefits $ 3,714
Expected Benefit Payments  
2018 29,163
2019 29,904
2020 29,596
2021 29,408
2022 29,155
2023-2027 142,107
OPEB [Member]  
Employer Contributions  
2018 to participant benefits 1,882
Expected Benefit Payments  
2018 1,882
2019 1,862
2020 1,839
2021 1,801
2022 1,788
2023-2027 $ 8,271