XML 115 R97.htm IDEA: XBRL DOCUMENT v3.3.1.900
Employee Benefit Plans (Schedule of Expected Benefit Payments) (Details) - Postretirement Medical and Life Benefit Plan
$ in Thousands
Dec. 31, 2015
USD ($)
Defined Benefit Plan Disclosure [Line Items]  
2016 $ 62
2017 71
2018 76
2019 76
2020 81
2021-2025 $ 356