XML 132 R113.htm IDEA: XBRL DOCUMENT v3.3.1.900
Postretirement Benefits Other Than Pensions - Actuarial Assumptions of OPEB Expense (Details) - Other Postretirement Benefit Plan, Defined Benefit [Member]
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]      
Discount Rate 3.40% 4.00% 3.15%
Rate of Increase in Future Compensation Levels 2.68% 2.10% 2.10%