v3.3.1.900
Retirement Benefits Plans Retirement Benefits Plans - Discount Rates (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Retirement Benefits Plans - Discount Rates [Line Items]    
Discount Rates for Service and Interest Costs   4.00%
Scenario, Forecast [Member]    
Retirement Benefits Plans - Discount Rates [Line Items]    
Discount Rate Service Costs 4.30%  
Discount Rate Interest Costs 3.30%  
Service Cost Reduction $ 3  
Interest Cost Reduction $ 42