XML 59 R47.htm IDEA: XBRL DOCUMENT v3.7.0.1
Fair Value Measurements (Details 5) - USD ($)
$ in Millions
Mar. 31, 2017
Dec. 31, 2016
Carrying Value    
Fair value and related carrying amounts of long-term debt and other long-term obligations    
Long-term debt and other long-term obligations $ 19,921 $ 19,885
Carrying Value | FES    
Fair value and related carrying amounts of long-term debt and other long-term obligations    
Long-term debt and other long-term obligations 2,971 3,000
Fair Value    
Fair value and related carrying amounts of long-term debt and other long-term obligations    
Long-term debt and other long-term obligations 20,029 19,829
Fair Value | FES    
Fair value and related carrying amounts of long-term debt and other long-term obligations    
Long-term debt and other long-term obligations $ 1,424 $ 1,555