XML 110 R92.htm IDEA: XBRL DOCUMENT v3.8.0.1
Operating Segments - Geographic Data (Details) - USD ($)
$ in Millions
3 Months Ended 12 Months Ended
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Geographic Data                      
Revenues $ 7,605 $ 5,873 $ 6,078 $ 6,667 $ 5,952 $ 5,170 $ 4,950 $ 4,111 $ 26,223 $ 20,182 $ 23,152
Long-lived assets 21,346       19,936       21,346 19,936  
United States                      
Geographic Data                      
Revenues                 21,443 15,599 18,701
Long-lived assets 17,167       16,041       17,167 16,041  
Canada                      
Geographic Data                      
Revenues                 4,780 4,583 $ 4,451
Long-lived assets $ 4,179       $ 3,895       $ 4,179 $ 3,895