v3.7.0.1
Employee Benefit Plans (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2017
Mar. 31, 2016
U.S. (Pension Benefits) [Member]    
Components of Net Periodic Benefit Cost    
Service cost $ 23 $ 27
Interest cost 32 40
Expected return on plan assets (34) (43)
Amortization of prior service cost (credit) 1 1
Recognized net actuarial (gain) loss 19 19
Settlements 60 82
Net periodic benefit cost 101 126
Int'l (Pension Benefits) [Member]    
Components of Net Periodic Benefit Cost    
Service cost 19 20
Interest cost 26 31
Expected return on plan assets (39) (41)
Amortization of prior service cost (credit) (1) (1)
Recognized net actuarial (gain) loss 12 7
Settlements 0 0
Net periodic benefit cost 17 16
Other Benefits [Member]    
Components of Net Periodic Benefit Cost    
Service cost 0 1
Interest cost 2 3
Expected return on plan assets 0 0
Amortization of prior service cost (credit) (9) (9)
Recognized net actuarial (gain) loss (1) 0
Settlements 0 0
Net periodic benefit cost $ (8) $ (5)