v3.21.2
Employee Benefit Plans - Components of Net Periodic Benefit Cost (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2021
Mar. 31, 2021
Sep. 30, 2020
Sep. 30, 2021
Sep. 30, 2020
Pension Plans Defined Benefit [Member] | U.S.          
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]          
Service cost $ 17   $ 21 $ 56 $ 63
Interest cost 12   17 40 51
Expected return on plan assets (22)   (21) (66) (63)
Amortization of prior service cost (credit) 0   0 0 0
Recognized net actuarial (gain) loss 9   12 36 37
Settlements 28   27 72 28
Curtailments   $ 12   12 0
Special Termination Benefits       9 0
Net periodic benefit cost 44   56 159 116
Pension Plans Defined Benefit [Member] | Int'l (Pension Benefits) [Member]          
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]          
Service cost 15   14 46 41
Interest cost 19   21 59 63
Expected return on plan assets (30)   (37) (90) (108)
Amortization of prior service cost (credit) 0   (1) 0 (1)
Recognized net actuarial (gain) loss 8   5 24 16
Settlements 0   0 0 (1)
Curtailments       0 0
Special Termination Benefits       0 0
Net periodic benefit cost 12   2 39 10
Other Postretirement Benefit Plans, Defined Benefit [Member]          
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]          
Service cost 0   1 1 2
Interest cost 1   2 3 5
Expected return on plan assets 0   0 0 0
Amortization of prior service cost (credit) (9)   (7) (28) (23)
Recognized net actuarial (gain) loss 0   1 1 1
Settlements 0   0 0 0
Curtailments       0 0
Special Termination Benefits       0 0
Net periodic benefit cost $ (8)   $ (3) $ (23) $ (15)