Retirement Plans and Other Retiree Benefits (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Pension Benefits, United States
Components of net periodic benefit cost
Service cost	$ 0	$ 0
Interest cost	24	27
ESOP offset	0	0
Expected return on plan assets	(27)	(27)
Amortization of transition and prior service costs (credits)	0	0
Amortization of actuarial loss (gain)	12	10
Net periodic benefit cost	9	10
Voluntary benefit plan contribution	57	50
Pension Benefits, International
Components of net periodic benefit cost
Service cost	4	4
Interest cost	5	6
ESOP offset	0	0
Expected return on plan assets	(5)	(5)
Amortization of transition and prior service costs (credits)	0	0
Amortization of actuarial loss (gain)	2	2
Net periodic benefit cost	6	7
Other Retiree Benefits
Components of net periodic benefit cost
Service cost	4	3
Interest cost	11	11
ESOP offset	0	0
Expected return on plan assets	0	0
Amortization of transition and prior service costs (credits)	0	0
Amortization of actuarial loss (gain)	4	4
Net periodic benefit cost	$ 19	$ 18