Retirement Plans and Other Retiree Benefits (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Pension Benefits, United States
Components of net periodic benefit cost
Service cost	$ 0	$ 0
Interest cost	27	25
ESOP offset	0	0
Expected return on plan assets	(27)	(29)
Amortization of transition and prior service costs (credits)	0	0
Amortization of actuarial loss (gain)	10	12
Net periodic benefit cost	10	8
Voluntary benefit plan contribution	50	0
Pension Benefits, International
Components of net periodic benefit cost
Service cost	4	5
Interest cost	6	8
ESOP offset	0	0
Expected return on plan assets	(5)	(8)
Amortization of transition and prior service costs (credits)	0	0
Amortization of actuarial loss (gain)	2	3
Net periodic benefit cost	7	8
Other Retiree Benefits
Components of net periodic benefit cost
Service cost	3	4
Interest cost	11	11
ESOP offset	0	0
Expected return on plan assets	0	(1)
Amortization of transition and prior service costs (credits)	0	0
Amortization of actuarial loss (gain)	4	7
Net periodic benefit cost	$ 18	$ 21