Pensions and Other Postretirement Benefits (Net Periodic Benefit Costs) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 15	$ 14	$ 30	$ 27
Interest cost	53	59	103	118
Expected return on plan assets	(69)	(74)	(139)	(148)
Amortization of actuarial losses	25	20	55	40
Amortization of prior service cost	0	(1)	(1)	(1)
Settlement Losses	0	(5)	0	(5)
Curtailments and special termination benefits	1	0	1	0
Net periodic pension/other postretirement benefit cost	25	23	49	41
Other Postretirement Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	5	5	10	9
Interest cost	12	13	24	25
Amortization of actuarial losses	8	(3)	16	(5)
Amortization of prior service cost	(2)	3	(5)	7
Net periodic pension/other postretirement benefit cost	$ 23	$ 18	$ 45	$ 36