Employee Benefit Plans (Net Periodic Benefit Costs) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
United States Pension Plans of US Entity, Defined Benefit [Member]
Components of net periodic benefit costs
Service costs	$ 59	$ 56	$ 177	$ 168
Interest costs	98	102	292	305
Expected return on plan assets	(121)	(121)	(363)	(363)
Amortization of net actuarial (gains) losses	57	48	171	146
Amortization of prior service costs (credit)	2	2	5	5
Net periodic benefit costs	95	87	282	261
Foreign Pension Plans, Defined Benefit [Member]
Components of net periodic benefit costs
Service costs	16	19	50	55
Interest costs	4	4	11	13
Expected return on plan assets	(2)	(1)	(5)	(5)
Amortization of net actuarial (gains) losses	0	0	0	0
Amortization of prior service costs (credit)	0	0	0	0
Net periodic benefit costs	18	22	56	63
United States Postretirement Benefit Plans of US Entity, Defined Benefit [Member]
Components of net periodic benefit costs
Service costs	5	5	15	16
Interest costs	23	26	69	77
Expected return on plan assets	(18)	(19)	(56)	(57)
Amortization of net actuarial (gains) losses	14	15	41	43
Amortization of prior service costs (credit)	(19)	(26)	(56)	(78)
Net periodic benefit costs	5	1	13	1
Foreign Postretirement Benefit Plans, Defined Benefit [Member]
Components of net periodic benefit costs
Service costs	0	0	1	1
Interest costs	1	1	2	2
Expected return on plan assets	(1)	(1)	(1)	(1)
Amortization of net actuarial (gains) losses	0	1	0	1
Amortization of prior service costs (credit)	0	0	0	0
Net periodic benefit costs	0	1	2	3
Qualified Plan Pension Plan [Member] | United States Pension Plans of US Entity, Defined Benefit [Member]
Components of net periodic benefit costs
Discretionary contributions			$ 313