Employee Benefit Plans (Net Periodic Benefit Costs) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
United States Pension Plans of US Entity, Defined Benefit [Member]
Components of net periodic benefit costs
Service costs	$ 59	$ 56	$ 118	$ 112
Interest costs	97	102	194	203
Expected return on plan assets	(121)	(121)	(242)	(242)
Amortization of net actuarial (gains) losses	57	49	114	98
Amortization of prior service costs (credit)	0	1	3	3
Net periodic benefit costs	92	87	187	174
Foreign Pension Plans, Defined Benefit [Member]
Components of net periodic benefit costs
Service costs	17	16	34	36
Interest costs	3	5	7	9
Expected return on plan assets	(1)	(2)	(3)	(4)
Amortization of net actuarial (gains) losses	0	0	0	0
Amortization of prior service costs (credit)	0	0	0	0
Net periodic benefit costs	19	19	38	41
United States Postretirement Benefit Plans of US Entity, Defined Benefit [Member]
Components of net periodic benefit costs
Service costs	5	6	10	11
Interest costs	23	25	46	51
Expected return on plan assets	(19)	(19)	(38)	(38)
Amortization of net actuarial (gains) losses	13	14	27	28
Amortization of prior service costs (credit)	(18)	(26)	(37)	(52)
Net periodic benefit costs	4	0	8	0
Foreign Postretirement Benefit Plans, Defined Benefit [Member]
Components of net periodic benefit costs
Service costs	1	1	1	1
Interest costs	0	0	1	1
Expected return on plan assets	0	0	0	0
Amortization of net actuarial (gains) losses	0	0	0	0
Amortization of prior service costs (credit)	0	0	0	0
Net periodic benefit costs	$ 1	$ 1	$ 2	$ 2