Employee Benefit Plans (Net Periodic Benefit Costs) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Pension Benefits U.S. Plans [Member]
Components of net periodic benefit costs
Service costs	$ 54	$ 50
Interest costs	101	109
Expected return on plan assets	(134)	(119)
Amortization of net actuarial (gains) losses	47	41
Amortization of prior service costs (credit)	0	1
Net periodic benefit costs	68	82
Pension Benefits Non-U.S. Plans [Member]
Components of net periodic benefit costs
Service costs	15	20
Interest costs	4	3
Expected return on plan assets	(2)	(2)
Amortization of net actuarial (gains) losses	1	0
Amortization of prior service costs (credit)	0	0
Net periodic benefit costs	18	21
Other Postretirement Benefits U.S. Plans [Member]
Components of net periodic benefit costs
Service costs	4	3
Interest costs	22	23
Expected return on plan assets	(20)	(19)
Amortization of net actuarial (gains) losses	10	3
Amortization of prior service costs (credit)	(1)	0
Net periodic benefit costs	15	10
Other Postretirement Benefits Non-U.S. Plans [Member]
Components of net periodic benefit costs
Service costs	0	0
Interest costs	1	1
Expected return on plan assets	0	0
Amortization of net actuarial (gains) losses	0	0
Amortization of prior service costs (credit)	0	0
Net periodic benefit costs	$ 1	$ 1