Pension and Other Postretirement Employee Benefit Plans - Net Periodic Benefit Costs (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Defined Benefit Pension Plans, U.S. [Member]
Components of net periodic benefit cost [Abstract]
Benefits earned during the year	$ 68	$ 62
Interest cost on benefit obligations	106	113
Expected return on plan assets	(195)	(198)
Amortization:
Net loss	72	41
Prior service cost (credit)	(11)	(10)
Net periodic defined benefit cost	40	8
Other defined benefit pension plans	4	7
Total defined benefit plans	44	15
Total defined contribution plans	81	78
Total pension and OPEB cost included in compensation expense	125	93
Defined Benefit Pension Plans, Non-U.S. [Member]
Components of net periodic benefit cost [Abstract]
Benefits earned during the year	10	9
Interest cost on benefit obligations	31	33
Expected return on plan assets	(33)	(36)
Amortization:
Net loss	9	12
Prior service cost (credit)	0	0
Net periodic defined benefit cost	17	18
Other defined benefit pension plans	2	4
Total defined benefit plans	19	22
Total defined contribution plans	80	78
Total pension and OPEB cost included in compensation expense	99	100
OPEB Plans [Member]
Components of net periodic benefit cost [Abstract]
Benefits earned during the year	0	0
Interest cost on benefit obligations	11	13
Expected return on plan assets	(22)	(22)
Amortization:
Net loss	2	0
Prior service cost (credit)	0	(2)
Net periodic defined benefit cost	(9)	(11)
Total defined benefit plans	(9)	(11)
Total pension and OPEB cost included in compensation expense	$ (9)	$ (11)