Employee Postretirement Benefits (Summarized Financial Information about Postretirement plans, Excluding Defined Contribution Retirement Plans) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Fair value of plan assets at end of year	$ 4,840,000,000	$ 4,192,000,000
Noncurrent liability - Accrued benefit cost	(1,460,000,000)	(1,810,000,000)
Defined Benefit Pension [Member]
Benefit obligation at beginning of year	5,658,000,000	5,491,000,000
Service cost	57,000,000	56,000,000	68,000,000
Interest cost	307,000,000	309,000,000	310,000,000
Actuarial loss (gain)	374,000,000	201,000,000
Currency and other	(103,000,000)	(19,000,000)
Benefit payments from plans	(359,000,000)	(356,000,000)
Direct benefit payments	(14,000,000)	(24,000,000)
Benefit obligation at end of year	5,920,000,000	5,658,000,000	5,491,000,000
Fair value of plan assets at beginning of year	4,600,000,000	4,244,000,000
Actual gain on plan assets	309,000,000	473,000,000
Employer contributions	679,000,000	245,000,000
Currency and other	(15,000,000)	(6,000,000)
Benefit Payments	(359,000,000)	(356,000,000)
Fair value of plan assets at end of year	5,214,000,000	4,600,000,000	4,244,000,000
Funded Status	(706,000,000)	(1,058,000,000)
Noncurrent asset - Prepaid benefit cost	20,000,000	21,000,000
Current liability - Accrued benefit cost	(13,000,000)	(11,000,000)
Noncurrent liability - Accrued benefit cost	(713,000,000)	(1,068,000,000)
Net amount recognized	(706,000,000)	(1,058,000,000)
Other Postretirement Benefit Plans, Defined Benefit [Member]
Benefit obligation at beginning of year	796,000,000	795,000,000
Service cost	14,000,000	14,000,000	14,000,000
Interest cost	41,000,000	44,000,000	47,000,000
Actuarial loss (gain)	33,000,000	(10,000,000)
Currency and other	(22,000,000)	17,000,000
Benefit payments from plans	0	0
Direct benefit payments	(74,000,000)	(64,000,000)
Benefit obligation at end of year	788,000,000	796,000,000	795,000,000
Fair value of plan assets at beginning of year	0	0
Actual gain on plan assets	0	0
Employer contributions	0	0
Currency and other	0	0
Benefit Payments	0	0
Fair value of plan assets at end of year	0	0	0
Funded Status	(788,000,000)	(796,000,000)
Noncurrent asset - Prepaid benefit cost	0	0
Current liability - Accrued benefit cost	(59,000,000)	(64,000,000)
Noncurrent liability - Accrued benefit cost	(729,000,000)	(732,000,000)
Net amount recognized	$ (788,000,000)	$ (796,000,000)