Pension and Other Postretirement Benefit Plans (Change in Benefit Obligation) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan amendments	$ 148
United States Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit Obligation, beginning of year	3,605	3,637
Service cost	2	3	11
Interest cost	192	200	206
Plan participants’ contributions
Actuarial loss (gain)	318	57
Benefits paid, net of federal subsidy	(245)	(292)
Plan amendments
New plans
Settlements / Curtailment loss (gain)
Foreign currency exchange rates
Benefit Obligation, end of year	3,872	3,605	3,637
Accumulated benefit obligation, end of year	3,859	3,594
Foreign Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit Obligation, beginning of year	389	383
Service cost	7	6	6
Interest cost	20	20	20
Plan participants’ contributions	2	2
Actuarial loss (gain)	0	20
Benefits paid, net of federal subsidy	(31)	(45)
Plan amendments		2
New plans		10
Settlements / Curtailment loss (gain)		(2)
Foreign currency exchange rates	(14)	(7)
Benefit Obligation, end of year	373	389	383
Accumulated benefit obligation, end of year	353	359
Other Postretirement Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit Obligation, beginning of year	671	761
Service cost	8	9	11
Interest cost	31	38	48
Plan participants’ contributions	10	17
Actuarial loss (gain)	(6)	(40)
Benefits paid, net of federal subsidy	(74)	(73)
Plan amendments	(148)	(43)
New plans
Settlements / Curtailment loss (gain)
Foreign currency exchange rates	(4)	2
Benefit Obligation, end of year	488	671	761
Accumulated benefit obligation, end of year	$ 0	$ 0