Employee Benefit Plans (Details 6) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011
United States Pension Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
Defined Benefit Plan, Expected Future Benefit Payments in Year One	$ 1,060
Defined Benefit Plan, Expected Future Benefit Payments in Year Two	1,070
Defined Benefit Plan, Expected Future Benefit Payments in Year Three	1,080
Defined Benefit Plan, Expected Future Benefit Payments in Year Four	1,097
Defined Benefit Plan, Expected Future Benefit Payments in Year Five	1,116
Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter	5,925
United States Postretirement Benefit Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
Defined Benefit Plan, Expected Future Benefit Payments in Year One	264
Defined Benefit Plan, Expected Future Benefit Payments in Year Two	263
Defined Benefit Plan, Expected Future Benefit Payments in Year Three	261
Defined Benefit Plan, Expected Future Benefit Payments in Year Four	261
Defined Benefit Plan, Expected Future Benefit Payments in Year Five	264
Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter	$ 1,394