Benefit Plans (Funded Status) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at January 1	$ 3,271	$ 3,003
Service cost	12	12	13
Interest cost	121	135	146
Participants' contributions
Actuarial (gain) loss	(289)	266
Benefits paid	(165)	(164)
Settlements	(8)
Foreign currency translation and other	1	19
Benefit obligation at December 31	2,943	3,271	3,003
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at January 1	2,425	2,212
Actual return on plan assets	311	245
Company contributions	92	115
Participants' contributions
Benefits paid	(165)	(164)
Settlements	(8)
Foreign currency translation and other	1	17
Fair value of plan assets at December 31	2,656	2,425	2,212
Defined Benefit Plan, Funded Status of Plan [Abstract]
Funded status	(287)	(846)
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Other assets	9
Other liabilities	(296)	(846)
Net amount recognized on balance sheets	(287)	(846)
Amounts recognized in Accumulated other comprehensive income not yet recognized in net periodic cost (benefit)[Abstract]
Prior service credit
Net actuarial (gain) loss	745	1,213
Net amount recognized in Accumulated other comprehensive income	745	1,213
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at January 1	47	49
Service cost	1		1
Interest cost	1	2	3
Participants' contributions	5	5
Actuarial (gain) loss	(3)	3
Benefits paid	(12)	(12)
Settlements
Foreign currency translation and other	1
Benefit obligation at December 31	40	47	49
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at January 1
Actual return on plan assets
Company contributions	7	7
Participants' contributions	5	5
Benefits paid	(12)	(12)
Settlements
Foreign currency translation and other
Fair value of plan assets at December 31
Defined Benefit Plan, Funded Status of Plan [Abstract]
Funded status	(40)	(47)
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Other assets
Other liabilities	(40)	(47)
Net amount recognized on balance sheets	(40)	(47)
Amounts recognized in Accumulated other comprehensive income not yet recognized in net periodic cost (benefit)[Abstract]
Prior service credit	(98)	(116)
Net actuarial (gain) loss	8	11
Net amount recognized in Accumulated other comprehensive income	$ (90)	$ (105)