Pension and Other Postemployment Benefits (Details 1) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Pensions
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 197	$ 161	$ 130
Interest cost	372	389	374
Expected return on plan assets	(501)	(486)	(446)
Amortization of prior service cost (credit)	12	12	14
Other adjustments (settlements, curtailments, etc.)	0	0	6
Pensions & OPEB mark-to-market adjustment	(267)	735	729
Net periodic cost (credit)	(187)	811	807
OPEB
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	13	12	13
Interest cost	37	47	48
Expected return on plan assets	(34)	(37)	(40)
Amortization of prior service cost (credit)	(207)	(203)	(203)
Other adjustments (settlements, curtailments, etc.)	0	0	0
Pensions & OPEB mark-to-market adjustment	(129)	140	36
Net periodic cost (credit)	$ (320)	$ (41)	$ (146)