Postretirement Benefits (Details 8) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 participant	Dec. 31, 2012 participant
Amounts recognized in other comprehensive income for pension plans:
Amortization of net actuarial loss	$ (15)	$ (11)
Amortization of prior service cost	(1)	(1)
Net actuarial (gain) loss arising during the year	(110)	59
Amendments	1	0
Total recognized in other comprehensive income	$ (125)	$ 47
Number of new plan participants resulting in charges recognized as amendments (number of participants)	4	1