Postretirement Benefit Plans (Details 3) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure
Benefit obligation at end of year	$ 840	$ 855
Other postretirement benefit plans
Defined Benefit Plan Disclosure
Benefit obligation at beginning of year	65	46
Service cost	1	1	1
Interest cost	3	3	1
Actuarial loss	(2)	15
Benefits paid	(3)	(3)
Other	(1)	3
Benefit obligation at end of year	$ 63	$ 65	$ 46