Employee Retirement Benefits (Status of Pension and Other Postretirement Plans) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Pension Plans [Member]
Change in Projected Benefit Obligation [Roll Forward]
Projected benefit obligation at beginning of year	$ 1,724,000,000		$ 1,452,000,000
Service cost	22,000,000		37,000,000		39,000,000
Interest cost	68,000,000		72,000,000		72,000,000
Plan participants' contributions	0		0
Net actuarial loss (gain)	15,000,000		198,000,000
Curtailment	(142,000,000)		0
Benefits paid	(39,000,000)		(35,000,000)
Projected benefit obligation at end of year	1,648,000,000		1,724,000,000		1,452,000,000
Change in Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	1,227,000,000		1,042,000,000
Actual return on plan assets	111,000,000		136,000,000
Employer contributions	25,000,000		84,000,000
Plan participants' contributions	0		0
Benefits paid	(39,000,000)		(35,000,000)
Fair value of plan assets at end of year	1,324,000,000		1,227,000,000		1,042,000,000
Funded status at end of year	(324,000,000)	[1]	(497,000,000)	[1]
Accumulated benefit obligation for our pension plans			1,600,000,000
Other Postretirement Plans [Member]
Change in Projected Benefit Obligation [Roll Forward]
Projected benefit obligation at beginning of year	201,000,000		183,000,000
Service cost	6,000,000		6,000,000		6,000,000
Interest cost	8,000,000		9,000,000		9,000,000
Plan participants' contributions	2,000,000		2,000,000
Net actuarial loss (gain)	(34,000,000)		9,000,000
Curtailment	0		0
Benefits paid	(8,000,000)		(8,000,000)
Projected benefit obligation at end of year	175,000,000		201,000,000		183,000,000
Change in Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0		0
Actual return on plan assets	0		0
Employer contributions	6,000,000		6,000,000
Plan participants' contributions	2,000,000		2,000,000
Benefits paid	(8,000,000)		(8,000,000)
Fair value of plan assets at end of year	0		0		0
Funded status at end of year	$ (175,000,000)	[1]	$ (201,000,000)	[1]

[1] in “Other liabilities” in our consolidated balance sheets as of December 31, 2013 and 2012.