Share-Based Compensation (PSU Compensation Expense) (Details) (PSUs, USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense	$ 4		$ 5		$ 5
Tax benefit	(1)		(1)		(1)
Total expense, net of tax	3		4		4
Total intrinsic value of options exercised	0	[1]	0	[1]	0	[1]
Total fair value of options vested	$ 0		$ 2		$ 0

[1] Amount represents fair market value on the date of conversion.