Income Taxes (Income Tax (Expense) Benefit Allocated to Other Items) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Income Tax Disclosure [Abstract]
Unrecognized net periodic pension and other postretirement benefit cost(1)	$ 0	[1]	$ 0	[1]	$ 5	[1]
Unrealized holding gains/losses on securities(1)	$ 0	[1]	$ (1)	[1]	$ 1	[1]

[1] (1)These amounts have been recognized in accumulated other comprehensive loss.