Short-Term and Long-Term Debt (Schedule of Extinguishment of Debt) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Details underlying the recognition of gain or loss on extinguishment of debt [Abstract]
Principal balance outstanding prior to payoff		[1]		[1]	$ 15	[1]
Unamortized debt issuance costs and discounts prior to payoff
Amount paid to retire					(20)
Gain (loss) on extinguishment of debt, pre-tax					(5)
Parent Company [Member]
Details underlying the recognition of gain or loss on extinguishment of debt [Abstract]
Gain (loss) on extinguishment of debt, pre-tax					$ 5

[1] During the fourth quarter of 2012, we repurchased $13 million of our 8.75% senior notes due 2019 and $2 million of our 6.15% senior notes due 2036.