Summary of Accounting Policies (Schedule of Change in Accounting Policy For Pension and Other Postretirement Benefits - Consolidated Balance Sheets) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings	$ 3,011	$ 1,993
Accumulated other comprehensive income (loss), net	(4)	(89)	(90)	(90)
Previous Accounting Method [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings	3,815	2,986
Accumulated other comprehensive income (loss), net	(808)	(1,082)
Effect of Change [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings	(804)	(993)	(760)
Accumulated other comprehensive income (loss), net	$ 804	$ 993