Equity Investments (Schedule of Financial Information Related to Unconsolidated Entities Included in Consolidated Statement of Income) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Equity Investments [Abstract]
Revenues	$ 339	$ 320	$ 672	$ 636
Operating costs and expenses	297	268	591	551
Income from continuing operations before taxes	$ 42	$ 52	$ 81	$ 84