Equity Method Investments (Summarized Financial Information For Equity Method Investees) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income statement data:
Revenues and other income	$ 1,067	$ 1,025	$ 1,043
Income from operations	87	73	128
Net income	63	47	101
Balance sheet data - December 31:
Current assets	339	217
Noncurrent assets	1,238	1,163
Current liabilities	145	161
Noncurrent liabilities	$ 618	$ 636