Fair Value Measurements (Financial Instruments At Fair Value, Excluding Derivative Financial Instruments) (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Fair Value [Member]
Financial assets:
Investments	$ 336		$ 263
Other	31		33
Total financial assets	367		296
Financial liabilities:
Long-term debt	3,306	[1]	3,559	[1]
Deferred credits and other liabilities	21		23
Total financial liabilities	3,327		3,582
Carrying Value [Member]
Financial assets:
Investments	14		59
Other	30		31
Total financial assets	44		90
Financial liabilities:
Long-term debt	3,001	[1]	3,006	[1]
Deferred credits and other liabilities	21		23
Total financial liabilities	$ 3,022		$ 3,029

[1] Excludes capital leases