Intangible Assets (Narrative) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense relating to all intangible assets	$ 7	$ 5
Amortization expense for remainder of the year	25
Intangible assets amortization expense, year one	31
Intangible assets amortization expense, year two	31
Intangible assets amortization expense, year three	31
Intangible assets amortization expense, year four	31
Intangible assets amortization expense, year five	$ 31