Intangible Assets (Narrative) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense relating to all intangible assets	$ 9	$ 7	$ 16	$ 12
Amortization expense for remainder of the year	18		18
Intangible assets amortization expense, year one	32		32
Intangible assets amortization expense, year two	32		32
Intangible assets amortization expense, year three	32		32
Intangible assets amortization expense, year four	32		32
Intangible assets amortization expense, year five	$ 32		$ 32