Changes in Shareholders' Deficit (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended				6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 Class A Common Stock	Dec. 31, 2013 Class A Common Stock	Jun. 30, 2014 Additional Paid-in-Capital	Jun. 30, 2014 Retained Earnings	Jun. 30, 2014 Treasury Stock, at Cost	Jun. 30, 2014 Accumulated Other Comprehensive (Loss) Income
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Balance at year-end 2013			$ (1,415)		$ 5	$ 5	$ 2,716	$ 3,837	$ (7,929)	$ (44)
Balance at year-end 2013, shares			298.0
Net income	192	179	364	315				364
Other comprehensive income	2	(8)	5	(10)						5
Cash dividends ($0.3700 per share)			(109)					(109)
Employee stock plan issuance			90				(9)	(62)	161
Employee stock plan issuance, shares			4.7
Purchase of treasury stock			(655)					0	(655)
Purchase of treasury stock, shares			(12.0)
Balance at June 30, 2014	$ (1,720)		$ (1,720)		$ 5	$ 5	$ 2,707	$ 4,030	$ (8,423)	$ (39)
Balance at March 31, 2014, shares	290.7		290.7
Cash dividends, per share (in USD per share)			$ 0.3700