Capital Stock - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended		6 Months Ended
	Jun. 10, 2013	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Equity [Abstract]
Options and restricted stock, anti-dilutive		8,300,000	3,200,000	8,300,000	5,000,000
Dividends, Common stock		$ 95	$ 97	$ 189	$ 192
Common stock share purchase, shares		40,000,000		40,000,000
Common stock share repurchase, shares	32,200,000
Common stock share repurchase, per share	$ 88.96