Changes in Outstanding SARs (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 28, 2012
Weighted Average Exercise Price
Granted (per unit)	$ 17	$ 13	$ 12
Outstanding ending balance (per unit)	$ 36
Stock Appreciation Rights
Number of SARs (in millions)
Outstanding beginning balance	6,400,000
Granted	300,000
Exercised	(900,000)
Forfeited	0
Outstanding ending balance	5,800,000
Weighted Average Exercise Price
Outstanding beginning balance (per unit)	$ 32
Granted (per unit)	$ 53
Exercised (in shares)	$ 31
Forfeited (per unit)	$ 0
Outstanding ending balance (per unit)	$ 33