Activity Related to "Senior, mezzanine, and other loans" Notes Receivable Reserve (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 28, 2012
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	$ 90	$ 79	$ 78
Additions			2
Reversals		(2)	(1)
Write-offs	(45)		(1)
Transfers and other	5	13	1
Ending balance	$ 50	$ 90	$ 79