Summary of Property and Equipment (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Property Plant And Equipment [Abstract]
Land and land improvements	$ 1,993	$ 1,973
Buildings and leasehold improvements	13,318	13,435
Furniture and equipment	2,209	2,223
Construction in progress	188	176
Property, Plant and Equipment, Gross, Total	17,708	17,807
Less accumulated depreciation and amortization	(7,079)	(6,812)
Property and equipment, net	$ 10,629	$ 10,995