Summary of Property and Equipment (Detail) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Property Plant And Equipment [Abstract]
Land and land improvements	$ 2,061	$ 2,044
Buildings and leasehold improvements	13,504	13,472
Furniture and equipment	2,339	2,283
Construction in progress	240	289
Property, Plant and Equipment, Gross, Total	18,144	18,088
Less accumulated depreciation and amortization	(7,692)	(7,505)
Property and equipment, net	$ 10,452	$ 10,583