Summary of Property and Equipment (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Property Plant And Equipment [Abstract]
Land and land improvements	$ 2,059	$ 2,044
Buildings and leasehold improvements	13,696	13,472
Furniture and equipment	2,388	2,283
Construction in progress	109	289
Property, Plant and Equipment, Gross, Total	18,252	18,088
Less accumulated depreciation and amortization	(7,873)	(7,505)
Property and equipment, net	$ 10,379	$ 10,583