Summary of Property and Equipment (Detail) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property Plant And Equipment [Abstract]
Land and land improvements	$ 2,047	$ 2,044
Buildings and leasehold improvements	13,483	13,472
Furniture and equipment	2,377	2,283
Construction in progress	86	289
Property, Plant and Equipment, Gross, Total	17,993	18,088
Less accumulated depreciation and amortization	(7,848)	(7,505)
Property and equipment, net	$ 10,145	$ 10,583	$ 10,494