Schedule Of Rent Expense (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Rent and minimum concession fees	$ 699	$ 679	$ 639
Contingent concession expense	214	195	193
Rent and contingent concession expense	913	874	832
Less: sublease rental income	(5)	(5)	(6)
Total	$ 908	$ 869	$ 826