Business Segments - Segment Revenues (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 3,772	$ 3,513
Total segment
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	3,710	3,455
Other unallocated corporate
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	62	58
North American Full-Service Segment | Total segment
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	2,321	2,175
North American Limited-Service Segment | Total segment
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	833	738
International | Total segment
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 556	$ 542