Segment Information - Revenues and Segment Earnings (Parenthetical) (Detail) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Segment Reporting Information [Line Items]    
Total revenues $ 1,415 $ 1,458
Operating Segments [Member]    
Segment Reporting Information [Line Items]    
Total revenues 718 763
Operating Segments [Member] | United States [Member] | Hotels [Member]    
Segment Reporting Information [Line Items]    
Total revenues $ 267 $ 263
Maximum [Member]    
Segment Reporting Information [Line Items]    
Total revenues, percentage 10.00% 10.00%