Asset Dispositions and Impairments - Additional Information (Detail) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015 USD ($) Hotel	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($) Hotel	Sep. 30, 2014 USD ($) Hotel
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Number of wholly-owned hotels sold | Hotel	1		3	2
Net of closing costs, cash proceeds from disposal of assets	$ 240		$ 527	$ 223
Impairment charge	31	$ 13
Pre-tax gain (loss) on sale of assets and asset impairment charges	(12)
Gain related to sale of a minority partnership interest			17
Asset dispositions and impairments associated with certain hotel renovations			$ 7
Foreign unconsolidated joint ventures [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Impairment charge				7
Management agreements [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Number of wholly-owned hotels sold | Hotel			2
Deferred gain on dispositions of assets	$ 128		$ 240	$ 91
Number of wholly-owned hotels agreed to sell | Hotel				1
Long-term franchise agreements [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Pre-tax gain (loss) on sale of assets and asset impairment charges		$ (7)	$ 4	$ (6)
Managed hotel [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Pre-tax gain (loss) on sale of assets and asset impairment charges				$ (21)