Asset Dispositions and Impairments - Additional Information (Detail) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2015 USD ($) Hotel	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($) Hotel	Dec. 31, 2014 USD ($)
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Number of wholly-owned hotels sold | Hotel	3		2
Net of closing costs, cash proceeds from disposal of assets	$ 527		$ 223
Deferred gain on dispositions of assets	1,341	$ 1,341		$ 1,168
Asset dispositions and impairments associated with certain hotel renovations	$ 4	3
Gain related to sale of a minority partnership interest		17
Impairment associated with one of our foreign unconsolidated joint ventures			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	$ 240	$ 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]
Number of wholly-owned hotels sold | Hotel	1
Pre-tax gain (loss) on sale of assets	$ 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)