Acquisitions and Dispositions - Dispositions and Planned Dispositions (Details) € in Millions, $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Mar. 31, 2015 EUR (€)	Mar. 31, 2014 USD ($) hotel	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Dispositions					$ 581	$ 292
Current assets of dispositions	$ 145				145		$ 233
Assets held for sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Current assets of dispositions	145				145
Accrued expenses and other
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Current liabilities of dispositions	15				15
International
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of interest in a limited service property		$ 27	€ 24
Current assets of dispositions	60				60
Current liabilities of dispositions	6				6
Gain and other income, net | International
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of long-lived assets	18
Gain and other income, net | North American Limited-Service Segment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of long-lived assets	4
EDITION Hotels
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of hotels | hotel				3
Dispositions				$ 816
London EDITION Hotel
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of property				$ 233
Miami Beach EDITION Hotel
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of property		230
Assets, sold	38				38
Liabilities, sold	8				8
Miami Beach EDITION Hotel | Depreciation, amortization and other | Other unallocated corporate
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of long-lived assets	6
New York City EDITION Hotel
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of property	343
New York City EDITION Hotel | Depreciation, amortization and other | Other unallocated corporate
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of long-lived assets		$ 6
North American, plot of land | North American Limited-Service Segment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Current assets of dispositions	47				47
Current liabilities of dispositions	$ 1				$ 1