Commitments and Contingencies - Guarantees (Details) € in Millions, SGD in Millions, $ in Millions	6 Months Ended
	Jun. 30, 2016 SGD	Jun. 30, 2016 USD ($)	Jun. 30, 2016 EUR (€)	Dec. 30, 2011 USD ($)	Sep. 09, 2005 EUR (€)
Primary Obligor
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings		$ 217
Recorded Liability for Guarantees		58
Primary Obligor | Debt service
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings		113
Recorded Liability for Guarantees		21
Primary Obligor | Debt service | New York City EDITION Hotel
Commitments and Contingencies Disclosure [Line Items]
Guarantor obligations, term	2 years
Guarantor obligations, extended term	3 years
Primary Obligor | Operating profit
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings		96
Recorded Liability for Guarantees		36
Primary Obligor | Other
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings		8
Recorded Liability for Guarantees		1
Primary Obligor | Not Yet In Effect Condition | Debt service
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings		11
Primary Obligor | Not Yet In Effect Condition | Debt service | New York City EDITION Hotel
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings		315
Primary Obligor | Not Yet In Effect Condition | Operating profit
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings		44
Primary Obligor | Not Yet In Effect Condition | Other
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings		1
Secondarily Liable
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings		53
Secondarily Liable | MVW Spin-off
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings	SGD 6	4
Guarantee obligations, carrying value		1
Secondarily Liable | Lease Obligations and Debt Securities Payable
Commitments and Contingencies Disclosure [Line Items]
Guarantee obligations, carrying value		3
Secondarily Liable | Debt Securities Payable
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings		15
Secondarily Liable | Debt Securities Payable | Sunrise Senior Living Inc
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings		3
Secondarily Liable | Debt Securities Payable | CNL Retirement Properties Inc
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings		12
Secondarily Liable | Property Lease Guarantee | Sunrise Senior Living Inc
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings		38
Guarantee obligations, cash collateralized				$ 1
Collateral for continuing lease obligation contingency, future minimum annual payments due from 2014 until 2018				1
Secondarily Liable | Property Lease Guarantee | Sunrise Senior Living Inc | Key Bank | Letter of Credit
Commitments and Contingencies Disclosure [Line Items]
Letter of credit provided by Sunrise, amount available				$ 85
Letter of credit provided by Sunrise, amount available at period end		49
Secondarily Liable | Property Lease Guarantee | Renaissance Hotel Group N.V.
Commitments and Contingencies Disclosure [Line Items]
Guarantee obligations, cash collateralized		2	€ 2		€ 35
Annual rent payments, approximately		4
Remaining rent payments, approximately		17
Secondarily Liable | Lease is Terminated by End of 2019 | Property Lease Guarantee | ExecuStay
Commitments and Contingencies Disclosure [Line Items]
Maximum Potential Amount of Future Fundings		6
Other noncurrent liabilities | Primary Obligor
Commitments and Contingencies Disclosure [Line Items]
Recorded Liability for Guarantees		$ 58
Minimum
Commitments and Contingencies Disclosure [Line Items]
Funding guarantees, minimum term	4 years
Maximum
Commitments and Contingencies Disclosure [Line Items]
Funding guarantees, minimum term	10 years