Contingencies - Guarantees (Details) In Millions, unless otherwise specified	6 Months Ended															4 Months Ended												6 Months Ended
	Jun. 30, 2014	Jun. 30, 2014 Lease Obligations and Debt Securities Payable USD ($)	Jun. 30, 2014 Property Lease Guarantee ExecuStay USD ($)	Jun. 30, 2014 Primary Obligor USD ($)	Jun. 30, 2014 Primary Obligor Debt service USD ($)	Jun. 30, 2014 Primary Obligor Operating profit USD ($)	Jun. 30, 2014 Primary Obligor Other guarantees USD ($)	Jun. 30, 2014 Primary Obligor Not Yet In Effect Condition Debt service USD ($)	Jun. 30, 2014 Primary Obligor Not Yet In Effect Condition Operating profit USD ($)	Jun. 30, 2014 Primary Obligor Not Yet In Effect Condition Other guarantees USD ($)	Jun. 30, 2014 Secondarily Liable USD ($)	Jun. 30, 2014 Secondarily Liable MVW Spin-off USD ($)	Jun. 30, 2014 Secondarily Liable MVW Spin-off Expiration in 2017 USD ($)	Jun. 30, 2014 Secondarily Liable MVW Spin-off Expiration in 2022 USD ($)	Jun. 30, 2014 Secondarily Liable MVW Spin-off Expiration in 2022 SGD	Dec. 30, 2011 Secondarily Liable Property Lease Guarantee Sunrise Senior Living Inc USD ($)	Jun. 30, 2014 Secondarily Liable Property Lease Guarantee Sunrise Senior Living Inc USD ($)	Jun. 30, 2014 Secondarily Liable Property Lease Guarantee Sunrise Senior Living Inc Key Bank Letter of Credit USD ($)	Dec. 30, 2011 Secondarily Liable Property Lease Guarantee Sunrise Senior Living Inc Key Bank Letter of Credit USD ($)	Jun. 30, 2014 Secondarily Liable Property Lease Guarantee Renaissance Hotel Group N.V. USD ($)	Jun. 30, 2014 Secondarily Liable Property Lease Guarantee Renaissance Hotel Group N.V. EUR (€)	Sep. 09, 2005 Secondarily Liable Property Lease Guarantee Renaissance Hotel Group N.V. EUR (€)	Jun. 30, 2014 Secondarily Liable Debt Securities Payable USD ($)	Jun. 30, 2014 Secondarily Liable Debt Securities Payable Sunrise Senior Living Inc USD ($)	Jun. 30, 2014 Secondarily Liable Debt Securities Payable CNL Retirement Properties Inc USD ($)	Jun. 30, 2014 Secondarily Liable Debt Securities Payable Five Star Senior Living USD ($)	Jun. 30, 2014 Secondarily Liable Lease is Terminated by End of 2019 Property Lease Guarantee ExecuStay USD ($)	Jun. 30, 2014 New York City EDITION Hotel Primary Obligor Other guarantees USD ($)
Commitments and Contingencies Disclosure [Line Items]
Funding guarantees, minimum term	4 years
Funding guarantees, maximum term	10 years
Liability for guarantees				$ 49	$ 12	$ 36	$ 1
Maximum potential amount of future fundings				175	68	91	16	20	11	1	92	14	3	11	13		67						25	4	20	1	6	315
Guarantor obligations, term																												2 years
Guarantor obligations, extended term																												3 years
Guarantee obligations, carrying value		3	1									2
Length of operating lease extension																5 years
Cash collateralized for lease guarantee for period from 2014 until 2018																1
Letter of credit provided by Sunrise, amount available for five years																			85
Letter of credit provided by Sunrise, amount available at period end																		78
Collateral for continuing lease obligation contingency, future minimum annual payments due from 2014 until 2018																1
Annual rent payments, approximately																				6
Remaining rent payments, approximately																				32
Guarantee obligations, cash collateralized																				$ 4	€ 3	€ 35