Commitments and Contingencies - Contingent Purchase Obligations (Details) $ in Millions	Mar. 31, 2018 USD ($)
Guarantor Obligations [Line Items]
Guarantee	$ 373
Guarantee, recorded liability	186
Sheraton Grand Chicago Hotel
Guarantor Obligations [Line Items]
Guarantee, recorded liability	57
Sheraton Grand Chicago Hotel \| Hotel and Leasehold
Guarantor Obligations [Line Items]
Guarantee	300
Sheraton Grand Chicago Hotel \| Land
Guarantor Obligations [Line Items]
Guarantee	$ 200

The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=82913245&loc=d3e12069-110248

+ Details

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Balance Type:	credit
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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=82913245&loc=d3e12069-110248

+ Details

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Period Type:	instant

- Details

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- Details

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- Details

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