Dispositions - Additional Information (Detail) $ in Millions	3 Months Ended
Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($) Hotel
Discontinued Operations And Disposal Groups [Abstract]
Gross proceeds on sale of hotel portfolio properties	$ 69	$ 379
Net gain on selling cost of hotel portfolio properties	$ 31	$ 89
Number of hotel portfolio properties sold \| Hotel		12
Reclassification of currency translation adjustment from accumulated other comprehensive loss to earnings on disposition of hotel portfolio properties		$ 31

Amount before tax of gain (loss) recognized on the sale or disposal of a disposal group. Excludes discontinued operations.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=109226348&loc=d3e2443-110228

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration