Earnings (Loss) Per Common Share (Unit) - Additional Information (Detail) - HOST HOTELS & RESORTS, INC. shares in Millions	Jun. 30, 2021 shares
Shares Subject To Mandatory Redemption By Settlement Terms [Line Items]
Common units outstanding	7.2
Number of common shares that would be outstanding if OP units were converted	7.4

The number of units or equivalent units outstanding for all classes.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 5
-Subparagraph (SAB TOPIC 4.F)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187171-122770

Name:	us-gaap_UnitsOfPartnershipInterestAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant