Asset acquisition and business combination.

No definition available.

Name:	hst_AssetAcquisitionAndBusinessCombinationLineItems
Namespace Prefix:	hst_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of consideration transferred in asset acquisition. Includes, but is not limited to, cash, liability incurred by acquirer, and equity interest issued by acquirer.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 50
-Section 30
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=123362884&loc=d3e9215-128498

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 50
-Section 55
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6829253&loc=SL6831962-166255

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 50
-Section 25
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=123385561&loc=d3e9135-128495

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 50
-Section 30
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=123362884&loc=d3e9212-128498

+ Details

Name:	us-gaap_AssetAcquisitionConsiderationTransferred
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The fair value of loans assumed in noncash investing or financing activities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=123431023&loc=d3e4313-108586

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=123431023&loc=d3e4304-108586

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=123431023&loc=d3e4332-108586

+ Details

Name:	us-gaap_LoansAssumed1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of debt that an Entity assumes in acquiring a business or in consideration for an asset received in a noncash (or part noncash) acquisition. Noncash is defined as transactions during a period that affect recognized assets or liabilities but that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=123431023&loc=d3e4304-108586

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=123431023&loc=d3e4313-108586

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=123431023&loc=d3e4332-108586

+ Details

Name:	us-gaap_NoncashOrPartNoncashAcquisitionDebtAssumed1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The number of units in a real estate property owned as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfUnitsInRealEstateProperty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

This element represents those amounts set aside for the repair and replacement of real or personal property in the foreseen future. Such amount may be funded from sales revenue (for example; timeshare sales) or operating revenues; in a lump sum or installments (such as monthly); as per internal policy (for example: hotel operators), as required by contractual agreement (for example: sales contract); or by the terms of debt agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.2,10)
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

+ Details

Name:	us-gaap_ReplacementReserveEscrow
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=hst_HyattRegencyAustinMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=hst_FourSeasonsResortOrlandoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=hst_KaanapaliGolfCoursesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=hst_BakersCayResortKeyLargoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=hst_DowntownHoustonHotelMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=hst_AlilaVentanaBigSurMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=hst_AlidaSavannahMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=hst_HotelVanZandtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MortgageLoansOnRealEstateLoanTypeAxis=us-gaap_ConventionalLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Acquisitions - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($) Room	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Asset Acquisition And Business Combination [Line Items]
Furniture, fixtures and equipment replacement fund	$ 144	$ 139	$ 176
Hyatt Regency Austin
Asset Acquisition And Business Combination [Line Items]
Number of rooms/apartment \| Room	448
Acquisition purchase price	$ 161
Four Seasons Resort Orlando at Walt DisneyWorld Resort
Asset Acquisition And Business Combination [Line Items]
Number of rooms/apartment \| Room	444
Acquisition purchase price	$ 610
Kaanapali Golf Courses
Asset Acquisition And Business Combination [Line Items]
Acquisition purchase price	$ 28
Bakers Cay Resort Key Largo Curio Collection by Hilton
Asset Acquisition And Business Combination [Line Items]
Number of rooms/apartment \| Room	200
Acquisition purchase price	$ 200
Downtown Houston Hotel
Asset Acquisition And Business Combination [Line Items]
Number of rooms/apartment \| Room	223
Acquisition purchase price	$ 65
Alila Ventana Big Sur
Asset Acquisition And Business Combination [Line Items]
Number of rooms/apartment \| Room	59
Acquisition purchase price	$ 150
Alida savannah
Asset Acquisition And Business Combination [Line Items]
Number of rooms/apartment \| Room	173
Acquisition purchase price	$ 103
Hotel Van Zandt Austin
Asset Acquisition And Business Combination [Line Items]
Number of rooms/apartment \| Room	319
Acquisition purchase price	$ 246
Furniture, fixtures and equipment replacement fund	4
Hotel Van Zandt Austin \| Mortgage Loan
Asset Acquisition And Business Combination [Line Items]
Mortgage loan	102
Fair value portion of mortgage loans	$ 105