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Summary of Significant Accounting Policies - Additional Information (Detail) $ in Millions		12 Months Ended
	Jan. 01, 2019 USD ($)	Dec. 31, 2019 USD ($) Property Entity	Dec. 31, 2018 USD ($) Property	Dec. 31, 2017 USD ($) Property
Significant Accounting Policies [Line Items]
Total assets of VIE		$ 12,305	$ 12,090
Liabilities of VIE		4,838	4,396
Advances to and investments in affiliates		$ 56	$ 48
Percentage of property revenue allocated for renewal and replacement capital expenditures		5.00%
Number of impaired assets \| Property		1	4	1
Impairment charges		$ 14	$ 260	$ 43
Number of majority-owned partnerships that have third-party, non-controlling ownership interests that have been consolidated \| Entity		2
Non-redeemable non-controlling interests-other consolidated partnerships		$ 6	72
Net income attributable to non-controlling interests		2	52
Net income		$ 10	12	7
Percentage greater than threshold of income tax examination minimum likelihood of tax benefits being realized upon settlement		50.00%
Net loss related to sale of assets, previously recognized in foreign currency translation and other comprehensive income (loss) of unconsolidated affiliates, reclassified		$ (4)	(13)	$ (14)
Right-of-use assets		595
Lease liabilities		$ 606
ASU 2016-02
Significant Accounting Policies [Line Items]
Lease liabilities	$ 628
ASU 2016-02 \| Asset
Significant Accounting Policies [Line Items]
Right-of-use assets	619
ASU 2016-02 \| Rent Liability
Significant Accounting Policies [Line Items]
Reduction of the rent liability due to adoption	$ 9
RSU Awards \| Vesting over one-year Period
Significant Accounting Policies [Line Items]
Equity award vesting period		1 year
RSU Awards \| Vesting over two-year Period
Significant Accounting Policies [Line Items]
Equity award vesting period		2 years
RSU Awards \| Vesting over three-year Period
Significant Accounting Policies [Line Items]
Equity award vesting period		3 years
European Joint Venture and JW Marriott Hotel Mexico City \| Reclassification out of Accumulated Other Comprehensive Income
Significant Accounting Policies [Line Items]
Gain on foreign currency forward contracts			23
Net loss related to sale of assets, previously recognized in foreign currency translation and other comprehensive income (loss) of unconsolidated affiliates, reclassified			(36)
JW Marriott Mexico City
Significant Accounting Policies [Line Items]
Non-redeemable non-controlling interests-other consolidated partnerships			66
Property, Plant and Equipment, Other Types
Significant Accounting Policies [Line Items]
Estimated useful lives		3 years
HOST HOTELS & RESORTS L.P.
Significant Accounting Policies [Line Items]
Total assets of VIE		$ 12,305	12,090
Liabilities of VIE		$ 4,838	$ 4,396
OP units conversion basis		one OP unit may be exchanged for 1.021494 shares of Host Inc. common stock) valued at the market price of Host Inc.
Shares issuable upon conversion of one OP unit		1.021494	1.021494	1.021494
Net loss related to sale of assets, previously recognized in foreign currency translation and other comprehensive income (loss) of unconsolidated affiliates, reclassified		$ (4)	$ (13)	$ (14)
Right-of-use assets		595
Lease liabilities		606
Houston Airport Marriott at George Bush Intercontinental \| Variable Interest Entities
Significant Accounting Policies [Line Items]
Total assets of VIE		65
Liabilities of VIE		$ 26
Houston Airport Marriott at George Bush Intercontinental \| General Partner
Significant Accounting Policies [Line Items]
General partner and limited partner interest		85.00%
Philadelphia Marriott Downtown \| Variable Interest Entities Not Primary Beneficiary
Significant Accounting Policies [Line Items]
Advances to and investments in affiliates		$ (6)
Philadelphia Marriott Downtown \| Limited Partnership Interests Of Parent Company Ownership
Significant Accounting Policies [Line Items]
General partner and limited partner interest		11.00%
Host L.P.
Significant Accounting Policies [Line Items]
Investment ownership percentage		99.00%