Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2018 USD ($) Property Entity Contract GroundLease	Dec. 31, 2017 USD ($) Property	Dec. 31, 2016 USD ($)	Jan. 01, 2018 USD ($)
Significant Accounting Policies [Line Items]
Number of impaired assets | Property	4	1
Impairment charges	$ 260,000,000	$ 43,000,000	$ 0
Advances to and investments in affiliates	$ 48,000,000	327,000,000
Percentage of property revenue allocated for renewal and replacement capital expenditures	5.00%
Number of majority-owned partnerships that have third-party, non-controlling ownership interests that have been consolidated | Entity	3
Non-redeemable non-controlling interests—other consolidated partnerships	$ 72,000,000	29,000,000
Net income attributable to non-controlling interests	52,000,000
Net income	12,000,000	7,000,000	9,000,000
Other-than-temporary impairment	$ 0	0	0
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	$ (13,000,000)	$ (14,000,000)	(17,000,000)
Stock-based employee compensation plans | Contract	2
Number of ground leases | GroundLease	25
Atlanta Marriott Marquis
Significant Accounting Policies [Line Items]
Environmental contingent liabilities	$ 400,000
Minimum
Significant Accounting Policies [Line Items]
Percentage of property revenue allocated for renewal and replacement capital expenditures	4.00%
Maximum
Significant Accounting Policies [Line Items]
Percentage of property revenue allocated for renewal and replacement capital expenditures	5.00%
Maximum | Atlanta Marriott Marquis
Significant Accounting Policies [Line Items]
Environmental contingent liabilities	$ 5,000,000
Accounting Standards Update 2016-02
Significant Accounting Policies [Line Items]
Percentage of annual operating lease payments	85.00%
Accounting Standards Update 2016-02 | Asset | Minimum
Significant Accounting Policies [Line Items]
Adjustment applied due to new accounting principle in period of adoption	$ 500,000,000
Accounting Standards Update 2016-02 | Asset | Maximum
Significant Accounting Policies [Line Items]
Adjustment applied due to new accounting principle in period of adoption	600,000,000
Accounting Standards Update 2016-02 | Liability | Minimum
Significant Accounting Policies [Line Items]
Adjustment applied due to new accounting principle in period of adoption	500,000,000
Accounting Standards Update 2016-02 | Liability | Maximum
Significant Accounting Policies [Line Items]
Adjustment applied due to new accounting principle in period of adoption	$ 600,000,000
ASU No. 2014-09
Significant Accounting Policies [Line Items]
Adoption of revenue recognition, description	We adopted these standards using a modified retrospective approach with a cumulative effect recognized in our equity balance on the date of adoption and no restatements of prior period amounts. When applying the new standard for the cumulative effect, we elected to apply the new standard only to contracts that were not considered completed as of the date of adoption.
Decrease in total liabilities				$ 4,500,000
Increase in total equity				$ 4,500,000
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
Significant Accounting Policies [Line Items]
Gain on foreign currency forward contracts	$ 23,000,000
Net loss related to sale of assets, previously recognized in foreign currency translation and other comprehensive income (loss) of unconsolidated affiliates, reclassified	$ (36,000,000)
HOST HOTELS & RESORTS L.P.
Significant Accounting Policies [Line Items]
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
Net loss related to sale of assets, previously recognized in foreign currency translation and other comprehensive income (loss) of unconsolidated affiliates, reclassified	$ (13,000,000)	$ (14,000,000)	$ (17,000,000)
JW Marriott Mexico City
Significant Accounting Policies [Line Items]
Non-redeemable non-controlling interests—other consolidated partnerships	$ 66,000,000
Hilton Melbourne South Wharf
Significant Accounting Policies [Line Items]
Net loss related to sale of assets, previously recognized in foreign currency translation and other comprehensive income (loss) of unconsolidated affiliates, reclassified		$ (14,000,000)
Property, Plant and Equipment, Other Types
Significant Accounting Policies [Line Items]
Estimated useful lives	3 years
Houston Airport Marriott at George Bush Intercontinental | Variable Interest Entities
Significant Accounting Policies [Line Items]
Total assets of VIE	$ 48,000,000
Liabilities of VIE	$ 4,000,000
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	$ (6,000,000)
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]
Percentage of the common OP units	99.00%