Summary of Significant Accounting Policies - Additional Information (Detail)	1 Months Ended		12 Months Ended
	Feb. 28, 2022 USD ($)	Apr. 30, 2020 Hotel	Dec. 31, 2021 USD ($) Entity	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Significant Accounting Policies [Line Items]
Draws on credit facility			$ 0	$ 2,245,000,000	$ 0
Repayment of credit facility			(800,000,000)	(762,000,000)	(56,000,000)
Total assets of VIE			12,352,000,000	12,890,000,000
Liabilities of VIE			5,780,000,000	6,456,000,000
Advances to and investments in affiliates			$ 42,000,000	21,000,000
Percentage of property revenue allocated for renewal and replacement capital expenditures			5.00%
Impairment charges			$ 92,000,000	0	14,000,000
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			$ 5,000,000	5,000,000
Net income (loss) attributable to non-controlling interests			1,000,000	(1,000,000)	2,000,000
Net income (loss)			$ (1,000,000)	(8,000,000)	10,000,000
Percentage greater than threshold of income tax examination minimum likelihood of tax benefits being realized upon settlement			50.00%
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
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]
Draws on credit facility			$ 0	2,245,000,000	0
Repayment of credit facility			(800,000,000)	(762,000,000)	$ (56,000,000)
Total assets of VIE			12,352,000,000	12,890,000,000
Liabilities of VIE			$ 5,780,000,000	$ 6,456,000,000
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 common OP unit			1.021494	1.021494
Houston Airport Marriott at George Bush Intercontinental | Variable Interest Entities
Significant Accounting Policies [Line Items]
Total assets of VIE			$ 58,000,000
Liabilities of VIE			$ 26,000,000
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			$ (7,000,000)
Philadelphia Marriott Downtown | Limited Partner Interest
Significant Accounting Policies [Line Items]
General partner and limited partner interest			11.00%
Revolving Credit Facility
Significant Accounting Policies [Line Items]
Repayment of credit facility	$ (683,000,000)
COVID - 19
Significant Accounting Policies [Line Items]
Number of hotels suspends operations | Hotel		35
COVID - 19 | Revolving Credit Facility
Significant Accounting Policies [Line Items]
Draws on credit facility				$ 1,500,000,000
Repayment of credit facility			$ (800,000,000)
Host L.P.
Significant Accounting Policies [Line Items]
Investment ownership percentage			99.00%
Subsequent Event [Member] | Revolving Credit Facility
Significant Accounting Policies [Line Items]
Repayment of credit facility	(683,000,000)
Subsequent Event [Member] | COVID - 19 | Revolving Credit Facility
Significant Accounting Policies [Line Items]
Repayment of credit facility	$ (683,000,000)