Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Taxes [Line Items]
Number of subsequent years we may not able to qualify as REIT if failed to qualify for taxation as a REIT in any taxable year	4 years
Income tax provision	$ (220)	$ 30	$ 150
Net operating loss carry back period	5 years
Percentage of limitation on net operating losses of annual income	80.00%
Valuation allowance	$ 19	13
Net increase in valuation allowance	6
Total deferred tax assets, net of valuation allowance	$ 185	$ 38
Statutory federal income tax rate	21.00%	21.00%
Cash paid for income taxes, net of refunds received		$ 93	82
Decrease to unrecognized tax benefits	$ 4
Recognized material interest or penalties	0	$ 0	0
Other Assets | U.S. Federal
Income Taxes [Line Items]
Income taxes receivable	$ 57
Lower Limit
Income Taxes [Line Items]
Open tax year by major tax jurisdiction	2017
Upper Limit
Income Taxes [Line Items]
Open tax year by major tax jurisdiction	2020
Long Term Capital Gain
Income Taxes [Line Items]
Income tax provision			$ 77
Domestic | Lower Limit
Income Taxes [Line Items]
Open tax year by major tax jurisdiction	2017
Domestic | Upper Limit
Income Taxes [Line Items]
Open tax year by major tax jurisdiction	2019
Domestic | AOCI Foreign Exchange Net loss
Income Taxes [Line Items]
Valuation allowance	$ 5
Domestic | Capital Loss Carryover
Income Taxes [Line Items]
Valuation allowance	9
Foreign Tax Authority | Net Operating Loss and Capital Loss Carryover
Income Taxes [Line Items]
Valuation allowance	$ 5
Lower Limit
Income Taxes [Line Items]
Percentage of annual taxable income Host Inc is required to distribute	90.00%