Host Inc. Earnings (Loss) Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share [Abstract]
NET LOSS	$ (61)	$ (356)	$ (214)	$ (359)
Less: Net loss attributable to non-controlling interests	1	4	2	4
NET LOSS ATTRIBUTABLE TO HOST HOTELS & RESORTS, INC.	$ (60)	$ (352)	$ (212)	$ (355)
Basic weighted average shares outstanding	707.6	705.1	706.6	706.7
Diluted weighted average shares/units outstanding	707.6	705.1	706.6	706.7
Basic loss per common share	$ (0.09)	$ (0.50)	$ (0.30)	$ (0.50)
Diluted loss per common share	$ (0.09)	$ (0.50)	$ (0.30)	$ (0.50)