Host Inc. Earnings (Loss) Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share [Abstract]
NET LOSS	$ (153)	$ (3)
Less: Net loss attributable to non-controlling interests	1
NET LOSS ATTRIBUTABLE TO HOST HOTELS & RESORTS, INC.	$ (152)	$ (3)
Basic weighted average shares outstanding	705.6	708.1
Diluted weighted average shares/units outstanding	705.6	708.1
Basic loss per common share	$ (0.22)
Diluted loss per common share	$ (0.22)