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, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share [Abstract]
NET INCOME		$ 216	$ 159	$ 320	$ 344
Less: Net income attributable to non-controlling interests		(4)	(4)	(10)	(10)
NET INCOME ATTRIBUTABLE TO REPORTING ENTITY		212	155	310	334
Assuming conversion of exchangeable senior debentures		7
Diluted income attributable to Host Inc.		$ 219	$ 155	$ 310	$ 334
Basic weighted average shares outstanding		753.9	755.4	755.0	755.1
Assuming weighted average shares for conversion of exchangeable senior debentures		31.2
Assuming distribution of common shares granted under the comprehensive stock plans, less shares assumed purchased at market		0.4	0.5	0.4	0.5
Diluted weighted average shares outstanding	[1]	785.5	755.9	755.4	755.6
Basic earnings per common share		$ 0.28	$ 0.21	$ 0.41	$ 0.44
Diluted earnings per common share		$ 0.28	$ 0.21	$ 0.41	$ 0.44

[1] There were approximately 31 million potentially dilutive shares for the year-to-date period ended June 30, 2015, and approximately 30 million potentially dilutive units for both the quarter and year-to-date periods ended June 30, 2014, related to our exchangeable senior debentures, which shares were not included in the computation of diluted earnings per share because to do so would have been anti-dilutive for the period.