Acquisitions and Dispositions - Acquisitions (Detail) $ / shares in Units, ZAR in Millions, CAD in Millions, BRL in Millions, $ in Millions		3 Months Ended
	Nov. 15, 2015 $ / shares shares	Sep. 30, 2015 CAD	Sep. 30, 2015 USD ($)	Jun. 30, 2015 CAD hotel_and_resort room	Jun. 30, 2015 USD ($) hotel_and_resort room	Dec. 31, 2014 BRL	Dec. 31, 2014 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2014 ZAR	Dec. 31, 2015 USD ($) $ / shares	Sep. 30, 2015 USD ($)
Business Acquisition [Line Items]
Common stock, par value (in USD per share) | $ / shares	$ 0.01									$ 0.01
Goodwill | $							$ 894			$ 943
Starwood Hotels & Resorts
Business Acquisition [Line Items]
Cash payments to acquire businesses, gross per share | $ / shares	$ 2.00
Starwood Hotels & Resorts | Common Stock
Business Acquisition [Line Items]
Business acquisition, equity interest issued, number of shares | shares	0.920
Delta Hotels and Resorts
Business Acquisition [Line Items]
Cash consideration paid				CAD 170	$ 134
Working capital acquired				2	2
Acquisition amount				CAD 172	$ 136
Recognized identifiable assets and liabilities acquired		CAD 161									$ 127
Finite-lived intangible assets acquired		22	$ 17
Indefinite-lived intangible assets		115									91
Goodwill		24									19
Recognized identifiable tangible assets acquired		CAD 11									$ 9
Number of open hotels and resorts acquired				37	37
Number of rooms acquired | room				9,590	9,590
Number of managed hotels and resorts acquired				27	27
Number of managed hotels and resorts acquired, 30 year management agreement				13	13
Number of hotels and resorts acquired				10	10
Number of hotels and resorts under development acquired				5	5
Number of hotels and resorts under development acquired, 30 year management agreement				1	1
Protea Hospitality Holdings
Business Acquisition [Line Items]
Cash consideration paid								$ 195	ZAR 2,059
Protea Hospitality Holdings | Trademarks and Trade Names
Business Acquisition [Line Items]
Business acquisition, adjustment, intangible assets | $					$ 12
Protea Hospitality Holdings | Contractual Assets
Business Acquisition [Line Items]
Business acquisition, adjustment, intangible assets | $					$ 40
Brazil, Property Under Construction
Business Acquisition [Line Items]
Cash consideration paid						BRL 74	$ 31