Acquisitions and Dispositions - Acquisitions and Planned Acquisitions (Details) £ / shares in Units, £ in Millions, $ in Millions	3 Months Ended
	Dec. 31, 2019 USD ($) hotel	Dec. 31, 2019 GBP (£) hotel £ / shares	Mar. 31, 2019 USD ($) joint_venture
Subsequent Event | Elegant Hotels Group plc
Schedule of Asset Acquisition [Line Items]
Number of hotels acquired | hotel	7	7
Amount per share each shareholder is entitled to receive (in gbp per share) | £ / shares		£ 1.10
Offer for issued and to be issued share capital	$ 130.1	£ 100.8
Enterprise value	199.0
AC Hotels by Marriott
Schedule of Asset Acquisition [Line Items]
Number of joint ventures acquired | joint_venture			2
AC Hotels by Marriott | Management and Franchise Contracts
Schedule of Asset Acquisition [Line Items]
Finite lived intangible assets term			24 years
Finite lived intangible assets acquired			$ 34.0
AC Hotels by Marriott | Brand Assets
Schedule of Asset Acquisition [Line Items]
Indefinite lived intangible assets acquired			$ 156.0
W New York - Union Square | Subsequent Event
Schedule of Asset Acquisition [Line Items]
Property purchased	$ 206.0