Supplemental Information to Statements of Cash Flows (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Non Cash Investing and Financing Information [Line Items]
Interest paid, net of capitalized interest	$ 18,729	$ 17,871
Income taxes paid	99	540
Distributions payable on shares/units	31,429		$ 31,823
Issuance of common shares for Board of Trustees compensation	662	503
Accrued additions and improvements to hotel properties	1,566	514
Write-off of deferred financing costs	0	776
Common Shares [Member]
Non Cash Investing and Financing Information [Line Items]
Distributions payable on shares/units	27,987	28,066
Preferred Shares [Member]
Non Cash Investing and Financing Information [Line Items]
Distributions payable on shares/units	$ 3,442	$ 3,442