Supplemental Information to Statements of Cash Flows (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Non Cash Investing and Financing Information [Line Items]
Interest paid, net of capitalized interest	$ 29,389	$ 24,690
Income taxes paid	2,288	594
Distributions payable on shares/units	31,647		$ 31,823
Issuance of common shares for Board of Trustees compensation	662	503
Accrued additions and improvements to hotel properties	593	1,400
Write off of fully depreciated building, furniture, fixtures and equipment	0	10,000
Write-off of deferred financing costs	0	776
Common Shares [Member]
Non Cash Investing and Financing Information [Line Items]
Distributions payable on shares/units	28,205	28,269
Preferred Shares [Member]
Non Cash Investing and Financing Information [Line Items]
Distributions payable on shares/units	$ 3,442	$ 3,442