Hotel Management Agreements and Leases - Sonesta (Details) $ in Thousands	3 Months Ended		6 Months Ended			12 Months Ended	17 Months Ended
	Jun. 30, 2017 USD ($) hotel	Jun. 30, 2016 USD ($)	Dec. 31, 2017 USD ($)	Jun. 30, 2017 USD ($) hotel	Jun. 30, 2016 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)
Management Agreements and Leases [Line Items]
Capital improvements from leased facilities, funded				$ 62,204	$ 86,929
Sonesta agreements
Management Agreements and Leases [Line Items]
Procurement and construction supervision fees	$ 113	$ 581		$ 194	924
Hotel | Sonesta agreements
Management Agreements and Leases [Line Items]
Fixed minimum return as a percentage of invested capital				8.00%
Operating agreement annual rent and return				$ 97,134
Realized returns and rents	24,405	23,380		35,067	32,146
Related party transaction, management marketing and reservation system fees	7,558	6,995		13,287	12,295
Capital improvements from leased facilities, funded				$ 6,833
Percentage increase in minimum returns				8.00%
Forecast | Hotel | Sonesta agreements
Management Agreements and Leases [Line Items]
Capital improvements from leased facilities, funded			$ 18,618			$ 30,700
Sonesta Int'l Hotels Corp
Management Agreements and Leases [Line Items]
Due to related party, reimbursement of capital expenditures and other	$ 2,438	$ 6,207		$ 2,438	$ 6,207
Sonesta Int'l Hotels Corp | Full service hotel
Management Agreements and Leases [Line Items]
Number of real estate properties leased or managed | hotel	10			10
Sonesta Int'l Hotels Corp | Limited services hotel
Management Agreements and Leases [Line Items]
Number of real estate properties leased or managed | hotel	25			25
Various locations acquired for Sonesta conversion | Forecast | Hotel
Management Agreements and Leases [Line Items]
Capital improvements from leased facilities, funded						$ 54,000	$ 54,000