Basis of Presentation and Organization (Narrative) (Details) $ in Thousands	1 Months Ended	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2020 USD ($)	Sep. 30, 2020 USD ($)	Mar. 31, 2020 USD ($) hotel	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) segment	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)	Jul. 01, 2020	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Dec. 31, 2018 USD ($)
Restructuring Cost and Reserve [Line Items]
Impairment of real estate		$ 0		$ 0	$ 48,738	$ 0
Number of reportable segments | segment					4
Total Equity	$ 3,713,662	3,713,662		3,380,056	$ 3,713,662	3,380,056	$ 3,332,988		$ 3,739,703	$ 3,351,767	$ 3,238,126
Accounting standards update					us-gaap:AccountingStandardsUpdate201613Member		us-gaap:AccountingStandardsUpdate201613Member
Decrease in retained earnings	(3,713,287)	(3,713,287)			$ (3,713,287)		$ (3,148,133)
Corporate Restructuring
Restructuring Cost and Reserve [Line Items]
Assets held for sale							2,000,000
Restructuring charges					2,058
Corporate Restructuring | Minimum
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost remaining	200	200			200
Corporate Restructuring | Maximum
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost remaining	700	700			700
Corporate Restructuring | One-time Termination Benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges					2,100		34,300
Accumulated Deficit
Restructuring Cost and Reserve [Line Items]
Total Equity	$ (65,910)	$ (65,910)		(45,285)	$ (65,910)	(45,285)	(46,385)		$ (205,621)	$ (75,043)	$ (120,341)
Cumulative Effect, Period of Adoption, Adjustment
Restructuring Cost and Reserve [Line Items]
Total Equity							(18)
Cumulative Effect, Period of Adoption, Adjustment | Accumulated Deficit
Restructuring Cost and Reserve [Line Items]
Total Equity							$ (18)
COVID-19 | The Woodlands Resort And Conference Center
Restructuring Cost and Reserve [Line Items]
Operating percentage of capacity	54.00%	54.00%			54.00%
COVID-19 | Embassy Suites, Hughes Landing
Restructuring Cost and Reserve [Line Items]
Operating percentage of capacity									100.00%
COVID-19 | Westin at The Woodlands
Restructuring Cost and Reserve [Line Items]
Operating percentage of capacity								100.00%
SEC Schedule, 12-09, Allowance, Loan and Lease Loss | COVID-19
Restructuring Cost and Reserve [Line Items]
Provision for doubtful accounts		$ 9,700			$ 16,900
SEC Schedule, 12-09, Reserve, Legal | COVID-19
Restructuring Cost and Reserve [Line Items]
Provision for doubtful accounts		1,700			5,900
Number of hotels | hotel			3
Outlet Collection, Riverwalk
Restructuring Cost and Reserve [Line Items]
Impairment of real estate		$ 0	$ 48,700	$ 0	$ 48,738	$ 0
Outlet Collection, Riverwalk | COVID-19
Restructuring Cost and Reserve [Line Items]
Impairment of real estate			$ 48,700
Chief Executive Officer
Restructuring Cost and Reserve [Line Items]
Salary and benefit related expense	$ 1,400