Income Taxes - Reconciliation of income tax attributable to continuing operations for TRSs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes [Line Items]
TRS income tax provision	$ 1,507	$ 2,429	$ 989
TRS
Income Taxes [Line Items]
Tax (provision) benefit at U.S. statutory rates on TRS income subject to tax	(789)	327	1,277
State income tax, net of federal income tax benefit	(57)	13	57
Effect of permanent differences and other	5	(154)	207
Deferred tax impact of tax reform	0	0	(9,206)
Decrease (increase) in valuation allowance	841	(186)	7,665
TRS income tax provision	$ 0	$ 0	$ 0