Lease Incentives (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($) item
Lease Incentives
Non-contingent lease incentives	$ 2,552	$ 14,443
Non-contingent lease incentives, funding	387	1,272	$ 6,544
Total funding	387	1,272	6,544
Non-contingent lease incentives, Amortization	(385)	(1,733)	(1,590)
Contingent lease incentives, Amortization		(359)	(619)
Total amortization	(385)	(2,092)	(2,209)
Non-contingent lease incentives, Write off	(11,893)	(12,093)	(1,205)
Contingent lease incentives, Write off		(6,219)	(2,634)
Reclassification of Notes Receivable to Lease Incentives	200
Total Write off	$ (11,893)	$ (6,219)	$ (3,839)
Number of properties with lease incentives write-offs | item			2