Schedule III - Real Estate and Accumulated Depreciation - Accumulated Depreciation Rollforward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
SEC Schedule III, Reconciliation of Carrying Amount of Real Estate Investments
Beginning balance	$ 1,368,613	$ 1,357,258	$ 1,191,218
Improvements	3,664	11,250	18,587
(Write-off) write-up of assets damaged by hurricane (Note 4)	(3,170)	105	(4,633)
Write-off of fully depreciated assets	(18)	0	0
Additions	0	0	152,086
Ending balance	1,369,089	1,368,613	1,357,258
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation
Beginning balance	78,078	47,221	18,506
Depreciation expense	31,900	30,857	28,715
Write-off of fully depreciated assets	(18)	0	0
Ending balance	$ 109,960	$ 78,078	$ 47,221