Schedule III - Consolidated Real Estate and Accumulated Depreciation - Reconciliation of Accumulated Depreciation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Balance, beginning of year	$ 660,276	$ 556,851	$ 428,930
Depreciation expense	132,662	148,346	148,947
Impairment	(2,838)	(3,494)	0
Disposals	(95,088)	(41,427)	(21,026)
Balance, end of year	$ 695,012	$ 660,276	$ 556,851
Building | Minimum
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Life used for depreciation	20 years
Building | Maximum
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Life used for depreciation	35 years
Building Improvements | Minimum
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Life used for depreciation	10 years
Building Improvements | Maximum
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Life used for depreciation	35 years
Furniture and Fixtures | Minimum
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Life used for depreciation	5 years
Furniture and Fixtures | Maximum
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Life used for depreciation	10 years