Schedule III - Real Estate and Accumulated Depreciation (Details 1) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Beginning Balance, Total Property	$ 3,993,427	$ 3,907,010	$ 3,633,993
Retirement/dispositions
Ending Balance, Total Property	4,359,993	3,993,427	3,907,010
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Beginning Balance, Accumulated Depreciation	1,025,831	933,220	843,816
Retirement/dispositions
Ending Balance, Accumulated Depreciation	1,121,102	1,025,831	933,220
Real Estate [Member]
Additions during the period
Total Property	384,762	112,591	322,616
Retirement/dispositions
TOTAL PROPERTY	(105,487)	(132,665)	(123,639)
Ending Balance, Total Property	4,272,083
Additions during the period
Accumulated Depreciation	9,285	4,175	4,206
Retirement/dispositions
Accumulated Depreciation	(79,659)	(69,102)	(50,683)
Ending Balance, Accumulated Depreciation	1,115,695
Other improvements [Member]
Additions during the period
Total Property	71,666	74,317	59,442
Additions during the period
Accumulated Depreciation	165,367	157,385	135,807
Land Held for Development [Member]
Additions during the period
Total Property	0	4,525	0
Retirement/dispositions
TOTAL PROPERTY	0	0	0
Additions during the period
Accumulated Depreciation	278	153	74
Retirement/dispositions
Accumulated Depreciation		0	0
Construction in Progress [Member]
Additions during the period
Total Property	15,625	27,649	14,598
Retirement/dispositions
Ending Balance, Total Property	48,731
Additions during the period
Accumulated Depreciation	0	$ 0	$ 0
Retirement/dispositions
Ending Balance, Accumulated Depreciation