Schedule III - Real Estate and Accumulated Depreciation Reconciliation (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Balance at beginning of the year	$ 6,228,954
Acquistion and development of rental properties during the year	617,018
Disposition of rental properties during the year	(577,457)
Other Deductions during the year	(2,206)
Balance at close of year	6,251,398
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Balance at beginning of the year	883,174
Depreciation during the year	169,072
Disposition of rental properties during the year	(62,992)
Balance at close of year	989,254
Public charter school properties [Member]
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Other Deductions during the year	$ (14,911)