Schedule III - Real Estate and Accumulated Depreciation - Changes in Accumulated Depreciation (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Balance, beginning of period	$ 2,385,287,743	$ 2,433,052,747	$ 2,278,291,645
Depreciation for year	260,533,557	293,667,298	368,919,387
Sales	(55,437,757)	(239,277,690)	(86,798,173)
Transfers to operating lease liabilities	(1,342,030)	0	0
Transfers to unconsolidated joint ventures	0	(11,634,554)	0
Assets held for sale	(32,642,081)	(17,527,267)	(19,699,746)
Adjustment for fully depreciated assets/other	(56,346,790)	(72,992,791)	(107,660,366)
Balance, end of period	$ 2,500,052,642	$ 2,385,287,743	$ 2,433,052,747