CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues:
Rental income	$ 124,498,400	$ 188,019,112	$ 192,088,348
Tenant reimbursements and other	17,490,459	24,950,128	26,149,184
Total revenues	141,988,859	212,969,240	218,237,532
Expenses:
Operating, maintenance and management	38,512,239	58,347,903	57,832,187
Real estate taxes and insurance	24,230,326	35,114,937	36,507,827
Fees to affiliates	15,879,702	21,960,145	25,440,718
Depreciation and amortization	46,109,794	67,755,152	69,513,484
Interest expense	33,158,759	44,114,130	41,772,682
Loss on debt extinguishment	3,621,665	2,380,051	4,932,369
General and administrative expenses	6,269,238	6,732,330	7,817,916
Total expenses	167,781,723	236,404,648	243,817,183
Loss before other income (expense)	(25,792,864)	(23,435,408)	(25,579,651)
Equity in loss of unconsolidated joint venture	(3,339,202)	(663,896)	0
Gain on sales of real estate, net	118,215,618	96,573,171	0
Total other income (loss)	114,876,416	95,909,275	0
Net income (loss)	$ 89,083,552	$ 72,473,867	$ (25,579,651)
Income (loss) per common share — basic and diluted (in dollars per share)	$ 1.19	$ 0.96	$ (0.34)
Weighted average number of common shares outstanding — basic (in shares)	75,049,667	75,794,705	76,195,083
Weighted average number of common shares outstanding — diluted (in shares)	75,062,053	75,807,710	76,195,083