Summary of Unaudited Quarterly Results of Operations - Summary of Unaudited Quarterly Results of Operations (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Revenues and other income	$ 13,474,067	$ 13,839,947	$ 14,478,419	$ 15,152,158	$ 21,107,249	$ 25,341,629	$ 14,346,334	$ 17,664,598
Income (loss) from continuing operations	798,740	(1,160,017)	4,588,348	2,981,757	10,446,245	9,707,903	3,886,190	6,451,813
Net income (loss)	$ 798,740	$ (1,160,017)	$ 4,588,348	$ 2,981,757	$ 10,446,245	$ 9,707,903	$ 3,886,190	$ 6,451,813
Income (loss) from continuing operations, per BUC	$ 0.00	$ (0.03)	$ 0.06	$ 0.04	$ 0.16	$ 0.13	$ 0.05	$ 0.08
Net income (loss), basic and diluted, per BUC	$ 0.00	$ (0.03)	$ 0.06	$ 0.04	$ 0.16	$ 0.13	$ 0.05	$ 0.08	$ 0.07	$ 0.42