CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities
Net income	$ 1,117,565	$ 3,249,605
Adjustments to reconcile net income to net cash provided by operating activities:
Unrealized (gain) loss on net put/call option	(131,000)	161,000
Net cash provided by operating activities - continuing operations	1,466,141	283,539
Net cash used in operating activities - discontinued operations	(380,001)	(572,188)
Net cash provided by (used in) operating activities	1,086,140	(288,649)
Cash flows from investing activities
Additions to property, plant and equipment and construction in progress	(292,803)	(516,331)
Proceeds from asset dispositions	41,500	450
Net cash used in investing activities	(251,303)	(9,015,881)
Cash flows from financing activities
Dividends paid to common shareholders	(1,288,726)	(1,280,993)
Dividends paid to preferred shareholders	(2,641)	(2,869)
Dividends paid to non-controlling interests	(649,880)
Repurchase of redeemable preferred stock	(7,513)	0
Principal repayments on long-term debt	(10,632)	(3,496)
Net cash used in financing activities	(1,959,392)	(1,287,358)
Net decrease in cash and cash equivalents	(1,124,555)	(10,591,888)
Cash and cash equivalents at beginning of period	43,794,150	42,071,083
Cash and cash equivalents at beginning of period - discontinued operations	154,130	831,586
Less: cash and cash equivalents at end of period - discontinued operations	(41,198)	(820,275)
Cash and cash equivalents at end of period	42,782,527	31,490,506
Interest paid in cash	2,740	2,526
Non-cash transactions:
Dividends declared but not paid	1,296,877	1,290,058
Transfers from (to) inventory to (from) property, plant and equipment and construction in progress	75,433	(71,719)
Transfers from construction in progress to property, plant and equipment	81,599	1,336,271
Right-of-use assets obtained in exchange for new operating lease liabilities	1,716,789	16,383
Purchase of equipment through issuance of long-term debt	58,220	122,292
Aerex
Cash flows from investing activities
Acquisition of noncontrolling interest in subsidiaries	$ 0	$ (8,500,000)