CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities
Net income	$ 13,726,071	$ 11,989,274
Adjustments to reconcile net income to net cash provided by operating activities:
Income from discontinued operations		(1,115,825)
Gain on sale of discontinued operations	(3,621,170)	0
Depreciation and amortization	7,207,647	7,034,234
Deferred income tax benefit	(239,848)	(365,019)
Unrealized (gain) loss on net put/call option	(56,000)	256,000
Compensation expense relating to stock and stock option grants	1,192,224	850,136
Loss (gain) on asset dispositions and impairments, net	(445,041)	56,774
Foreign currency transaction adjustment	(104,991)	2,593
Profit-sharing and equity in earnings of OC-BVI	(60,965)	(2,452,355)
Distribution of earnings from OC-BVI	742,350	2,651,250
Change in:
Accounts receivable and costs and estimated earnings in excess of billings	(414,006)	(9,512,730)
Inventory	(1,357,032)	(1,131,409)
Prepaid expenses and other assets	(171,841)	(800,540)
Accounts payable, accrued expenses and other current liabilities, and billings in excess of costs and estimated earnings	(1,193,740)	528,014
Net cash provided by operating activities - continuing operations	15,203,658	7,990,397
Net cash provided by operating activities - discontinued operations		1,055,949
Net cash provided by operating activities	15,203,658	9,046,346
Cash flows from investing activities
Additions to property, plant and equipment and construction in progress	(3,525,122)	(16,202,520)
Proceeds from asset dispositions	453,480	51,590
Proceeds from sale of discontinued operations, net of cash provided	6,971,234
Acquisition of PERC, net of cash acquired	(3,147,438)
Collections on loans receivable	734,980	1,400,448
Payment for land and right of way held for development	(1,499)	(2,655,349)
Net cash provided by (used in) investing activities	1,485,635	(17,405,831)
Cash flows from financing activities
Dividends paid to common shareholders	(5,103,801)	(5,081,107)
Dividends paid to preferred shareholders	(12,026)	(14,535)
Repurchase of redeemable preferred stock	(24,096)	(17,338)
Proceeds received from exercise of stock options	15,822	12,976
Issuance of note payable to related party		784,000
Payments made on note payable to related party		(1,470,000)
Net cash used in financing activities	(5,124,101)	(5,786,004)
Net increase (decrease) in cash and cash equivalents	11,565,192	(14,145,489)
Cash and cash equivalents at beginning of period	31,337,477	45,482,966
Cash and cash equivalents at end of period	$ 42,902,669	$ 31,337,477