Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 318,757,352	$ 360,797,232	$ 347,563,621
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	96,568,443	99,112,019	104,739,900
Gain on disposal of assets	(70,736)	(488,750)	(311,510)
Loss on disposal of assets	28,424	230,933	162,553
Gain on sale of investments and equity method investment income	(392,040)	(1,379,538)	(3,163,164)
Loss on sale of investments and equity method investment losses	2,104,907	307,490	1,064,508
Deferred income taxes	(17,777,777)	(41,694,751)	(15,419,722)
Stock based compensation expense related to employee stock options, employee stock purchases and restricted stock	30,228,606	27,421,645	30,797,327
Change in operating assets and liabilities:
Accounts receivable	(26,698,846)	35,135,429	(49,290,457)
Inventories	(88,092,828)	(89,975,599)	22,725,798
Prepaid expenses and other	(28,788,331)	(20,241,994)	10,493,993
Accounts payable	37,423,488	7,266,309	(12,854,038)
Accrued liabilities	14,909,867	(14,322,863)	27,982,962
Net cash flows from operating activities	338,200,529	362,167,562	464,491,771
Activity in available-for-sale securities:
Sales proceeds	37,429,595	56,237,427	24,455,695
Maturities and calls	3,500,000	27,690,000	142,547,368
Purchases	(30,107,379)	(113,204,199)	(73,719,189)
Purchase of equity method investments	(33,830,274)	0	0
Plant and equipment additions	(146,433,123)	(68,835,047)	(51,706,541)
Proceeds from sale of plant and equipment	313,917	2,577,855	383,429
Acquisition of businesses, net of cash acquired	0	(12,071,546)	(11,216,927)
Increase in other assets	(3,611,244)	(5,501,445)	(4,327,398)
Net cash (used for) from investing activities	(172,738,508)	(113,106,955)	26,416,437
CASH FLOWS USED FOR FINANCING ACTIVITIES:
Proceeds from borrowings on Credit Agreement	0	0	75,000,000
Repayment of borrowings on Credit Agreement	0	0	(75,000,000)
Issuance of common stock from stock plan transactions	16,602,274	29,808,787	41,803,640
Cash dividends paid	(113,091,921)	(115,285,625)	(117,181,928)
Repurchases of common stock	(112,529,406)	(324,643,135)	(288,480,506)
Net cash used for financing activities	(209,019,053)	(410,119,973)	(363,858,794)
NET (DECREASE) INCREASE IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH	(43,557,032)	(161,059,366)	127,049,414
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH, Beginning of year	262,311,670	423,371,036	296,321,622
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH, End of year	$ 218,754,638	$ 262,311,670	$ 423,371,036