Consolidated Statements of Income - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
NET SALES	$ 1,834,063,697	$ 1,794,872,578	$ 1,678,924,756
COST OF GOODS SOLD	1,143,597,005	1,100,344,312	1,010,472,512
Gross profit	690,466,692	694,528,266	668,452,244
OPERATING EXPENSES:
Engineering, research and development	107,134,862	99,726,438	94,238,032
Selling, general and administrative	75,206,283	71,443,476	62,471,277
Total operating expenses	182,341,145	171,169,914	156,709,309
Income from operations	508,125,547	523,358,352	511,742,935
OTHER INCOME:
Investment income	11,262,385	9,442,387	4,787,128
Other, net	2,659,015	(1,004,035)	(5,969,290)
Total other income (expense)	13,921,400	8,438,352	(1,182,162)
Income before provision for income taxes	522,046,947	531,796,704	510,560,773
PROVISION FOR INCOME TAXES	84,163,850	125,004,782	162,969,497
NET INCOME	$ 437,883,097	$ 406,791,922	$ 347,591,276
EARNINGS PER SHARE:
Basic (in dollars per share)	$ 1.64	$ 1.42	$ 1.21
Diluted (in dollars per share)	1.62	1.41	1.19
Cash Dividends Declared per Share (in dollars per share)	$ 0.440	$ 0.390	$ 0.355