Consolidated Statements of Income - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
NET SALES	$ 1,678,924,756	$ 1,543,617,706	$ 1,375,501,159
COST OF GOODS SOLD	1,010,472,512	939,841,654	836,611,464
Gross profit	668,452,244	603,776,052	538,889,695
OPERATING EXPENSES:
Engineering, research and development	94,238,032	88,392,919	84,175,738
Selling, general and administrative	62,471,277	56,616,694	55,879,783
Total operating expenses	156,709,309	145,009,613	140,055,521
Income from operations	511,742,935	458,766,439	398,834,174
OTHER INCOME:
Investment income	4,787,128	4,990,811	6,016,727
Other, net	(5,969,290)	(165,794)	10,475,589
Total other income	(1,182,162)	4,825,017	16,492,316
Income before provision for income taxes	510,560,773	463,591,456	415,326,490
PROVISION FOR INCOME TAXES	162,969,497	145,121,597	126,721,911
NET INCOME	$ 347,591,276	$ 318,469,859	$ 288,604,579
EARNINGS PER SHARE:
Basic (in dollars per share)	$ 1.21	$ 1.09	$ 0.99
Diluted (in dollars per share)	1.19	1.08	0.98
Cash Dividends Declared per Share (in dollars per share)	$ 0.355	$ 0.335	$ 0.31