Consolidated Statements of Income (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Statement [Abstract]
NET SALES	$ 1,171,864,171	$ 1,099,559,521	$ 1,023,762,049
COST OF GOODS SOLD	741,131,269	726,740,962	662,181,714
Gross profit	430,732,902	372,818,559	361,580,335
OPERATING EXPENSES:
Engineering, research and development	76,495,051	85,003,602	81,634,158
Selling, general and administrative	49,496,038	48,359,725	48,578,252
Litigation Settlement	0	5,000,000	0
Total operating expenses	125,991,089	138,363,327	130,212,410
Income from operations	304,741,813	234,455,232	231,367,925
OTHER INCOME:
Investment income	6,724,717	5,307,180	4,165,809
Other, net	16,597,513	9,863,188	8,898,077
Total other income	23,322,230	15,170,368	13,063,886
Income before provision for income taxes	328,064,043	249,625,600	244,431,811
PROVISION FOR INCOME TAXES	105,134,094	81,038,760	79,763,583
NET INCOME	$ 222,929,949	$ 168,586,840	$ 164,668,228
EARNINGS PER SHARE:
Basic (in dollars per share)	$ 1.55	$ 1.18	$ 1.16
Diluted (in dollars per share)	$ 1.55	$ 1.17	$ 1.14
Cash Dividends Declared per Share (in dollars per share)	$ 0.56	$ 0.52	$ 0.48