Condensed Consolidated Statements of Income (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
NET SALES	$ 286,973,898	$ 280,255,548	$ 556,472,867	$ 570,962,310
COST OF GOODS SOLD	184,361,279	187,498,242	360,396,745	377,378,511
Gross profit	102,612,619	92,757,306	196,076,122	193,583,799
OPERATING EXPENSES:
Engineering, research and development	18,864,182	22,792,503	37,547,758	46,007,637
Selling, general & administrative	12,152,166	12,452,571	23,078,454	24,562,967
Total operating expenses	31,016,348	35,245,074	60,626,212	70,570,604
Income from operations	71,596,271	57,512,232	135,449,910	123,013,195
OTHER INCOME
Investment income	625,717	633,700	1,121,130	1,229,723
Other, net	4,906,951	2,533,783	6,311,811	5,224,120
Total other income	5,532,668	3,167,483	7,432,941	6,453,843
Income before provision for income taxes	77,128,939	60,679,715	142,882,851	129,467,038
PROVISION FOR INCOME TAXES	25,031,542	19,913,176	45,354,887	42,355,915
NET INCOME	$ 52,097,397	$ 40,766,539	$ 97,527,964	$ 87,111,123
EARNINGS PER SHARE:
Basic (in dollars per share)	$ 0.36	$ 0.28	$ 0.68	$ 0.61
Diluted (in dollars per share)	$ 0.36	$ 0.28	$ 0.68	$ 0.60
Cash Dividends Declared per Share (in dollars per share)	$ 0.14	$ 0.13	$ 0.28	$ 0.26