Condensed Consolidated Statements Of Income (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
NET SALES	$ 269,498,969	$ 290,706,762
COST OF GOODS SOLD	176,035,466	189,880,269
Gross profit	93,463,503	100,826,493
OPERATING EXPENSES:
Engineering, research and development	18,683,576	23,215,134
Selling, general & administrative	10,926,288	12,110,396
Total operating expenses	29,609,864	35,325,530
Income from operations	63,853,639	65,500,963
OTHER INCOME (EXPENSE)
Investment income	495,413	596,023
Other, net	1,404,860	2,690,337
Total other income	1,900,273	3,286,360
Income before provision for income taxes	65,753,912	68,787,323
PROVISION FOR INCOME TAXES	20,323,345	22,442,739
NET INCOME	$ 45,430,567	$ 46,344,584
EARNINGS PER SHARE:
Basic (usd per share)	$ 0.32	$ 0.32
Diluted (usd per share)	$ 0.32	$ 0.32
Cash Dividends Declared per Share (usd per share)	$ 0.14	$ 0.13