Consolidated Statements Of Income (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Statement [Abstract]
NET SALES	$ 1,099,559,521	$ 1,023,762,049	$ 816,263,414
COST OF GOODS SOLD	726,740,962	662,181,714	520,573,101
Gross profit	372,818,559	361,580,335	295,690,313
OPERATING EXPENSES:
Engineering, research and development	85,003,602	81,634,158	64,100,411
Selling, general and administrative	48,359,725	48,578,252	40,617,833
Litigation Settlement	5,000,000	0	0
Total operating expenses	138,363,327	130,212,410	104,718,244
Income from operations	234,455,232	231,367,925	190,972,069
OTHER INCOME (EXPENSE):
Investment income	5,307,180	4,165,809	2,901,956
Other, net	9,863,188	8,898,077	9,565,989
Total other income (expense)	15,170,368	13,063,886	12,467,945
Income before provision for income taxes	249,625,600	244,431,811	203,440,014
PROVISION FOR INCOME TAXES	81,038,760	79,763,583	65,706,045
NET INCOME	$ 168,586,840	$ 164,668,228	$ 137,733,969
EARNINGS PER SHARE:
Basic (usd per share)	$ 1.18	$ 1.16	$ 0.99
Diluted (usd per share)	$ 1.17	$ 1.14	$ 0.98
Cash Dividends Declared per Share	$ 0.52	$ 0.48	$ 0.44