Condensed Consolidated Balance Sheets (USD $)	Mar. 31, 2013		Dec. 31, 2012
ASSETS
Cash and cash equivalents	$ 442,552,961		$ 389,678,664
Short-term investments	75,951,991		60,802,856
Accounts receivable, net	121,927,126		109,579,693
Inventories	130,069,690		159,930,266
Prepaid expenses and other	24,755,707		24,671,561
Total current assets	795,257,475		744,663,040
PLANT AND EQUIPMENT—NET	348,055,549		349,938,172
OTHER ASSETS
Long-term investments	158,211,405		141,834,034
Patents and other assets, net	28,607,847		29,256,089
Total other assets	186,819,252		171,090,123
Total assets	1,330,132,276		1,265,691,335
LIABILITIES AND SHAREHOLDERS’ INVESTMENT
Accounts payable	33,001,922		43,200,002
Accrued liabilities	76,653,390		44,757,440
Total current liabilities	109,655,312		87,957,442
DEFERRED INCOME TAXES	58,029,136		56,773,337
SHAREHOLDERS’ INVESTMENT
Common stock	8,615,042		8,584,581
Additional paid-in capital	429,519,108		418,766,010
Retained earnings	701,368,056		676,039,254
Accumulated other comprehensive income	22,945,622	[1]	17,570,711
Total shareholders’ investment	1,162,447,828		1,120,960,556
Total liabilities and shareholders’ investment	$ 1,330,132,276		$ 1,265,691,335

[1] All amounts are shown net of tax. Amounts in parentheses indicate debits.