Consolidated Balance Sheets (USD $)	Dec. 31, 2011	Dec. 31, 2010
ASSETS
Cash and cash equivalents	$ 357,986,774	$ 348,349,773
Short-term investments	60,808,237	86,447,596
Accounts receivable	110,389,715	95,647,612
Inventories	188,753,312	100,728,730
Prepaid expenses and other	34,354,946	24,095,563
Total current assets	752,292,984	655,269,274
PLANT AND EQUIPMENT:
Land, buildings and improvements	130,290,789	120,578,714
Machinery and equipment	415,394,183	352,618,391
Construction-in-process	58,244,561	13,351,954
Plant and equipment, gross	603,929,533	486,549,059
Less-Accumulated depreciation and amortization	(321,387,945)	(281,441,303)
Plant and equipment, net	282,541,588	205,107,756
OTHER ASSETS
Long-term investments	128,168,165	129,091,167
Patents and other assets, net	13,024,265	13,222,442
Total other assets	141,192,430	142,313,609
Total assets	1,176,027,002	1,002,690,639
LIABILITIES AND SHAREHOLDERS' INVESTMENT
Accounts payable	65,470,573	40,295,464
Accrued liabilities:
Salaries, wages and vacation	6,558,638	5,724,818
Royalties	6,745,877	4,988,132
Dividends declared	17,288,348	15,652,134
Other	4,631,064	5,428,081
Total current liabilities	100,694,500	72,088,629
DEFERRED INCOME TAXES	48,213,981	37,071,184
SHAREHOLDERS' INVESTMENT:
Preferred stock, no par value, 5,000,000 shares authorized; none issued or outstanding
Common stock, par value $.06 per share; 200,000,000 shares authorized; 144,069,563 shares issued and outstanding in 2011 and 142,292,127 shares issued and outstanding in 2010	8,644,174	8,537,528
Additional paid-in capital	395,229,891	347,834,218
Retained earnings	610,702,253	514,842,177
Accumulated other comprehensive income:
Unrealized gain on investments	10,412,246	21,750,000
Cumulative translation adjustment	2,129,957	566,903
Total shareholders' investment	1,027,118,521	893,530,826
Total liabilities and shareholders' investment	$ 1,176,027,002	$ 1,002,690,639