CONSOLIDATED STATEMENTS OF EARNINGS AND COMPREHENSIVE INCOME (USD $)
In Thousands, except Per Share data, unless otherwise specified
 12 Months Ended
Jun. 30, 2012
Jun. 30, 2011
Jun. 30, 2010
Net sales $ 314,560 $ 289,962 $ 269,047
Cost of sales 78,756 65,025 54,898
Gross margin 235,804 224,937 214,149
Operating expenses:      
Selling, general and administrative 41,683 35,897 32,700
Research and development 27,912 25,985 25,121
Total operating expenses 69,595 61,882 57,821
Operating income 166,209 163,055 156,328
Other income (expense):      
Interest income 2,639 3,752 4,375
Impairment losses on investments (3,254) 0 0
Other non-operating expense, net (3,399) (1,826) (4,257)
Total other (expense) income (4,014) 1,926 118
Earnings before income taxes 162,195 164,981 156,446
Income taxes 49,864 52,679 46,670
Net earnings 112,331 112,302 109,776
Other comprehensive income (loss):      
Foreign currency translation adjustments (3,804) 5,028 (13,932)
Unrealized gains (losses) on available-for-sale investments, net of tax of $23,422, ($44) and $97, respectively 41,870 (85) 175
Other comprehensive income (loss) 38,066 4,943 (13,757)
Comprehensive income $ 150,397 $ 117,245 $ 96,019
Earnings per share:      
Basic $ 3.04 $ 3.03 $ 2.95
Diluted $ 3.04 $ 3.02 $ 2.94
Cash dividends per common share: $ 1.11 $ 1.07 $ 1.03
Weighted average common shares outstanding:      
Basic 36,939 37,098 37,255
Diluted 37,006 37,172 37,347