Condensed Consolidated Statements of Earnings and Comprehensive Income (Unaudited) - USD ($)
shares in Thousands, $ in Thousands
 3 Months Ended 9 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Mar. 31, 2018
Mar. 31, 2017
Net sales $ 163,973 $ 144,037 $ 462,739 $ 406,425
Cost of sales 53,712 47,355 152,777 134,256
Gross margin 110,261 96,682 309,962 272,169
Operating expenses:        
Selling, general and administrative 53,285 49,409 175,349 151,814
Research and development 13,892 13,771 41,350 39,817
Total operating expenses 67,177 63,180 216,699 191,631
Operating income 43,084 33,502 93,263 80,538
Other income (expense), net (18,102) (2,361) (23,581) (6,425)
Earnings before income taxes 24,982 31,141 69,682 74,113
Income tax expense (benefit) 5,244 8,974 (14,767) 25,637
Net earnings 19,738 22,167 84,449 48,476
Other comprehensive income:        
Foreign currency translation adjustments 2,297 2,400 10,787 (10,899)
Unrealized gain (loss) on available-for-sale investments, net of tax of $(10,120), $293, $(4,745), and $(1,767), respectively 38,659 (475) 22,286 16,010
Other comprehensive income 40,956 1,925 33,073 5,111
Comprehensive income $ 60,694 $ 24,092 $ 117,522 $ 53,587
Earnings per share:        
Basic (in dollars per share) $ 0.53 $ 0.59 $ 2.25 $ 1.30
Diluted (in dollars per share) 0.52 0.59 2.22 1.29
Cash dividends per common share: (in dollars per share) $ 0.32 $ 0.32 $ 0.96 $ 0.96
Weighted average common shares outstanding:        
Basic (in shares) 37,503 37,320 37,450 37,303
Diluted (in shares) 38,142 37,494 37,933 37,486