| Note 9 - Share-based Compensation | 3 Months Ended | 
|---|---|
| Sep. 30, 2020 | |
| Notes to Financial Statements | |
| Share-based Payment Arrangement [Text Block] | Note 9. Share-based Compensation: 
 During the quarter ended September 30, 2020 and 2019, the Company granted 0.7 million and 0.7 million stock options at weighted average grant prices of $267.79 and $190.39 and weighted average fair values of $56.71 and $36.72, respectively. During the quarter ended September 30, 2020 and 2019, the Company granted 22,367 and 30,858 restricted stock units at a weighted average fair value of $267.87 and $192.08, respectively. During the quarter ended September 30, 2020 and 2019, the Company granted 8,675 and 11,438 shares of restricted common stock shares at a weighted average fair value of $267.98 and $190.65. 
 Stock options for 116,816 and 93,596 shares of common stock with total intrinsic values of $16.9 million and $11.6 million were exercised during the quarter ended September 30, 2020 and 2019, respectively. 
 Stock-based compensation expense of $12.9 million and $8.4 million was included in selling, general and administrative expenses for the quarter ended September 30, 2020 and 2019, respectively. Additionally, stock-based compensation costs of $0.5 million and $0.4 million was included in cost of goods sold for quarter ended September 30, 2020 and 2019, respectively. As of September 30, 2020, there was $53.2 million of unrecognized compensation cost related to non-vested stock options, non-vested restricted stock units and non-vested restricted stock. The weighted average period over which the compensation cost is expected to be recognized is 2.1 years. 
 
 |