Note 10 - Share-based Compensation and Other Benefit Plans - Restricted Stock and Restricted Stock Units Activity (Details) - $ / shares shares in Thousands	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
Restricted Stock [Member]
Balance, shares (in shares)	28	30	35
Balance, weighted average exercise price (in dollars per share)	$ 177.20	$ 147.94	$ 117.39
Granted, shares (in shares)	12	15	15
Granted, weighted average exercise price (in dollars per share)	$ 264.73	$ 193.48	$ 177.93
Vested, shares (in shares)	(17)	(18)	(20)
Vested, weighted average exercise price (in dollars per share)	$ 171.64	$ 142.12	$ 116.76
Forfeited, shares (in shares)	0	0	0
Forfeited, weighted average exercise price (in dollars per share)	$ 0	$ 0	$ 0
Balance, weighted average contractual life (Year)	6 years 25 days
Balance, shares (in shares)	23	28	30
Balance, weighted average exercise price (in dollars per share)	$ 226.07	$ 177.20	$ 147.94
Restricted Stock Units (RSUs) [Member]
Balance, shares (in shares)	116	139	148
Balance, weighted average exercise price (in dollars per share)	$ 159.25	$ 134.17	$ 117.95
Granted, shares (in shares)	31	31	56
Granted, weighted average exercise price (in dollars per share)	$ 300.78	$ 192.08	$ 170.96
Vested, shares (in shares)	(51)	(51)	(28)
Vested, weighted average exercise price (in dollars per share)	$ 130.18	$ 111.07	$ 110.86
Forfeited, shares (in shares)	0	(3)	(36)
Forfeited, weighted average exercise price (in dollars per share)	$ 0	$ 155.60	$ 143.72
Balance, weighted average contractual life (Year)	5 years 4 months 9 days
Balance, shares (in shares)	96	116	139
Balance, weighted average exercise price (in dollars per share)	$ 220.53	$ 159.25	$ 134.17