Summary of Significant Accounting Policies - Investments in Marketable Securities (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Jun. 30, 2024
Marketable securities
Investment income, nonoperating	$ 8,200	$ 5,500
Marketable securities, short-term portion	204,500		$ 191,700
Marketable securities, long-term portion	$ 17,100		$ 21,900
Marketable Securities, Maturity Date, Start	1 year		1 year
Marketable Securities, Maturity Date, End	2 years		2 years
Amortized Cost	$ 221,593		$ 213,589
Allowance for Credit Losses	0		0
Net Carrying Amount	221,593		213,589
Gross Unrealized Gains (Losses)			(164)
Gross Unrealized Gains	347
Fair Value	221,940		213,425
Corporate Bonds
Marketable securities
Amortized Cost	48,246		45,752
Net Carrying Amount	48,246		45,752
Gross Unrealized Gains (Losses)			(95)
Gross Unrealized Gains	224
Fair Value	48,470		45,657
U.S. Treasury Notes
Marketable securities
Amortized Cost	55,337		46,760
Net Carrying Amount	55,337		46,760
Gross Unrealized Gains (Losses)			(71)
Gross Unrealized Gains	123
Fair Value	55,460		46,689
Commercial Paper
Marketable securities
Amortized Cost	118,010		121,077
Net Carrying Amount	118,010		121,077
Gross Unrealized Gains			2
Fair Value	$ 118,010		$ 121,079