Stock-Based Compensation - Additional Disclosures (Details) - USD ($)	3 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Stock-based compensation, additional disclosures
Issuance of shares of common stock	$ 268,000	$ 1,018,000
Common stock reserved for future issuance or settlement (in shares)	6,000,000.0
Employee stock purchase plan, stock-based compensation	$ 6,268,000	$ 9,275,000
Restricted Stock Units
Stock-based compensation, additional disclosures
Weighted average grant-date fair value of RSUs granted	$ 107.20	$ 133.15
Total fair value of shares vested from RSU grants	$ 5,100,000	$ 10,500,000
Total unrecognized compensation cost	$ 27,800,000
Total unrecognized compensation cost, period of recognition	2 years 2 months 12 days
Excess tax benefits from stock-based compensation	$ 1,800,000	$ 3,400,000
Performance awards, shares granted	5,103
Performance awards, shares forfeited	2,985
Stock Options
Stock-based compensation, additional disclosures
Weighted average fair value (in dollars per share)	$ 31.11	$ 33.15
Total unrecognized compensation cost	$ 8,800,000
Total unrecognized compensation cost, period of recognition	2 years 2 months 12 days
Total intrinsic value of options exercised	$ 1,000,000.0	$ 1,300,000
Issuance of shares of common stock	$ 300,000	1,000,000.0
Performance Shares [Member]
Stock-based compensation, additional disclosures
Employee stock purchase plan, stock-based compensation		0
2018 Employee Stock Purchase Plan
Stock-based compensation, additional disclosures
Common stock reserved for future issuance or settlement (in shares)	217,739
Employee stock purchase plan, purchase price of common stock, percent	85.00%
Employee stock purchase plan, stock-based compensation	$ 200,000	$ 100,000
Employee stock purchase plan, number of shares authorized	250,000