Fair Value Measurements (Tables)

3 Months Ended

9 Months Ended

Mar. 31, 2020

Mar. 31, 2020

Fair Value Disclosures [Abstract]

Summary of Company's Money Market Funds and Marketable Securities

The following tables summarize the Company’s money market funds and marketable securities as of March 31, 2020 and December 31, 2019.

	March 31, 2020
	Total		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
	(in thousands)
Cash equivalents:
Cash equivalents	$	199,444	$	169,249	$	30,195	$	—
Total cash equivalents		199,444		169,249		30,195		—
Marketable securities:
U.S. government securities		145,913		—		145,913		—
U.S. corporate bonds		362,161		—		362,161		—
International corporate bonds		116,396		—		116,396		—
U.S. commercial paper		27,904		—		27,904		—
International commercial paper		20,939		—		20,939		—
Total marketable securities		673,313		—		673,313		—
	$	872,757	$	169,249	$	703,508	$	—

	December 31, 2019
	Total		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
	(in thousands)
Cash equivalents:
Cash equivalents	$	126,705	$	65,414	$	61,291	$	—
Total cash equivalents		126,705		65,414		61,291		—
Marketable securities:
U.S. government securities		205,328		—		205,328		—
U.S. corporate bonds		429,845		—		429,845		—
International corporate bonds		142,998		—		142,998		—
U.S. commercial paper		52,261		—		52,261		—
International commercial paper		51,256		—		51,256		—
Total marketable securities		881,688		—		881,688		—
	$	1,008,393	$	65,414	$	942,979	$	—

Summary of Gross Unrealized Gains and Losses of Marketable Securities

The following tables summarize the gross unrealized gains and losses of the Company’s marketable securities as of March 31, 2020 and December 31, 2019:

	March 31, 2020
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Credit Losses		Fair Value
	(in thousands)
Assets:
U.S. government securities	$	145,202	$	711	$	—		$	—	$	145,913
U.S. corporate bonds		363,156		415		(1,410	)		—		362,161
International corporate bonds		116,878		180		(662	)		—		116,396
U.S. commercial paper		27,930		—		(26	)		—		27,904
International commercial paper		20,939		—		—			—		20,939
	$	674,105	$	1,306	$	(2,098	)	$	—	$	673,313