Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2020

Fair Value Measurements

Summary of financial assets and liabilities measured on recurring basis

	June 30, 2020								December 31, 2019
	Level I		Level II		Level III		Total		Level I		Level II		Level III		Total
	(in thousands)
Financial Assets:
Money market deposits	$	28,795	$	—	$	—	$	28,795	$	22,477	$	—	$	—	$	22,477
U.S. Treasury securities		404,416		—		—		404,416		293,157		—		—		293,157
Municipal securities		—		89,436		—		89,436		—		85,908		—		85,908
Total financial assets	$	433,211	$	89,436	$	—	$	522,647	$	315,634	$	85,908	$	—	$	401,542