Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2019

Fair Value Measurements

Summary of financial assets and liabilities measured on recurring basis

	December 31, 2019								December 31, 2018
	Level I		Level II		Level III		Total		Level I		Level II		Level III		Total
	(in thousands)
Financial Assets:
Money market deposits	$	22,477	$	—	$	—	$	22,477	$	26,539	$	—	$	—	$	26,539
U.S. Treasury securities		293,157		—		—		293,157		75,685		—		—		75,685
U.S. agency securities		—		—		—		—		—		12,891		—		12,891
Municipal securities		—		85,908		—		85,908		—		18,885		—		18,885
Total financial assets	$	315,634	$	85,908	$	—	$	401,542	$	102,224	$	31,776	$	—	$	134,000