Fair Value Measurement (Tables)

3 Months Ended

Mar. 31, 2021

Fair Value Disclosures [Abstract]

Schedule of assets and liabilities measured at fair value

Assets and liabilities measured at fair value on a recurring basis consist of the following as of March 31, 2021 (in thousands):

			Fair Value Measurements at Reporting Date Using
	March 31, 2021		Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Money market funds	$	4,941	$	4,941	$	—	$	—
Marketable securities:
Tax-exempt municipal securities	19,241		—		19,241		—
Corporate debt securities	16,494		—		16,494		—
Total assets at fair value on a recurring basis	$	40,676	$	4,941	$	35,735	$	—
Liabilities:
Deferred payments	$	1,346	$	—	$	—	$	1,346

Assets and liabilities measured at fair value on a recurring basis consist of the following as of December 31, 2020 (in thousands):

			Fair Value Measurements at Reporting Date Using
	December 31, 2020		Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Money market funds	$	2,841	$	2,841	$	—	$	—
Marketable securities:
Tax-exempt municipal securities	20,289		—		20,289		—
Corporate debt securities	17,538		—		17,538		—
Total assets at fair value on a recurring basis	$	40,668	$	2,841	$	37,827	$	—
Liabilities:
Deferred payments	$	1,658	$	—	$	—	$	1,658

Schedule of changes in fair value of level 3 liability

Changes in the fair value of the Company’s Level 3 liabilities during the three months ended March 31, 2020 and 2021 are as follows (in thousands):

	As of March 31,
	2020		2021
Balance as of the beginning of period	$	3,257	$	1,658
Amounts paid	(808)		(730)
Other adjustments to fair value	282		418
Balance at end of period	$	2,731	$	1,346