Marketable Securities and Fair Value Measurements
 12 Months Ended
Dec. 31, 2021
Fair Value Disclosures [Abstract]  
Marketable Securities and Fair Value Measurements Marketable Securities and Fair Value Measurements
As of December 31, 2021, available for sale marketable securities by security type consisted of (in thousands):
Amortized
Cost		Gross
Unrealized
Gains		Gross
Unrealized
Losses		Estimated
Fair
Value
Commercial paper (due within one year)$36,246 $— $(3)$36,243 
Corporate notes and bonds (due within one year)16,917 — (7)16,910 
Total$53,163 $— $(10)$53,153 
As of December 31, 2020, available for sale marketable securities by security type consisted of (in thousands):
Amortized
Cost		Gross
Unrealized
Gains		Gross
Unrealized
Losses		Estimated
Fair
Value
U.S. treasury notes (due within one year)$92,982 $— $(7)$92,975 
Total$92,982 $— $(7)$92,975 
The following tables present the Company’s fair value hierarchy for its assets and liabilities, which were measured at fair value on a recurring basis (in thousands):
Fair Value Measurements at
December 31, 2021 Using:
Level 1Level 2Level 3Total
Assets:
Cash equivalents:
Money market funds
$82,252 $— $— $82,252 
Commercial paper— 18,496 — 18,496 
Marketable securities:
Commercial paper— 36,243 — 36,243 
Corporate notes and bonds— 16,910 — 16,910 
Total$82,252 $71,649 $— $153,901 
Fair Value Measurements at
December 31, 2020 Using:
Level 1Level 2Level 3Total
Assets:
Cash equivalents:
Money market funds$48,770 $— $— $48,770 
U.S. treasury notes— 42,997 — 42,997 
Marketable securities:
U.S. treasury notes— 92,975 — 92,975 
Total$48,770 $135,972 $— $184,742 
During the years ended December 31, 2021 and 2020, there were no transfers between Level 1, Level 2 and Level 3.