XML 24 R11.htm IDEA: XBRL DOCUMENT
v3.21.1

Marketable Securities | 12 Months Ended
--- | ---
Dec. 31, 2020
Marketable Securities |
Marketable Securities | (5) Marketable Securities The following is a summary of marketable debt securities, classified as available-for-sale:
|  |  |  |  | Gross |  | Gross |  |  |
|  | Amortized |  | Unrealized |  | Unrealized |  | Fair
|  | Cost |  | Gains |  | Losses |  | Value
|  | (In thousands)
December 31, 2020 |  |  |  |  |  |  |  |  |  |  |  |
Marketable securities |  |  |  |  |  |  |  |  |  |  |  |
U.S. government and municipal obligations |  |  |  |  |  |  |  |  |  |  |  |
Maturing in one year or less |  | $ | 40,328 |  | $ | 3 |  | $ | (2) |  | $ | 40,329
Maturing after one year through three years |  |  | — |  |  | — |  |  | — |  |  | —
Total U.S. government and municipal obligations |  | $ | 40,328 |  | $ | 3 |  | $ | (2) |  | $ | 40,329
Corporate debt securities |  |  |  |  |  |  |  |  |  |  |  |
Maturing in one year or less |  | $ | 110,265 |  | $ | 2 |  | $ | (10) |  | $ | 110,257
Maturing after one year through three years |  |  | — |  |  | — |  |  | — |  |  | —
Total corporate debt securities |  | $ | 110,265 |  | $ | 2 |  | $ | (10) |  | $ | 110,257
Total marketable securities |  | $ | 150,593 |  | $ | 5 |  | $ | (12) |  | $ | 150,586
December 31, 2019 |  |  |  |  |  |  |  |  |  |  |  |
Marketable securities |  |  |  |  |  |  |  |  |  |  |  |
U.S. government and municipal obligations |  |  |  |  |  |  |  |  |  |  |  |
Maturing in one year or less |  | $ | 18,509 |  | $ | 13 |  | $ | — |  | $ | 18,522
Maturing after one year through three years |  |  | — |  |  | — |  |  | — |  |  | —
Total U.S. government and municipal obligations |  | $ | 18,509 |  | $ | 13 |  | $ | — |  | $ | 18,522
Corporate debt securities |  |  |  |  |  |  |  |  |  |  |  |
Maturing in one year or less |  | $ | 34,619 |  | $ | 13 |  | $ | (3) |  | $ | 34,629
Maturing after one year through three years |  |  | — |  |  | — |  |  | — |  |  | —
Total corporate debt securities |  | $ | 34,619 |  | $ | 13 |  | $ | (3) |  | $ | 34,629
Total marketable securities |  | $ | 53,128 |  | $ | 26 |  | $ | (3) |  | $ | 53,151
The Company holds investment grade marketable securities, and none were considered to be other‑than‑temporarily impaired as of December 31, 2020. Marketable securities include $0.2 million in accrued interest at December 31, 2020 and December 31, 2019.

X
- References No definition available. + Details
Name: | us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The entire disclosure for investments in certain debt and equity securities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 320 -URI http://asc.fasb.org/subtopic&trid=2209399 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 320 -URI http://asc.fasb.org/subtopic&trid=2324412 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -URI http://asc.fasb.org/topic&trid=2196928 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 940 -SubTopic 320 -URI http://asc.fasb.org/subtopic&trid=2176304 + Details
Name: | us-gaap_InvestmentsInDebtAndMarketableEquitySecuritiesAndCertainTradingAssetsDisclosureTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration