XML 51 R41.htm IDEA: XBRL DOCUMENT
v3.21.2

Summary of Investment Securities Gross Unrealized Gains (Losses) (Details) - USD ($) | Jun. 30, 2021 | Dec. 31, 2020
--- | --- | ---
Investments, Debt and Equity Securities [Abstract] |  |
Investments with unrealized gains, Fair Value | $ 5,998,980 |
Investments with unrealized gains, Unrealized Holding Gains (Losses) | 1,073 |
Investments with unrealized losses, Fair Value | 25,924,305 |
Investments with unrealized Losses, Unrealized Holding Gains (Losses) | (4,843) |
Investment securities, available for sale | 31,923,285 |
Investments with unrealized Gains (Losses), Unrealized Holding Gains (Losses) | $ (3,770) |

X
- Definition Available for sale securities unrealized gains fair value. + References No definition available. + Details
Name: | CLSN_AvailableForSaleSecuritiesUnrealizedGainsFairValue
Namespace Prefix: | CLSN_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Available for sale securities unrealized gains less than twelve months. + References No definition available. + Details
Name: | CLSN_AvailableForSaleSecuritiesUnrealizedHoldingGainsLessThanTwelveMonths
Namespace Prefix: | CLSN_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Available for sale securities unrealized gains (losses) less than twelve months. + References No definition available. + Details
Name: | CLSN_AvailableForSaleSecuritiesUnrealizedHoldingGainsLossesLessThanTwelveMonths
Namespace Prefix: | CLSN_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Available for sale securities unrealized losses less than twelve months. + References No definition available. + Details
Name: | CLSN_AvailableForSaleSecuritiesUnrealizedHoldingLossesLessThanTwelveMonths
Namespace Prefix: | CLSN_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Available for sale securities unrealized losses fair value. + References No definition available. + Details
Name: | CLSN_AvailableForSaleSecuritiesUnrealizedLossFairValue
Namespace Prefix: | CLSN_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), classified as current. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=124260329&loc=d3e26626-111562 + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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