XML 67 R48.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Summary of Significant Accounting Policies - Newly-Adopted Accounting Pronouncements (Details) - USD ($) $ in Millions |  | 12 Months Ended
--- | --- | ---
Jan. 01, 2017 | Dec. 31, 2017
Newly-Adopted Accounting Pronouncements |  |
Increase in deferred tax and valuation allowance |  | $ 17.7
Adjustments for New Accounting Principle, Early Adoption | Accounting Standards Update |  |
Newly-Adopted Accounting Pronouncements |  |
Increase in deferred tax and valuation allowance | $ 17.7 |

X
- Definition Gross deferred tax assets and valuation allowance related to tax deductions from the exercise of stock options that would have been credited to additional paid-in-capital when realized. + References No definition available. + Details
Name: | cldx_GrossDeferredTaxAssetsAndCorrespondingValuation
Namespace Prefix: | cldx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_NewAccountingPronouncementEarlyAdoptionAxis=us-gaap_AdjustmentsForNewAccountingPrincipleEarlyAdoptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AdjustmentsForNewAccountingPronouncementsAxis=cldx_AccountingStandardsUpdateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |