CONDENSED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
REVENUE:
Product Development and Licensing Agreements	$ 342	$ 35
Contracts and Grants	144cldx_RevenueFromContractsAndGrants	381cldx_RevenueFromContractsAndGrants
Total Revenue	486us-gaap_Revenues	416us-gaap_Revenues
OPERATING EXPENSE:
Research and Development	25,125us-gaap_ResearchAndDevelopmentExpense	27,070us-gaap_ResearchAndDevelopmentExpense
General and Administrative	6,089us-gaap_GeneralAndAdministrativeExpense	4,582us-gaap_GeneralAndAdministrativeExpense
Amortization of Acquired Intangible Assets	253us-gaap_AmortizationOfIntangibleAssets	253us-gaap_AmortizationOfIntangibleAssets
Total Operating Expense	31,467us-gaap_CostsAndExpenses	31,905us-gaap_CostsAndExpenses
Operating Loss	(30,981)us-gaap_OperatingIncomeLoss	(31,489)us-gaap_OperatingIncomeLoss
Investment and Other Income, Net	807us-gaap_InterestAndOtherIncome	1,586us-gaap_InterestAndOtherIncome
Net Loss	(30,174)	(29,903)
Basic and Diluted Net Loss Per Common Share (in dollars per share)	$ (0.33)us-gaap_EarningsPerShareBasicAndDiluted	$ (0.33)us-gaap_EarningsPerShareBasicAndDiluted
Shares Used in Calculating Basic and Diluted Net Loss per Share (in shares)	92,437	89,270
COMPREHENSIVE LOSS:
Net Loss	(30,174)	(29,903)
Other Comprehensive Income:
Foreign Currency Translation Adjustments	15	1
Unrealized Gain on Marketable Securities	11	1
Comprehensive Loss	$ (30,148)us-gaap_ComprehensiveIncomeNetOfTax	$ (29,901)us-gaap_ComprehensiveIncomeNetOfTax

This element represents revenue earned during the period arising from products sold or services provided under the terms of a contract. Also include revenue earned during the period from non-repayable sum of money awarded to an entity to carry out a specific purpose as provided in grant agreements.

No definition available.