Note 12 - Earn Out Milestone Liability (Details) - Summary of the Changes in the Earn-Out Milestone Liability (USD $)	12 Months Ended
Dec. 31, 2014
Summary of the Changes in the Earn-Out Milestone Liability [Abstract]
Balance	$ 0clsn_EarnOutMilestoneLiability
Fair value of Earn-Out Payments at date of EGEN Purchase Agreement (Note 5)	13,878,204
Gain from the adjustment for the change in fair value included in net income	(213,494)
Balance	$ 13,663,710clsn_EarnOutMilestoneLiability

Amount of liabilities incurred by the acquirer as part of consideration transferred in a business combination.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 25

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6405-128476

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 30

-Paragraph 7

-URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6578-128477

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 30

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6613-128477

Name:	us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration