The period for amortization of principal and interest.

No definition available.

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- Definition

The percent associated with the fees incurred on borrowings from lines of credit.

+ References

No definition available.

+ Details

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Namespace Prefix:	clsn_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of amortization expense attributable to debt issuance costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
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-Topic 225
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-Section S99
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-Subparagraph (SX 210.5-03(8))
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-Publisher FASB
-Name Accounting Standards Codification
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-Paragraph 1
-Subparagraph (SX 210.9-04(8))
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Exercise price per share or per unit of warrants or rights outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i)(4))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of securities into which each warrant or right may be converted. For example, but not limited to, each warrant may be converted into two shares.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after accumulated amortization, of debt discount.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28541-108399

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of the cost of borrowed funds accounted for as interest expense for debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.8)
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+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
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-Paragraph 14
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of cash outflow for payment of an obligation from a lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Subparagraph (b)
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-Subparagraph (SX 210.4-08.(f))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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

- Details

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- Details

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- Details

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Balance Type:
Period Type:

- Details

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- Details

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Note 9 - Note Payable (Details Textual) - USD ($)			1 Months Ended	3 Months Ended		6 Months Ended	9 Months Ended		17 Months Ended	26 Months Ended	47 Months Ended
Note 9 - Note Payable (Details Textual) - USD ($)	Jun. 20, 2014	Jun. 10, 2014	Nov. 30, 2013	Sep. 30, 2017	Sep. 30, 2016	Jun. 10, 2014	Sep. 30, 2017	Sep. 30, 2016	May 31, 2017	Dec. 17, 2015	Sep. 30, 2017	Jun. 26, 2017	Jun. 09, 2017	Dec. 31, 2016	Jun. 30, 2015	Nov. 25, 2013
Class of Warrant or Right, Exercise Price of Warrants or Rights				$ 5.33			$ 5.33				$ 5.33	$ 1.65	$ 2.70	$ 9.39
Hercules Warrant [Member]
Debt Instrument, Unamortized Discount		$ 476,261				$ 476,261
EGEN Inc [Member]
Payments to Acquire Businesses, Gross	$ 3,000,000
Hercules Credit Agreement [Member]
Repayments of Lines of Credit			$ 4,000,000
Interest Expense, Debt				$ 0	$ 107,805		$ 56,386	$ 409,770
Amortization of Debt Issuance Costs				0	$ 53,220		35,370	$ 198,806
Hercules Credit Agreement [Member] \| Hercules Warrant [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights																$ 50.26
Line of Credit Facility Original Loan Fee Percent															3.50%
Debt Issuance Costs, Gross															$ 350,000
Hercules Credit Agreement [Member] \| EGEN Inc [Member]
Payments to Acquire Businesses, Gross		3,000,000
Hercules [Member]
Repayments of Lines of Credit		$ 5,000,000
Hercules [Member] \| Hercules Credit Agreement [Member]
Line of Credit Facility, Maximum Borrowing Capacity			20,000,000
Proceeds from Lines of Credit			5,000,000			$ 10,000,000
Debt Instrument, Basis Spread on Variable Rate									11.50%	11.25%
Amortization Period for Principal and Interest											2 years 180 days
Debt Issuance Costs, Net				$ 122,378			$ 122,378				$ 122,378
Debt Instrument, Unamortized Discount			$ 230,000
Hercules [Member] \| Hercules Credit Agreement [Member] \| First Fifty Percent [Member]
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right																6,963
Hercules [Member] \| Hercules Credit Agreement [Member] \| Second Fifty Percent [Member]
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right																6,963