Income Taxes Significant Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Capitalized research expense	$ 5,250	$ 6,300
NOL carryforwards	127,835	110,788
Research and development and other tax credits	13,242	11,737
Deferred revenue	1,628	1,506
Stock-based compensation	3,256	3,255
Acquired intangibles	757	889
Derivative liability	0	1,852
Interest expense	564	1,122
Investment in affiliated entity	542	645
Lease liability	4,283	4,722
Other	6,127	2,413
Deferred tax assets, gross	163,484	145,229
Valuation allowance	(159,705)	(137,159)
Total deferred tax assets	3,779	8,070
Deferred tax liabilities:
Acquired intangibles	(179)	(160)
Right of use asset	(2,676)	(2,894)
Note discount	(469)	(2,862)
Convertible note	0	(1,381)
Fixed assets	(487)	(805)
Net deferred tax liabilities	$ (32)	$ (32)

Deferred Tax Asset, Interest Expense

No definition available.

Name:	ino_DeferredTaxAssetInterestExpense
Namespace Prefix:	ino_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Deferred Tax Assets, Intangible Assets

+ References

No definition available.

+ Details

Name:	ino_DeferredTaxAssetsIntangibleAssets
Namespace Prefix:	ino_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Deferred Tax Assets, Operating Lease Liability

+ References

No definition available.

+ Details

Name:	ino_DeferredTaxAssetsOperatingLeaseLiability
Namespace Prefix:	ino_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Deferred Tax Liabilities, Financing Arrangement, Discount

+ References

No definition available.

+ Details

Name:	ino_DeferredTaxLiabilitiesFinancingArrangementDiscount
Namespace Prefix:	ino_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Deferred Tax Liabilities, Operating Lease, Right-Of-Use Asset

+ References

No definition available.

+ Details

Name:	ino_DeferredTaxLiabilitiesOperatingLeaseRightOfUseAsset
Namespace Prefix:	ino_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_ComponentsOfDeferredTaxLiabilitiesAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from deferred income.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32632-109319

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32621-109319

+ Details

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

- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from derivative instruments.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32621-109319

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32632-109319

+ Details

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

- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319

+ Details

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

- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from in-process research and development costs expensed in connection with a business combination.

+ References

+ Details

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

- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from investments (excludes investments in subsidiaries and equity method investments).

+ References

No definition available.

+ Details

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

- Definition

Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319

+ Details

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

- References

No definition available.

+ Details

Name:	us-gaap_DeferredTaxAssetsNetAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards.

+ References

+ Details

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

- Definition

Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences, classified as other.

+ References

+ Details

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

- Definition

Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible tax carryforwards, classified as other.

+ References

+ Details

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

- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from share-based compensation.

+ References

+ Details

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

- Definition

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319

+ Details

Name:	us-gaap_DeferredTaxAssetsValuationAllowance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount, after deferred tax asset, of deferred tax liability attributable to taxable differences without jurisdictional netting.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=120406818&loc=d3e31931-109318

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319

+ Details

Name:	us-gaap_DeferredTaxLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of deferred tax liability attributable to taxable temporary differences from financing arrangements.

+ References

+ Details

Name:	us-gaap_DeferredTaxLiabilitiesFinancingArrangements
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of deferred tax liability attributable to taxable temporary differences from intangible assets other than goodwill.

+ References

+ Details

Name:	us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of deferred tax liability attributable to taxable temporary differences from property, plant, and equipment.

+ References

+ Details

Name:	us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant