Represents the area of office space leased during the period.

No definition available.

Name:	tgtx_AreaOfOfficeSpaceLeased
Namespace Prefix:	tgtx_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	duration

- Definition

Average Annual Rental Payments.

+ References

No definition available.

+ Details

Name:	tgtx_AverageAnnualRentalPayments
Namespace Prefix:	tgtx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the initial commitment period under the office space lease arrangement.

+ References

No definition available.

+ Details

Name:	tgtx_OfficeSpaceLeaseInitialCommitmentPeriod
Namespace Prefix:	tgtx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Operating Lease Initial Commitment Period

+ References

No definition available.

+ Details

Name:	tgtx_OperatingLeaseInitialCommitmentPeriod
Namespace Prefix:	tgtx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

It represents percentage of occupancy.

+ References

No definition available.

+ Details

Name:	tgtx_PercentageOfOccupancy
Namespace Prefix:	tgtx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents amount received for sub license.

+ References

No definition available.

+ Details

Name:	tgtx_UpfrontFeeReceivedFromSubLicense
Namespace Prefix:	tgtx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The aggregate fair value of additional assets that would be required to be posted as collateral for derivative instruments with credit-risk-related contingent features if the credit-risk-related contingent features were triggered at the end of the reporting period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4H
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624258-113959

+ Details

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

- Definition

Costs of sales and operating expenses for the period incurred from transactions with related parties.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2)
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

+ Details

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

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

+ Details

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

- Definition

Present value of lessee's discounted obligation for lease payments from operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977

+ Details

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

- Definition

Amount of lessee's right to use underlying asset under operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977

+ Details

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

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

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=tgtx_OfficeAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=tgtx_SharedServicesAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=tgtx_CollaborationAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

RELATED PARTY TRANSACTIONS (Details) $ in Thousands	1 Months Ended			3 Months Ended			9 Months Ended
RELATED PARTY TRANSACTIONS (Details) $ in Thousands	Oct. 31, 2019 USD ($)	Jun. 30, 2019 USD ($)	Oct. 31, 2014 USD ($) ft²	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Dec. 31, 2014	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)	Jan. 01, 2019 USD ($)	Apr. 30, 2018 USD ($)
Related Party Transaction [Line Items]
Operating Lease Liability				$ 11,420			$ 11,420
Right-of-use-assets				8,983			$ 8,983		$ 9,402
Office Agreement [Member]
Related Party Transaction [Line Items]
Percentage Of Occupancy			45.00%			45.00%	65.00%
Area of leases office space \| ft²			24,000
Operating Lease Initial Commitment Period			15 years
Average Annual Rental Payments	$ 300		$ 1,100				$ 1,400
Operating Lease Liability				11,400			11,400			$ 9,300
Right-of-use-assets				9,000			9,000			$ 7,700
Initial commitment period for office lease space			3 years
Long-term Line of Credit			$ 600
Additional collateral pledged											$ 600
Upfront fee				30,000,000	$ 2,700		1,000	$ 4,000
Shared Services Agreement [Member]
Related Party Transaction [Line Items]
Costs and Expenses, Related Party				$ 200	$ 200		$ 600	$ 600
Collaboration Agreement [Member]
Related Party Transaction [Line Items]
Upfront fee		$ 1,000