Amortization of debt discount.

No definition available.

Name:	mgtx_AmortizationOfDebtDiscount
Namespace Prefix:	mgtx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Floor percentage for basis points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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- Definition

Amount of debt discount to be amortized over the term of the financing agreement with Perceptive Credit Holdings.

+ References

No definition available.

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

Liquidity requirement for minimum amount of cash and bank accounts to be maintained and secured under the financing agreement with Perceptive Credit Holdings.

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Period of time between changes in the offered SOFR rate, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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- Definition

Shares available for purchase in connection with the financing agreement with Perceptive Credit Holdings.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Debt discount recorded and allocated to certain lender and legal costs in connection with the financing agreement with Perceptive Credit Holdings.

+ References

No definition available.

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

Debt discount recorded and allocated to the fair value of warrants issued under the financing agreement with Perceptive Credit Holdings.

+ References

No definition available.

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-3

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Period Type:	instant

- Definition

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

+ References

+ Details

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

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

- Definition

Increase for accrued, but unpaid interest on the debt instrument for the period.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(f))
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount, after accumulated amortization, of debt discount.

+ References

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

- Definition

Amount of unused borrowing capacity under the long-term financing arrangement that is available to the entity as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Sum of the amount of expected guaranteed benefits in excess of the projected account balances for minimum guaranteed benefit contracts, as of the balance sheet date, net of reinsurance recoverables, for all guaranteed benefit types.

+ References

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

- Definition

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

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

- 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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
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+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average interest rate of long-term debt outstanding calculated at point in time.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
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- Definition

Carrying value as of the balance sheet date of the portion of long-term, collateralized debt obligations due within one year or the operating cycle, if longer. Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Period Type:	instant

- Details

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- Details

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Debt Financing (Details) - USD ($)		3 Months Ended		6 Months Ended
Debt Financing (Details) - USD ($)	Aug. 02, 2022	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Line of Credit Facility [Line Items]
Common stock, shares issued		64,684,187		64,684,187		63,601,015
Perceptive Credit Holdings \| Secured Debt
Line of Credit Facility [Line Items]
Unamortized debt discount, warrants		$ 2,300,000		$ 2,300,000
Unamortized debt discount, legal costs		2,100,000		2,100,000
Unamortized debt discount, gross		4,400,000		4,400,000
Amortization of debt discount		300,000	$ 300,000	500,000	$ 500,000
Remaining unamortized discount on debt, total		2,300,000		2,300,000
Perceptive Credit Holdings \| Secured Debt \| Exercise Price - Scenario I
Line of Credit Facility [Line Items]
Shares available through warrants	$ 400,000
Warrant exercise price	$ 15.00
Perceptive Credit Holdings \| Secured Debt \| Exercise Price - Scenario II
Line of Credit Facility [Line Items]
Shares available through warrants	$ 300,000
Warrant exercise price	$ 20.00
Perceptive Credit Holdings \| Secured Debt \| Term Loan
Line of Credit Facility [Line Items]
Initial face amount	$ 75,000,000.0
Unused borrowing capacity	$ 25,000,000.0
Term loan outstanding amount		$ 75,000,000.0		$ 75,000,000.0
Interest rate at period-end		15.33%		15.33%
Increase in accrued interest				$ 2,900,000
Interest expense on debt		$ 2,900,000	$ 2,800,000	5,800,000	$ 5,500,000
Obligations secured by UK and Ireland subsidiaries		3,000,000.0		3,000,000.0
Cash liquidity requirement		$ 3,000,000.0		$ 3,000,000.0
Perceptive Credit Holdings \| Secured Debt \| Term Loan \| Base Rate [Member]
Line of Credit Facility [Line Items]
Stated interest rate	10.00%
Perceptive Credit Holdings \| Secured Debt \| Term Loan \| SOFR
Line of Credit Facility [Line Items]
Floor percentage	1.00%
SOFR adjustment term	1 month