XML 68 R57.htm IDEA: XBRL DOCUMENT
v3.25.3

Debt - Long-term Debt - Narrative (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024
Debt Disclosure [Abstract] |  |  |  |
Amortization of debt discount and issuance costs | $ 0.8 | $ 0.8 | $ 2.3 | $ 2.7
Amortization of deferred financing costs | $ 0.0 | $ 0.0 | $ 0.0 | $ 0.0

X
- Definition Amortization of Debt Issuance Cost and Discount + References No definition available. + Details
Name: | mgni_AmortizationOfDebtIssuanceCostAndDiscount
Namespace Prefix: | mgni_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_DebtDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of amortization of other deferred costs recognized in the income statement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Subparagraph (b) -SubTopic 10 -Topic 230 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-28 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(3)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2 + Details
Name: | us-gaap_OtherAmortizationOfDeferredCharges
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration