XML 61 R50.htm IDEA: XBRL DOCUMENT
v3.25.3

Loans - Amortized cost basis of loans on nonaccrual status and the related allowance (Details) - USD ($) | 12 Months Ended |
--- | --- | ---
Jun. 30, 2025 | Sep. 30, 2025
Amortized cost basis of loans on nonaccrual status and the related allowance |  |
Nonaccrual Balance |  | $ 190,013
Nonaccrual loans Without Allowance For Credit Loss | $ 66,645 | 190,013
Loans Past Due Over 90 Days Still Accruing | 0 | 0
Interest Income | 2,492 |
One-to-four-family residential |  |
Amortized cost basis of loans on nonaccrual status and the related allowance |  |
Nonaccrual loans Without Allowance For Credit Loss | 66,645 |
Interest Income | $ 2,492 |
Residential | One-to-four-family residential |  |
Amortized cost basis of loans on nonaccrual status and the related allowance |  |
Nonaccrual Balance |  | 190,013
Nonaccrual loans Without Allowance For Credit Loss |  | $ 190,013

X
- Definition Amount excluding accrued interest, of allowance for credit loss on financing receivable on nonaccrual status. Excludes net investment in lease. + References No definition available. + Details
Name: | mara_FinancingReceivableExcludingAccruedInterestAllowancesForCreditLossesNonaccrual
Namespace Prefix: | mara_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amortized cost excluding accrued interest, of financing receivable on nonaccrual status. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 16 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-16 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrual
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Definition Amortized cost excluding accrued interest, of financing receivable on nonaccrual status with no allowance for credit loss. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 16 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-16 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrualNoAllowance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of interest income on financing receivable on nonaccrual status. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 16 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-16 + Details
Name: | us-gaap_FinancingReceivableNonaccrualInterestIncome
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mara_OneToFourFamilyResidentialMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |