LOANS RECEIVABLE, NET AND RELATED ALLOWANCE FOR CREDIT LOSSES (Details) - Schedule of Loan Portfolio $ in Thousands	9 Months Ended
Jun. 30, 2024 USD ($)
One-to-Four Family Residential [Member]
One-to-four family residential
Term Loans Amortized Cost Basis by Origination Fiscal Year 2024	$ 22,560
Term Loans Amortized Cost Basis by Origination Fiscal Year 2023	42,570
Term Loans Amortized Cost Basis by Origination Fiscal Year 2022	31,739
Term Loans Amortized Cost Basis by Origination Fiscal Year 2021	26,279
Term Loans Amortized Cost Basis by Origination Fiscal Year 2020	30,473
Term Loans Amortized Cost Basis by Origination Fiscal Year Prior	85,099
Revolving Loans, Amortized Cost Basis	15
Revolving Loans, Converted to Term
Total	238,735
One-to-Four Family Residential [Member] \| Revolving Credit Facility [Member]
One-to-four family residential
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
One-to-Four Family Residential [Member] \| Performing Financial Instruments [Member]
One-to-four family residential
Term Loans Amortized Cost Basis by Origination Fiscal Year 2024	22,560
Term Loans Amortized Cost Basis by Origination Fiscal Year 2023	42,570
Term Loans Amortized Cost Basis by Origination Fiscal Year 2022	31,739
Term Loans Amortized Cost Basis by Origination Fiscal Year 2021	26,279
Term Loans Amortized Cost Basis by Origination Fiscal Year 2020	30,473
Term Loans Amortized Cost Basis by Origination Fiscal Year Prior	85,076
Revolving Loans, Amortized Cost Basis	15
Revolving Loans, Converted to Term
Total	238,712
One-to-Four Family Residential [Member] \| Nonperforming Financial Instruments [Member]
One-to-four family residential
Term Loans Amortized Cost Basis by Origination Fiscal Year 2024
Term Loans Amortized Cost Basis by Origination Fiscal Year 2023
Term Loans Amortized Cost Basis by Origination Fiscal Year 2022
Term Loans Amortized Cost Basis by Origination Fiscal Year 2021
Term Loans Amortized Cost Basis by Origination Fiscal Year 2020
Term Loans Amortized Cost Basis by Origination Fiscal Year Prior	23
Revolving Loans, Amortized Cost Basis
Revolving Loans, Converted to Term
Total	23
Commercial Real Estate [Member]
One-to-four family residential
Term Loans Amortized Cost Basis by Origination Fiscal Year 2024	68,190
Term Loans Amortized Cost Basis by Origination Fiscal Year 2023	84,363
Term Loans Amortized Cost Basis by Origination Fiscal Year 2022	70,444
Term Loans Amortized Cost Basis by Origination Fiscal Year 2021	65,281
Term Loans Amortized Cost Basis by Origination Fiscal Year 2020	29,922
Term Loans Amortized Cost Basis by Origination Fiscal Year Prior	124,936
Revolving Loans, Amortized Cost Basis	3,887
Revolving Loans, Converted to Term
Total	447,023
Commercial Real Estate [Member] \| Revolving Credit Facility [Member]
One-to-four family residential
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Construction And Land [Member]
One-to-four family residential
Term Loans Amortized Cost Basis by Origination Fiscal Year 2024	2,998
Term Loans Amortized Cost Basis by Origination Fiscal Year 2023	10,586
Term Loans Amortized Cost Basis by Origination Fiscal Year 2022	1,682
Term Loans Amortized Cost Basis by Origination Fiscal Year 2021
Term Loans Amortized Cost Basis by Origination Fiscal Year 2020	1,162
Term Loans Amortized Cost Basis by Origination Fiscal Year Prior	6,071
Revolving Loans, Amortized Cost Basis	1,594
Revolving Loans, Converted to Term
Total	24,093
Construction And Land [Member] \| Revolving Credit Facility [Member]
One-to-four family residential
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Home Equity Loan [Member]
One-to-four family residential
Term Loans Amortized Cost Basis by Origination Fiscal Year 2024	1,113
Term Loans Amortized Cost Basis by Origination Fiscal Year 2023	1,645
Term Loans Amortized Cost Basis by Origination Fiscal Year 2022	1,622
Term Loans Amortized Cost Basis by Origination Fiscal Year 2021	320
Term Loans Amortized Cost Basis by Origination Fiscal Year 2020	257
Term Loans Amortized Cost Basis by Origination Fiscal Year Prior	1,289
Revolving Loans, Amortized Cost Basis	17,351
Revolving Loans, Converted to Term	305
Total	23,902
Home Equity Loan [Member] \| Revolving Credit Facility [Member]
One-to-four family residential
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Home Equity Loan [Member] \| Performing Financial Instruments [Member]
One-to-four family residential
Term Loans Amortized Cost Basis by Origination Fiscal Year 2024	1,113
Term Loans Amortized Cost Basis by Origination Fiscal Year 2023	1,645
Term Loans Amortized Cost Basis by Origination Fiscal Year 2022	1,622
Term Loans Amortized Cost Basis by Origination Fiscal Year 2021	320
Term Loans Amortized Cost Basis by Origination Fiscal Year 2020	257
Term Loans Amortized Cost Basis by Origination Fiscal Year Prior	1,289
Revolving Loans, Amortized Cost Basis	17,351
Revolving Loans, Converted to Term	305
Total	23,902
Home Equity Loan [Member] \| Nonperforming Financial Instruments [Member]
One-to-four family residential
Term Loans Amortized Cost Basis by Origination Fiscal Year 2024
Term Loans Amortized Cost Basis by Origination Fiscal Year 2023
Term Loans Amortized Cost Basis by Origination Fiscal Year 2022
Term Loans Amortized Cost Basis by Origination Fiscal Year 2021
Term Loans Amortized Cost Basis by Origination Fiscal Year 2020
Term Loans Amortized Cost Basis by Origination Fiscal Year Prior
Revolving Loans, Amortized Cost Basis
Revolving Loans, Converted to Term
Total
Commercial Business [Member]
One-to-four family residential
Term Loans Amortized Cost Basis by Origination Fiscal Year 2024	1,619
Term Loans Amortized Cost Basis by Origination Fiscal Year 2023	520
Term Loans Amortized Cost Basis by Origination Fiscal Year 2022	2,577
Term Loans Amortized Cost Basis by Origination Fiscal Year 2021	1,674
Term Loans Amortized Cost Basis by Origination Fiscal Year 2020	844
Term Loans Amortized Cost Basis by Origination Fiscal Year Prior	2,718
Revolving Loans, Amortized Cost Basis	14,160
Revolving Loans, Converted to Term	244
Total	24,356
Commercial Business [Member] \| Revolving Credit Facility [Member]
One-to-four family residential
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Other [Member]
One-to-four family residential
Term Loans Amortized Cost Basis by Origination Fiscal Year 2024	58
Term Loans Amortized Cost Basis by Origination Fiscal Year 2023
Term Loans Amortized Cost Basis by Origination Fiscal Year 2022	54
Term Loans Amortized Cost Basis by Origination Fiscal Year 2021
Term Loans Amortized Cost Basis by Origination Fiscal Year 2020	11
Term Loans Amortized Cost Basis by Origination Fiscal Year Prior	1,771
Revolving Loans, Amortized Cost Basis	351
Revolving Loans, Converted to Term
Total	2,245
Other [Member] \| Revolving Credit Facility [Member]
One-to-four family residential
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Current period gross charge-offs
Other [Member] \| Performing Financial Instruments [Member]
One-to-four family residential
Term Loans Amortized Cost Basis by Origination Fiscal Year 2024	58
Term Loans Amortized Cost Basis by Origination Fiscal Year 2023
Term Loans Amortized Cost Basis by Origination Fiscal Year 2022	54
Term Loans Amortized Cost Basis by Origination Fiscal Year 2021
Term Loans Amortized Cost Basis by Origination Fiscal Year 2020	11
Term Loans Amortized Cost Basis by Origination Fiscal Year Prior	1,771
Revolving Loans, Amortized Cost Basis	351
Revolving Loans, Converted to Term
Total	2,245
Other [Member] \| Nonperforming Financial Instruments [Member]
One-to-four family residential
Term Loans Amortized Cost Basis by Origination Fiscal Year 2024
Term Loans Amortized Cost Basis by Origination Fiscal Year 2023
Term Loans Amortized Cost Basis by Origination Fiscal Year 2022
Term Loans Amortized Cost Basis by Origination Fiscal Year 2021
Term Loans Amortized Cost Basis by Origination Fiscal Year 2020
Term Loans Amortized Cost Basis by Origination Fiscal Year Prior
Revolving Loans, Amortized Cost Basis
Revolving Loans, Converted to Term
Total
Pass [Member] \| Commercial Real Estate [Member]
One-to-four family residential
Term Loans Amortized Cost Basis by Origination Fiscal Year 2024	68,190
Term Loans Amortized Cost Basis by Origination Fiscal Year 2023	84,363
Term Loans Amortized Cost Basis by Origination Fiscal Year 2022	68,019
Term Loans Amortized Cost Basis by Origination Fiscal Year 2021	65,281
Term Loans Amortized Cost Basis by Origination Fiscal Year 2020	29,922
Term Loans Amortized Cost Basis by Origination Fiscal Year Prior	124,692
Revolving Loans, Amortized Cost Basis	3,887
Revolving Loans, Converted to Term
Total	444,354
Pass [Member] \| Construction And Land [Member]
One-to-four family residential
Term Loans Amortized Cost Basis by Origination Fiscal Year 2024	2,998
Term Loans Amortized Cost Basis by Origination Fiscal Year 2023	10,586
Term Loans Amortized Cost Basis by Origination Fiscal Year 2022	1,682
Term Loans Amortized Cost Basis by Origination Fiscal Year 2021
Term Loans Amortized Cost Basis by Origination Fiscal Year 2020	1,162
Term Loans Amortized Cost Basis by Origination Fiscal Year Prior	4,374
Revolving Loans, Amortized Cost Basis	1,594
Revolving Loans, Converted to Term
Total	22,396
Pass [Member] \| Commercial Business [Member]
One-to-four family residential
Term Loans Amortized Cost Basis by Origination Fiscal Year 2024	1,619
Term Loans Amortized Cost Basis by Origination Fiscal Year 2023	520
Term Loans Amortized Cost Basis by Origination Fiscal Year 2022	2,577
Term Loans Amortized Cost Basis by Origination Fiscal Year 2021	1,674
Term Loans Amortized Cost Basis by Origination Fiscal Year 2020	844
Term Loans Amortized Cost Basis by Origination Fiscal Year Prior	2,718
Revolving Loans, Amortized Cost Basis	14,160
Revolving Loans, Converted to Term	244
Total	24,356
Special Mention [Member] \| Commercial Real Estate [Member]
One-to-four family residential
Term Loans Amortized Cost Basis by Origination Fiscal Year 2024
Term Loans Amortized Cost Basis by Origination Fiscal Year 2023
Term Loans Amortized Cost Basis by Origination Fiscal Year 2022	201
Term Loans Amortized Cost Basis by Origination Fiscal Year 2021
Term Loans Amortized Cost Basis by Origination Fiscal Year 2020
Term Loans Amortized Cost Basis by Origination Fiscal Year Prior	128
Revolving Loans, Amortized Cost Basis
Revolving Loans, Converted to Term
Total	329
Special Mention [Member] \| Construction And Land [Member]
One-to-four family residential
Term Loans Amortized Cost Basis by Origination Fiscal Year 2024
Term Loans Amortized Cost Basis by Origination Fiscal Year 2023
Term Loans Amortized Cost Basis by Origination Fiscal Year 2022
Term Loans Amortized Cost Basis by Origination Fiscal Year 2021
Term Loans Amortized Cost Basis by Origination Fiscal Year 2020
Term Loans Amortized Cost Basis by Origination Fiscal Year Prior
Revolving Loans, Amortized Cost Basis
Revolving Loans, Converted to Term
Total
Special Mention [Member] \| Commercial Business [Member]
One-to-four family residential
Term Loans Amortized Cost Basis by Origination Fiscal Year 2024
Term Loans Amortized Cost Basis by Origination Fiscal Year 2023
Term Loans Amortized Cost Basis by Origination Fiscal Year 2022
Term Loans Amortized Cost Basis by Origination Fiscal Year 2021
Term Loans Amortized Cost Basis by Origination Fiscal Year 2020
Term Loans Amortized Cost Basis by Origination Fiscal Year Prior
Revolving Loans, Amortized Cost Basis
Revolving Loans, Converted to Term
Total
Substandard [Member] \| Commercial Real Estate [Member]
One-to-four family residential
Term Loans Amortized Cost Basis by Origination Fiscal Year 2024
Term Loans Amortized Cost Basis by Origination Fiscal Year 2023
Term Loans Amortized Cost Basis by Origination Fiscal Year 2022	2,224
Term Loans Amortized Cost Basis by Origination Fiscal Year 2021
Term Loans Amortized Cost Basis by Origination Fiscal Year 2020
Term Loans Amortized Cost Basis by Origination Fiscal Year Prior	116
Revolving Loans, Amortized Cost Basis
Revolving Loans, Converted to Term
Total	2,340
Substandard [Member] \| Construction And Land [Member]
One-to-four family residential
Term Loans Amortized Cost Basis by Origination Fiscal Year 2024
Term Loans Amortized Cost Basis by Origination Fiscal Year 2023
Term Loans Amortized Cost Basis by Origination Fiscal Year 2022
Term Loans Amortized Cost Basis by Origination Fiscal Year 2021
Term Loans Amortized Cost Basis by Origination Fiscal Year 2020
Term Loans Amortized Cost Basis by Origination Fiscal Year Prior	1,697
Revolving Loans, Amortized Cost Basis
Revolving Loans, Converted to Term
Total	1,697
Substandard [Member] \| Commercial Business [Member]
One-to-four family residential
Term Loans Amortized Cost Basis by Origination Fiscal Year 2024
Term Loans Amortized Cost Basis by Origination Fiscal Year 2023
Term Loans Amortized Cost Basis by Origination Fiscal Year 2022
Term Loans Amortized Cost Basis by Origination Fiscal Year 2021
Term Loans Amortized Cost Basis by Origination Fiscal Year 2020
Term Loans Amortized Cost Basis by Origination Fiscal Year Prior
Revolving Loans, Amortized Cost Basis
Revolving Loans, Converted to Term
Total
Doubtful [Member] \| Commercial Real Estate [Member]
One-to-four family residential
Term Loans Amortized Cost Basis by Origination Fiscal Year 2024
Term Loans Amortized Cost Basis by Origination Fiscal Year 2023
Term Loans Amortized Cost Basis by Origination Fiscal Year 2022
Term Loans Amortized Cost Basis by Origination Fiscal Year 2021
Term Loans Amortized Cost Basis by Origination Fiscal Year 2020
Term Loans Amortized Cost Basis by Origination Fiscal Year Prior
Revolving Loans, Amortized Cost Basis
Revolving Loans, Converted to Term
Total
Doubtful [Member] \| Construction And Land [Member]
One-to-four family residential
Term Loans Amortized Cost Basis by Origination Fiscal Year 2024
Term Loans Amortized Cost Basis by Origination Fiscal Year 2023
Term Loans Amortized Cost Basis by Origination Fiscal Year 2022
Term Loans Amortized Cost Basis by Origination Fiscal Year 2021
Term Loans Amortized Cost Basis by Origination Fiscal Year 2020
Term Loans Amortized Cost Basis by Origination Fiscal Year Prior
Revolving Loans, Amortized Cost Basis
Revolving Loans, Converted to Term
Total
Doubtful [Member] \| Commercial Business [Member]
One-to-four family residential
Term Loans Amortized Cost Basis by Origination Fiscal Year 2024
Term Loans Amortized Cost Basis by Origination Fiscal Year 2023
Term Loans Amortized Cost Basis by Origination Fiscal Year 2022
Term Loans Amortized Cost Basis by Origination Fiscal Year 2021
Term Loans Amortized Cost Basis by Origination Fiscal Year 2020
Term Loans Amortized Cost Basis by Origination Fiscal Year Prior
Revolving Loans, Amortized Cost Basis
Revolving Loans, Converted to Term
Total

No definition available.

Name:	mgyr_OneToFourFamilyResidentialAbstract
Namespace Prefix:	mgyr_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of writeoff of financing receivable, charged against allowance for credit loss.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11B
-Subparagraph (c)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-11B

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 79
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-79

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-6

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-13

+ Details

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

- Definition

Amortized cost of financing receivable originated more than five years prior to current fiscal year. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 79
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-79

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-6

+ Details

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

- Definition

Amortized cost of financing receivable originated four years prior to current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amortized cost of financing receivable originated in current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amortized cost of financing receivable originated in fiscal year prior to current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amount of writeoff of financing receivable originated more than five years before current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amortized cost of financing receivable originated three years prior to current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amortized cost of financing receivable originated two years prior to current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amortized cost of financing receivable that can be withdrawn, repaid, and redrawn.

+ References

+ Details

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

- Definition

Amortized cost of revolving financing receivable converted to term loan.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 79
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-79

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-6A

+ Details

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

- Definition

Amount of writeoff of revolving financing receivable converted to term loan.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 79
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-79

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-6A

+ Details

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

- Definition

Amount of writeoff of financing receivable that can be withdrawn, repaid, and redrawn.

+ References

+ Details

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

- Definition

Amount of writeoff of financing receivable originated four years before current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amount of writeoff of financing receivable originated three years before current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amount of writeoff of financing receivable originated in current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amount of writeoff of financing receivable originated two years before current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amount of writeoff of financing receivable originated in fiscal year before current fiscal year. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amortized cost, before allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement and net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481990/310-10-45-13

Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-7A

Reference 3: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 29
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-29

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph a
-Subparagraph (1)
-Publisher SEC

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph a
-Subparagraph (2)
-Publisher SEC

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Regulation S-K (SK)
-Number 229
-Section 1404
-Paragraph a
-Publisher SEC

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 80
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-80

Reference 8: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 79
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479294/326-20-55-79

Reference 9: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479344/326-20-45-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3)(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-14

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-5

+ Details

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

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mgyr_OnetoFourFamilyResidentialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentPerformanceStatusAxis=us-gaap_PerformingFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentPerformanceStatusAxis=us-gaap_NonperformingFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mgyr_ConstructionAndLandMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_HomeEquityLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mgyr_CommercialBusinessMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mgyr_FinancingReceivableOtherMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_PassMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_SpecialMentionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_SubstandardMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_DoubtfulMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: