SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND RECENTLY ADOPTED ACCOUNTING STANDARDS UPDATES ("ASU")	6 Months Ended
	Mar. 31, 2020
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND RECENTLY ADOPTED ACCOUNTING STANDARDS UPDATES (ASU)	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND RECENTLY ADOPTED ACCOUNTING STANDARDS UPDATES ("ASU") Significant accounting policies in effect and disclosed within the Company’s most recent audited consolidated financial statements as of September 30, 2019 remain substantially unchanged with the exception of the policies impacted by the adoption of noted ASUs below. Certain accounting policies were impacted by the recent events of the novel Coronavirus ("COVID-19"), and are discussed in Note 3. Significant Events. Adopted ASUs Leases -- The Company adopted ASU 2016-02, Leases (Topic 842), and subsequent related updates (collectively ASU 2016-02) on October 1, 2019, which requires lessees to recognize most leases on their balance sheet. Lessor accounting is largely unchanged. The ASU requires both quantitative and qualitative disclosures regarding key information about lease arrangements from both lessees and lessors. The Company elected the effective date transition method utilizing the adoption date as the first date of application of the revised guidance. As a result, prior period amounts have not been restated. Upon adoption, the Company elected certain transitional practical expedients offered through the guidance, including the 'package of practical expedients' whereby it did not reassess (i) whether any expired or existing contracts contain leases, (ii) the lease classification of any expired or existing leases, and (iii) initial direct costs for any existing leases, which resulted in the Company not recognizing a cumulative effect adjustment to retained earnings. Management evaluated Meta’s leasing contracts and activities and developed methodologies and processes to estimate and account for the right-of-use ("ROU") assets and lease liabilities for building leases based on the present value of future lease payments. On October 1, 2019, the Company recorded ROU assets and lease liabilities totaling $27.4 million and $28.6 million, respectively. The impact to capital ratios as a result of increased risk-weighted assets was immaterial. The adoption of this guidance did not result in a material change to lessee expense recognition. The changes to lessor accounting, as well as change in customer behavior driven by the adoption of these ASUs, impact the results of Meta’s lease financing businesses, including earlier recognition of expense due to a narrower definition of initial direct costs. As a lessee, the Company enters into contracts to lease real estate, information technology equipment and other various types of equipment. Leases that transfer substantially all of the benefits and risks of ownership to the Company are classified as finance leases, while all others are classified as operating leases. At lease commencement for buildings, a lease liability and ROU asset are calculated and recognized on both types of leases. The lease liability is equal to the present value of the future minimum lease payments. The ROU asset is equal to the lease liability, plus any initial direct costs and prepaid lease payments, less any lessor incentives received. Operating lease ROU assets are included in other assets and finance lease ROU assets are included in premises and equipment, net. The Company uses the appropriate term Federal Home Loan Bank ("FHLB") rate to determine the discount rate for the present value calculation of future minimum lease payments when an implicit rate is not known for a given lease. The lease term used in the calculation includes any options to extend that the Company is reasonably certain to exercise. The Company has elected to not recognize assets or liabilities on its balance sheet related to short-term leases. Subsequent to lease commencement, lease liabilities recorded for finance leases are measured using the effective interest rate method and the related ROU assets are amortized on a straight-line basis over the lease term. Interest expense and amortization expense are recorded separately on the Condensed Consolidated Statements of Operations in interest expense on borrowings and occupancy and equipment noninterest expense, respectively. At March 31, 2020, the Company had no finance lease ROU assets or lease liabilities. For operating leases, total lease cost is comprised of lease expense, short-term lease cost, variable lease cost and sublease income. Lease expense includes future minimum lease payments, which are recognized on a straight-line basis over the lease term, as well as common area maintenance charges, real estate taxes, insurance and other expenses, where applicable, which are expensed as incurred. Total lease cost for operating leases is recorded in occupancy and equipment noninterest expense. See Note 11. Operating Lease Right-of-Use Assets and Liabilities for further information. The Company also adopted the following ASUs on October 1, 2019, none of which had a material impact on the Company’s Condensed Consolidated Financial Statements: –ASU 2018-02, Income Statement -- Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. The Company elected to not reclassify tax effects stranded in accumulated other comprehensive income. –ASU 2018-09, Codification Improvements. ASUs to be Adopted ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. This ASU, along with subsequent ASUs published as clarifications to Topic 326, requires entities to replace the incurred loss impairment methodology with a methodology reflecting expected credit losses with considerations for a broader range of reasonable and supportable information to substantiate credit loss estimates and applies to loans, net investments in leases, debt securities, certain financial assets not accounted for at fair value through net income, and certain off-balance sheet credit exposures. This ASU is effective for the Company on October 1, 2020 and will be adopted on a modified retrospective basis through a cumulative-effect adjustment to retained earnings as of the beginning of the year of adoption. The Company's implementation process includes loss forecasting model development, evaluation of technical accounting topics, updates to the Company's allowance documentation, reporting processes and related internal controls, and operational readiness for the adoption of this ASU. The Company is utilizing a third-party vendor software for its credit loss estimate and is in process of reviewing model assumptions and other validation tasks. The Company is running its key processes parallel with current incurred loss models and will continue to refine its estimates throughout 2020 as CECL models are implemented and results are vetted. The amount of the change in the Company's allowance for loan and lease losses will be impacted by the portfolio composition and credit quality at the adoption date as well as economic conditions and forecasts at that time. At adoption, the Company expects to have a cumulative-effect adjustment to retained earnings for the change in the allowance for loan and lease losses, which will impact capital. Federal banking regulations permit institutions to limit the initial capital impact of this ASU by allowing a deferral of two years followed by three-year transition period to phase out the cumulative benefit to regulatory capital. An increase in the Company's allowance for loan and lease losses will result in a reduction to regulatory capital amounts and ratios; however, at this point of implementation, the Company is unable to provide a more precise estimate of the impact as results are still being vetted, including validation of model assumptions and estimation techniques as well as the build-out of operational and control structure supporting the end-to-end process. Other Upcoming ASUs - Refer to the Company’s most recently audited consolidated financial statements for the year ended September 30, 2019 for the latest update on other ASUs relevant to the Company and not yet adopted at March 31, 2020.