Basis of Presentation (Policies)	9 Months Ended
Mar. 31, 2022
Accounting Policies [Abstract]
Nature of Operations	Nature of Operations: PCSB Financial Corporation (the “Holding Company” and together with its direct and indirect subsidiaries, the “Company”) is a Maryland corporation organized by PCSB Bank (the “Bank”) for the purpose of acquiring all of the capital stock of the Bank issued in the Bank's conversion to stock ownership on April 20, 2017. At March 31, 2022, the significant assets of the Holding Company were the capital stock of the Bank, cash deposited in the Bank, and a loan to the PCSB Bank Employee Stock Ownership Plan (“ESOP”). The liabilities of the Holding Company were insignificant. The Company is subject to the financial reporting requirements of the Securities Exchange Act of 1934, as amended, and regulation and examination by the Board of Governors of the Federal Reserve System (the “Federal Reserve Board”) and the New York State Department of Financial Services (the “NYSDFS”). PCSB Bank is a community-oriented financial institution that provides financial services to individuals and businesses within its market area of Putnam, Southern Dutchess, Rockland and Westchester Counties in New York. The Bank is a state-chartered commercial bank, and its deposits are insured up to applicable limits by the Deposit Insurance Fund of the Federal Deposit Insurance Corporation (“FDIC”). The Bank’s primary regulators are the FDIC and the NYSDFS.
Basis of Presentation	Basis of Presentation: The unaudited consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”), and include the accounts of the Holding Company, the Bank and the Bank's two subsidiaries – PCSB Funding Corp. and UpCounty Realty Corp. (formerly PCSB Realty Ltd.). PCSB Funding Corp. is a real estate investment trust that holds certain mortgage assets. UpCounty Realty Corp. is a corporation that holds certain properties foreclosed upon by the Bank. All intercompany transactions and balances have been eliminated in consolidation. The unaudited consolidated financial statements contained herein reflect all normal recurring adjustments that are, in the opinion of management, necessary for a fair presentation of the results for the interim periods presented. Such adjustments are the only adjustments reflected in the consolidated financial statements contained herein. The results of operations for the current period presented are not necessarily indicative of the results of operations that may be expected for the entire current fiscal year. Certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission. The accompanying unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto for the year ended June 30, 2021, included in the Company's Annual Report on Form 10-K. Certain prior period amounts have been reclassified to conform to the current presentation. Reclassifications had no effect on prior period net income or equity.
Loans Held For Sale	Loans Receivable Held For Sale: Loans receivable held for sale are those loans which management has the intent to sell in the foreseeable future, and are carried at the lower of aggregate cost or market value. Net unrealized losses, if any, are recognized by a valuation allowance through a charge to noninterest income. Realized gains and losses on the sale of loans are recognized on the trade date and are determined by the difference between the sale proceeds and the carrying value of the loans. Loans may be sold with servicing rights released or retained. At the time of the sale, management records a servicing asset for the value of any retained servicing rights, which represents the present value of the differential between the contractual servicing fee and adequate compensation, defined as the fee a sub-servicer would require to assume the role of servicer, after considering the estimated effects of prepayments. Transfers of financial assets are accounted for as sales when control over the assets has been surrendered. Control over transferred assets is deemed to be surrendered when (1) the assets have been isolated from the Company, put presumptively beyond the reach of the transferor and its creditors, even in bankruptcy or other receivership, (2) the transferee obtains the right (free of conditions that constrain it from taking advantage of that right) to pledge or exchange the transferred assets, and (3) the transferor does not maintain effective control over the transferred assets through either (a) an agreement that both entitles and obligates the transferor to repurchase or redeem the assets before maturity or (b) the ability to unilaterally cause the holder to return specific assets, other than through a cleanup call.
Assets Held For Sale	Assets Held For Sale: Assets held for sale are those assets which management has the intent to sell in the foreseeable future, and are carried at the lower of aggregate cost or fair value, less estimated costs to sell, in the period in which the held for sale criteria are met and every subsequent period until the asset is sold. The carrying amount of the asset is adjusted for subsequent increases or decreases in its fair value, less estimated cost to sell, except that any subsequent increase cannot exceed the cumulative loss previously recognized. Such assets are not depreciated or amortized while they are classified as held for sale. Realized gains and losses on the sale of the asset is recognized when the asset is sold and is determined by the difference between the sale proceeds and the carrying value of the asset. Assets classified as held for sale totaled $1.5 million as of both March 31, 2022 and June 30, 2021 and are included in other assets on the consolidated balance sheet. During the nine months ended March 31, 2022, the Company sold $398,000 in assets held for sale resulting in gains on sale of $548,000.
Risks and Uncertainties	Risks and Uncertainties: The COVID-19 pandemic has created extensive disruptions to the global and U.S. economies and to the lives of individuals throughout the world. Governments, businesses, and the public have taken unprecedented actions to contain the spread of COVID-19 and to mitigate its effects, including vaccination mandates, quarantines, travel bans, shelter-in-place orders, closures of businesses and schools, fiscal and monetary stimulus, and legislation designed to deliver financial aid and other relief. While the scope, duration, and full effects of COVID-19 on the economy continue to evolve and are not fully known, the pandemic and the efforts to contain it have disrupted global economic activity, adversely affected the functioning of financial markets, impacted market interest rates, increased economic and market uncertainty, and disrupted trade and supply chains. Many of the emergency actions taken to mitigate the effects of the pandemic have since been reduced or eliminated, resulting in an improved local and national economic environment, however the ultimate financial impact of the pandemic on our borrowers, and therefore on our credit quality and financial performance, is still unknown at this time. The pandemic may continue to adversely impact consumers and several industries within our geographic footprint and impair the ability of the Company’s customers to fulfill their contractual obligations to the Company. This could cause the Company to experience a material adverse effect on our business operations, asset valuations, financial condition, and results of operations. Material adverse impacts may include, but are not limited to, the valuation impairments of the Company’s intangible assets, investments, loans receivable, or deferred tax assets. Additionally, it is reasonably possible that the Company’s allowance for loan loss estimate as of March 31, 2022 could change in the near term and could result in a material change to the Company’s provision for loan losses, earnings and capital.
Use of Estimates	Use of Estimates: To prepare financial statements in conformity with GAAP management makes estimates and assumptions based on available information. These estimates and assumptions affect the amounts reported in the financial statements and the disclosures provided, and actual results could differ.
Recent Accounting Pronouncements	The pronouncements discussed below are not intended to be an all-inclusive list, but rather only those pronouncements that the Company has determined could potentially have a material impact on its consolidated financial position and results of operations or on its disclosures. There were no accounting standards adopted in the current period. Future Application of Accounting Pronouncements Previously Issued In June 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-13 “Measurement of Credit Losses on Financial Instruments.” ASU 2016-13 which affects entities holding financial assets that are not accounted for at fair value through net income, including loans, debt securities, and other financial assets. The ASU requires financial assets measured at amortized cost basis to be presented at the net amount expected to be collected by recording an allowance for current expected credit losses. In October 2019, the FASB unanimously voted to delay the implementation of the standard for three years for certain companies, including small reporting companies (as defined by the SEC), non-SEC public companies and private companies. The Company currently qualifies as a small reporting company and is subject to the delayed implementation. Therefore, the amendments in this update will be effective for the Company for the fiscal year beginning on July 1, 2023, including interim periods within that fiscal year. The Company is actively working through the provisions of the Update. Management has established a steering committee which is identifying the methodologies and the additional data requirements necessary to implement the Update and has engaged a third-party software service provider to assist in the Company's implementation. On March 31, 2022 the FASB issued ASU 2022-02 "Financial Instruments - Credit Losses (Topic 326), Troubled Debt Restructurings and Vintage Disclosures." The ASU eliminates the current accounting guidance on troubled debt restructurings ("TDRs") for creditors, enhances disclosures for creditors with respect to loan refinancings and restructurings for borrowers experiencing financial difficulty and amends the guidance on vintage disclosures with respect to current period gross charge-offs. For entities that have not yet adopted ASU 2016-13, the amendments in ASU 2022-02 are effective upon the adoption of ASU 2016-13. Management is currently evaluating the impact that ASU 2016-13 and ASU 2022-02 will have on the Company’s consolidated financial position, results of operations and disclosures. The FASB issued ASU 2020-04 “Reference Rate Reform” and ASU 2021-01 “Reference Rate Reform Scope” which collectively address accounting considerations related to the expected discontinuation of LIBOR as a reference rate for financial contracts. These Updates provide optional expedients and exceptions for applying generally accepted accounting principles to contracts, hedging relationships and other transactions that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform (codified in ASC 848). They include optional expedients related to contract modifications that allow an entity to account for modifications (if certain criteria are met) as if the modifications were only minor (assets within the scope of ASC 310, Receivables), were not substantial (assets within the scope of ASC 470, Debt) and/or did not result in remeasurements or reclassifications (assets within the scope of ASC 842, Leases, and other Topics) of the existing contract. They also include optional expedients and exceptions for contract modifications and hedge accounting that apply to derivative instruments impacted by the market-wide discounting transition. The Updates also allow for a one-time election to sell, transfer, or both sell and transfer debt securities classified as held to maturity that reference a rate affected by reference rate reform and that are classified as held to maturity before January 1, 2020. The guidance in these ASUs are effective as of March 12, 2020 through December 31, 2022. The Company has not yet elected to apply the practical expedients contained in these Updates and does not expect significant impact to the consolidated financial statements upon adoption.

Basis of Presentation (Policies)

9 Months Ended

Mar. 31, 2022

Nature of Operations: PCSB Financial Corporation (the “Holding Company” and together with its direct and indirect subsidiaries, the “Company”) is a Maryland corporation organized by PCSB Bank (the “Bank”) for the purpose of acquiring all of the capital stock of the Bank issued in the Bank's conversion to stock ownership on April 20, 2017. At March 31, 2022, the significant assets of the Holding Company were the capital stock of the Bank, cash deposited in the Bank, and a loan to the PCSB Bank Employee Stock Ownership Plan (“ESOP”). The liabilities of the Holding Company were insignificant. The Company is subject to the financial reporting requirements of the Securities Exchange Act of 1934, as amended, and regulation and examination by the Board of Governors of the Federal Reserve System (the “Federal Reserve Board”) and the New York State Department of Financial Services (the “NYSDFS”).

PCSB Bank is a community-oriented financial institution that provides financial services to individuals and businesses within its market area of Putnam, Southern Dutchess, Rockland and Westchester Counties in New York. The Bank is a state-chartered commercial bank, and its deposits are insured up to applicable limits by the Deposit Insurance Fund of the Federal Deposit Insurance Corporation (“FDIC”). The Bank’s primary regulators are the FDIC and the NYSDFS.

Basis of Presentation

Basis of Presentation: The unaudited consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”), and include the accounts of the Holding Company, the Bank and the Bank's two subsidiaries – PCSB Funding Corp. and UpCounty Realty Corp. (formerly PCSB Realty Ltd.). PCSB Funding Corp. is a real estate investment trust that holds certain mortgage assets. UpCounty Realty Corp. is a corporation that holds certain properties foreclosed upon by the Bank. All intercompany transactions and balances have been eliminated in consolidation.

The unaudited consolidated financial statements contained herein reflect all normal recurring adjustments that are, in the opinion of management, necessary for a fair presentation of the results for the interim periods presented. Such adjustments are the only adjustments reflected in the consolidated financial statements contained herein. The results of operations for the current period presented are not necessarily indicative of the results of operations that may be expected for the entire current fiscal year. Certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission. The accompanying unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto for the year ended June 30, 2021, included in the Company's Annual Report on Form 10-K.

Certain prior period amounts have been reclassified to conform to the current presentation. Reclassifications had no effect on prior period net income or equity.

Loans Held For Sale

Loans Receivable Held For Sale: Loans receivable held for sale are those loans which management has the intent to sell in the foreseeable future, and are carried at the lower of aggregate cost or market value. Net unrealized losses, if any, are recognized by a valuation allowance through a charge to noninterest income. Realized gains and losses on the sale of loans are recognized on the trade date and are determined by the difference between the sale proceeds and the carrying value of the loans.

Loans may be sold with servicing rights released or retained. At the time of the sale, management records a servicing asset for the value of any retained servicing rights, which represents the present value of the differential between the contractual servicing fee and adequate compensation, defined as the fee a sub-servicer would require to assume the role of servicer, after considering the estimated effects of prepayments.

Transfers of financial assets are accounted for as sales when control over the assets has been surrendered. Control over transferred assets is deemed to be surrendered when (1) the assets have been isolated from the Company, put presumptively beyond the reach of the transferor and its creditors, even in bankruptcy or other receivership, (2) the transferee obtains the right (free of conditions that constrain it from taking advantage of that right) to pledge or exchange the transferred assets, and (3) the transferor does not maintain effective control over the transferred assets through either (a) an agreement that both entitles and obligates the transferor to repurchase or redeem the assets before maturity or (b) the ability to unilaterally cause the holder to return specific assets, other than through a cleanup call.

Assets Held For Sale

Assets Held For Sale: Assets held for sale are those assets which management has the intent to sell in the foreseeable future, and are carried at the lower of aggregate cost or fair value, less estimated costs to sell, in the period in which the held for sale

criteria are met and every subsequent period until the asset is sold. The carrying amount of the asset is adjusted for subsequent increases or decreases in its fair value, less estimated cost to sell, except that any subsequent increase cannot exceed the cumulative loss previously recognized. Such assets are not depreciated or amortized while they are classified as held for sale. Realized gains and losses on the sale of the asset is recognized when the asset is sold and is determined by the difference between the sale proceeds and the carrying value of the asset. Assets classified as held for sale totaled $1.5 million as of both March 31, 2022 and June 30, 2021 and are included in other assets on the consolidated balance sheet. During the nine months ended March 31, 2022, the Company sold $398,000 in assets held for sale resulting in gains on sale of $548,000.

Risks and Uncertainties

Risks and Uncertainties:

The COVID-19 pandemic has created extensive disruptions to the global and U.S. economies and to the lives of individuals throughout the world. Governments, businesses, and the public have taken unprecedented actions to contain the spread of COVID-19 and to mitigate its effects, including vaccination mandates, quarantines, travel bans, shelter-in-place orders, closures of businesses and schools, fiscal and monetary stimulus, and legislation designed to deliver financial aid and other relief. While the scope, duration, and full effects of COVID-19 on the economy continue to evolve and are not fully known, the pandemic and the efforts to contain it have disrupted global economic activity, adversely affected the functioning of financial markets, impacted market interest rates, increased economic and market uncertainty, and disrupted trade and supply chains.

Many of the emergency actions taken to mitigate the effects of the pandemic have since been reduced or eliminated, resulting in an improved local and national economic environment, however the ultimate financial impact of the pandemic on our borrowers, and therefore on our credit quality and financial performance, is still unknown at this time. The pandemic may continue to adversely impact consumers and several industries within our geographic footprint and impair the ability of the Company’s customers to fulfill their contractual obligations to the Company. This could cause the Company to experience a material adverse effect on our business operations, asset valuations, financial condition, and results of operations. Material adverse impacts may include, but are not limited to, the valuation impairments of the Company’s intangible assets, investments, loans receivable, or deferred tax assets. Additionally, it is reasonably possible that the Company’s allowance for loan loss estimate as of March 31, 2022 could change in the near term and could result in a material change to the Company’s provision for loan losses, earnings and capital.

Use of Estimates

Use of Estimates: To prepare financial statements in conformity with GAAP management makes estimates and assumptions based on available information. These estimates and assumptions affect the amounts reported in the financial statements and the disclosures provided, and actual results could differ.

Recent Accounting Pronouncements

The pronouncements discussed below are not intended to be an all-inclusive list, but rather only those pronouncements that the Company has determined could potentially have a material impact on its consolidated financial position and results of operations or on its disclosures.

There were no accounting standards adopted in the current period.

Future Application of Accounting Pronouncements Previously Issued

In June 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-13 “Measurement of Credit Losses on Financial Instruments.” ASU 2016-13 which affects entities holding financial assets that are not accounted for at fair value through net income, including loans, debt securities, and other financial assets. The ASU requires financial assets measured at amortized cost basis to be presented at the net amount expected to be collected by recording an allowance for current expected credit losses. In October 2019, the FASB unanimously voted to delay the implementation of the standard for three years for certain companies, including small reporting companies (as defined by the SEC), non-SEC public companies and private companies. The Company currently qualifies as a small reporting company and is subject to the delayed implementation. Therefore, the amendments in this update will be effective for the Company for the fiscal year beginning on July 1, 2023, including interim periods within that fiscal year. The Company is actively working through the provisions of the Update. Management has established a steering committee which is identifying the methodologies and the additional data requirements necessary to implement the Update and has engaged a third-party software service provider to assist in the Company's implementation. On March 31, 2022 the FASB issued ASU 2022-02 "Financial Instruments - Credit Losses (Topic 326), Troubled Debt Restructurings and Vintage Disclosures." The ASU eliminates the current accounting guidance on troubled debt restructurings ("TDRs") for creditors, enhances disclosures for creditors with respect to loan refinancings and restructurings for borrowers experiencing financial difficulty and amends the guidance on vintage disclosures with respect to current period gross charge-offs. For entities that have not yet adopted ASU 2016-13, the amendments in ASU

2022-02 are effective upon the adoption of ASU 2016-13. Management is currently evaluating the impact that ASU 2016-13 and ASU 2022-02 will have on the Company’s consolidated financial position, results of operations and disclosures.

The FASB issued ASU 2020-04 “Reference Rate Reform” and ASU 2021-01 “Reference Rate Reform Scope” which collectively address accounting considerations related to the expected discontinuation of LIBOR as a reference rate for financial contracts. These Updates provide optional expedients and exceptions for applying generally accepted accounting principles to contracts, hedging relationships and other transactions that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform (codified in ASC 848). They include optional expedients related to contract modifications that allow an entity to account for modifications (if certain criteria are met) as if the modifications were only minor (assets within the scope of ASC 310, Receivables), were not substantial (assets within the scope of ASC 470, Debt) and/or did not result in remeasurements or reclassifications (assets within the scope of ASC 842, Leases, and other Topics) of the existing contract. They also include optional expedients and exceptions for contract modifications and hedge accounting that apply to derivative instruments impacted by the market-wide discounting transition. The Updates also allow for a one-time election to sell, transfer, or both sell and transfer debt securities classified as held to maturity that reference a rate affected by reference rate reform and that are classified as held to maturity before January 1, 2020. The guidance in these ASUs are effective as of March 12, 2020 through December 31, 2022. The Company has not yet elected to apply the practical expedients contained in these Updates and does not expect significant impact to the consolidated financial statements upon adoption.