Impact of Recent Accounting Standards and Interpretations (Policies)	3 Months Ended
Mar. 31, 2017
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Impact of Recent Accounting Standards and Interpretations	In May 2014, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, 2014-09, “Revenue from Contracts with Customers (Topic 606),” to replace all current U.S. GAAP guidance on this topic and eliminate industry-specific guidance, providing a unified model to determine when and how revenue is recognized. We will adopt this guidance in the first quarter of 2018 using the modified retrospective method with a cumulative-effect adjustment to opening retained earnings, as appropriate. Our revenue is comprised of net interest income on financial assets and financial liabilities and non-interest income. The scope of ASU 2014-09 explicitly excludes net interest income as well as other revenues associated with financial assets and liabilities, including loans, leases, securities and derivatives. Accordingly, the majority of our revenues will not be affected. Other recurring revenue streams are within the scope of ASU 2014-09, including revenues associated with certain products and services offered by our banking and insurance businesses. Our preliminary analysis suggests that adoption of ASU 2014-09 is not expected to have a material impact on our financial condition or results of operations. In January 2016, the FASB issued ASU 2016-01, “Financial Instruments - Overall (Subtopic 825-10) - Recognition and Measurement of Financial Assets and Financial Liabilities.” The amendments in ASU 2016-01 require all equity investments to be measured at fair value, with changes in the fair value recognized through net income (other than those accounted for under the equity method of accounting or those resulting in consolidation of the investee). The amendments in ASU 2016-01 also require an entity to present separately in “other comprehensive income” the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. In addition, the amendments in ASU 2016-01 eliminate the requirement to disclose the method(s) and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheet for public business entities. ASU 2016-01 is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The adoption of ASU 2016-01 is not expected to have a material effect on our consolidated statements of condition or results of operations. In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842),” which requires lessees to recognize most leases, including operating leases, on-balance sheet via a right-to-use asset that will be depreciated over the term of the lease and a lease liability measured on a discounted basis. This will require many entities including Astoria Bank to include more existing leases on-balance sheet. We have identified several areas that are within the scope of ASU 2016-02, including Astoria Bank's contracts with respect to leased real estate and office equipment. We continue to evaluate the impact of ASU 2016-02, including determining whether other contracts exist that are deemed to be in scope. As such, no conclusions have yet been reached regarding the potential impact of adoption on our financial condition, results of operations or cash flows. ASU 2016-02 is effective for public companies for fiscal years beginning after December 15, 2018, including interim period within those fiscal years. In June 2016, the FASB issued ASU 2016-13, “Financial Instruments-Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments,” which require a financial asset measured at amortized cost to be presented at the net amount expected to be collected. The measurement of expected credit losses is to be based on information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. This measurement is to take place at the time an asset is first added to the balance sheet and periodically thereafter. This differs significantly from the “incurred loss” methodology for recognizing credit losses required under current GAAP, which delays recognition until it is probable a loss has been incurred. The new standard is effective for public companies for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. We are currently evaluating the impact of ASU 2016-13 on our accounting, but we expect to recognize a one-time cumulative-effect adjustment to our allowance for loan losses as of the beginning of the first reporting period in which the new standard becomes effective. While we have begun the process of compiling historical loss data by loan category, we cannot yet determine the magnitude of any such one-time cumulative adjustment or of the overall impact of the new standard on our financial condition or results of operations. Further, to date, no guidance has been issued by either our or Astoria Bank’s primary regulator with respect to how the impact of ASU 2016-13 is to be treated for regulatory capital purposes. In January 2017, the FASB issued ASU 2017-04, “Intangibles-Goodwill and Other (Topic 350), Simplifying the Test for Goodwill Impairment,” as an update for entities that perform an annual goodwill impairment test. This update eliminates Step 2 from the goodwill impairment test and allows companies to measure impairment by comparing the fair value of a reporting unit with its carrying amount. Thus, an entity will no longer determine goodwill impairment by calculating the implied fair value of goodwill by assigning the fair value of reporting unit to all of its assets and liabilities as if that reporting unit had been acquired in a business combination. The new standard is effective for public companies for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, with early adoption permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. We continue to evaluate the impact of ASU 2017-04, but the adoption is not expected to have a material effect on our consolidated statements of condition or results of operations.

In May 2014, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, 2014-09, “Revenue from Contracts with Customers (Topic 606),” to replace all current U.S. GAAP guidance on this topic and eliminate industry-specific guidance, providing a unified model to determine when and how revenue is recognized. We will adopt this guidance in the first quarter of 2018 using the modified retrospective method with a cumulative-effect adjustment to opening retained earnings, as appropriate. Our revenue is comprised of net interest income on financial assets and financial liabilities and non-interest income. The scope of ASU 2014-09 explicitly excludes net interest income as well as other revenues associated with financial assets and liabilities, including loans, leases, securities and derivatives. Accordingly, the majority of our revenues will not be affected. Other recurring revenue streams are within the scope of ASU 2014-09, including revenues associated with certain products and services offered by our banking and insurance businesses. Our preliminary analysis suggests that adoption of ASU 2014-09 is not expected to have a material impact on our financial condition or results of operations.

In January 2016, the FASB issued ASU 2016-01, “Financial Instruments - Overall (Subtopic 825-10) - Recognition and Measurement of Financial Assets and Financial Liabilities.” The amendments in ASU 2016-01 require all equity investments to be measured at fair value, with changes in the fair value recognized through net income (other than those accounted for under the equity method of accounting or those resulting in consolidation of the investee). The amendments in ASU 2016-01 also require an entity to present separately in “other comprehensive income” the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. In addition, the amendments in ASU 2016-01 eliminate the requirement to disclose the method(s) and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheet for public business entities. ASU 2016-01 is effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The adoption of ASU 2016-01 is not expected to have a material effect on our consolidated statements of condition or results of operations.

In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842),” which requires lessees to recognize most leases, including operating leases, on-balance sheet via a right-to-use asset that will be depreciated over the term of the lease and a lease liability measured on a discounted basis. This will require many entities including Astoria Bank to include more existing leases on-balance sheet. We have identified several areas that are within the scope of ASU 2016-02, including Astoria Bank's contracts with respect to leased real estate and office equipment. We continue to evaluate the impact of ASU 2016-02, including determining whether other contracts exist that are deemed to be in scope. As such, no conclusions have yet been reached regarding the potential impact of adoption on our financial condition, results of operations or cash flows. ASU 2016-02 is effective for public companies for fiscal years beginning after December 15, 2018, including interim period within those fiscal years.

In June 2016, the FASB issued ASU 2016-13, “Financial Instruments-Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments,” which require a financial asset measured at amortized cost to be presented at the net amount expected to be collected. The measurement of expected credit losses is to be based on information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. This measurement is to take place at the time an asset is first added to the balance sheet and periodically thereafter. This differs significantly from the “incurred loss” methodology for recognizing credit losses required under current GAAP, which delays recognition until it is probable a loss has been incurred. The new standard is effective for public companies for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. We are currently evaluating the impact of ASU 2016-13 on our accounting, but we expect to recognize a one-time cumulative-effect adjustment to our allowance for loan losses as of the beginning of the first reporting period in which the new standard becomes effective. While we have begun the process of compiling historical loss data by loan category, we cannot yet determine the magnitude of any such one-time cumulative adjustment or of the overall impact of the new standard on our financial condition or results of operations. Further, to date, no guidance has been issued by either our or Astoria Bank’s primary regulator with respect to how the impact of ASU 2016-13 is to be treated for regulatory capital purposes.

In January 2017, the FASB issued ASU 2017-04, “Intangibles-Goodwill and Other (Topic 350), Simplifying the Test for Goodwill Impairment,” as an update for entities that perform an annual goodwill impairment test. This update eliminates Step 2 from the goodwill impairment test and allows companies to measure impairment by comparing the fair value of a reporting unit with its carrying amount. Thus, an entity will no longer determine goodwill impairment by calculating the implied fair value of goodwill by assigning the fair value of reporting unit to all of its assets and liabilities as if that reporting unit had been acquired in a business combination. The new standard is effective for public companies for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, with early adoption permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. We continue to evaluate the impact of ASU 2017-04, but the adoption is not expected to have a material effect on our consolidated statements of condition or results of operations.