Litigation	3 Months Ended
Mar. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Litigation	Litigation In the ordinary course of our business, we are routinely made a defendant in or a party to pending or threatened legal actions or proceedings which, in some cases, seek substantial monetary damages from or other forms of relief against us. In our opinion, after consultation with legal counsel, we believe it unlikely that such actions or proceedings will have a material adverse effect on our financial condition, results of operations or liquidity. City of New York Notice of Determination By “Notice of Determination” dated September 14, 2010 and August 26, 2011, or the 2010 and 2011 Notices, the City of New York notified us of alleged tax deficiencies in the amount of $13.3 million, including interest and penalties, related to our 2006 through 2008 tax years. The deficiencies related to our operation of Fidata Service Corp., or Fidata, and Astoria Federal Mortgage Corp., or AF Mortgage, subsidiaries of Astoria Bank. We disagree with the assertion of the tax deficiencies. Hearings on the 2010 and 2011 Notices were held before the New York City Tax Appeals Tribunal, or the NYC Tax Appeals Tribunal, in March and April 2013. On October 29, 2014, the NYC Tax Appeals Tribunal issued a decision favorable to us canceling the 2010 and 2011 Notices. The City of New York appealed the decision of the NYC Tax Appeals Tribunal. The parties presented oral arguments on November 19, 2015 and are now awaiting a decision from the NYC Tax Appeals Tribunal. At this time, management believes it is more likely than not that we will succeed in defending against the City of New York’s appeal. Accordingly, no liability or reserve has been recognized in our consolidated statement of financial condition at March 31, 2016 with respect to this matter. By “Notice of Determination” dated November 19, 2014, or the 2014 Notice, the City of New York notified us of an alleged tax deficiency in the amount of $6.1 million, including interest and penalties, related to our 2009 and 2010 tax years, and by "Notice of Determination" dated August 5, 2015, or the 2015 Notice, the City of New York notified us of an alleged tax deficiency in the amount of $2.1 million, including interest and penalties, related to our 2011 through 2013 tax years. These deficiencies related to our operation of Fidata and AF Mortgage and the bases of the 2014 Notice and the 2015 Notice are substantially the same as that of the 2010 and 2011 Notices. We disagree with the assertion of the tax deficiencies, and we filed Petitions for Hearing with the City of New York on February 13, 2015 and September 9, 2015 to oppose the 2014 Notice and the 2015 Notice, respectively. By notice dated June 4, 2015, the NYC Tax Appeals Tribunal informed the parties that the proceedings relating to the 2014 Notice were adjourned pending the resolution of the proceedings with respect to the 2010 and 2011 Notices, the outcome of which may be determinative of some or all of the issues in this matter. On September 17, 2015, the NYC Tax Appeals Tribunal informed the parties that, barring the filing of an objection, the September 2015 Petition for Hearing would be consolidated with the February 2015 Petition and thus also adjourned pending resolution of the proceedings related to the 2010 and 2011 Notices. At this time, management believes it is more likely than not that we will succeed in refuting the City of New York’s position asserted in the 2014 Notice and the 2015 Notice. Accordingly, no liability or reserve has been recognized in our consolidated statement of financial condition at March 31, 2016 with respect to this matter. No assurance can be given as to whether or to what extent we will be required to pay the amount of the tax deficiencies asserted by the City of New York, whether additional tax will be assessed for years subsequent to 2013, that these matters will not be costly to oppose, that these matters will not have an impact on our financial condition or results of operations or that, ultimately, any such impact will not be material. Merger-related Litigation Following the announcement of the execution of the Merger Agreement, six lawsuits challenging the proposed Merger were filed in the Supreme Court of the State of New York, County of Nassau. These actions are captioned: (1) Sandra E. Weiss IRA v. Chrin, et al., Index No. 607132/2015 (filed November 4, 2015); (2) Raul v. Palleschi, et al., Index No. 607238/2015 (filed November 6, 2015); (3) Lowinger v. Redman, et al., Index No. 607268/2015 (filed November 9, 2015); (4) Minzer v. Astoria Fin. Corp., et al., Index No. 607358/2015 (filed November 12, 2015); (5) MSS 12-09 Trust v. Palleschi, et al., Index No. 607472/2015 (filed November 13, 2015); and (6) The Firemen’s Retirement System of St. Louis v. Keegan, et al., Index No. 607612/2015 (filed November 23, 2015). On January 15, 2016, the court consolidated the New York lawsuits under the caption In re Astoria Financial Corporation Shareholders Litigation, Index No. 607132/2015, and on January 29, 2016 the lead plaintiffs filed an amended consolidated complaint. In addition, a seventh lawsuit was filed challenging the proposed transaction in the Delaware Court of Chancery, captioned O’Connell v. Astoria Financial Corp., et al., Case No. 11928 (filed January 22, 2016). The plaintiff in this case filed an amended complaint on February 17, 2016. Each of the lawsuits is a putative class action filed on behalf of the stockholders of Astoria and names as defendants Astoria, its directors and NYCB, or collectively, the defendants. The various complaints generally allege that the directors of Astoria breached their fiduciary duties in connection with their approval of the Merger Agreement because they failed to properly value Astoria and to take steps to maximize value to Astoria’s public stockholders, resulting in inadequate merger consideration. The complaints further allege that the directors of Astoria approved the Merger through a flawed and unfair sales process, alleging the absence of a competitive sales process and that the process was tainted by certain alleged conflicts of interest on the part of the Astoria directors regarding certain personal and financial benefits they will receive upon consummation of the proposed transaction that public stockholders of Astoria will not receive. The complaints also variously allege that the Astoria directors breached their fiduciary duties because they improperly agreed to deal protection devices that allegedly preclude other bidders from making a successful competing offer for Astoria, including a no solicitation provision that allegedly prevents other buyers from participating in discussions which may lead to a superior proposal, a matching rights provision that allows NYCB to match any competing proposal in the event one is made and a provision that requires Astoria to pay NYCB a termination fee of $69.5 million under certain circumstances. In addition, the lawsuit filed in Delaware also alleges that Astoria’s directors breached their fiduciary duties by causing a false and materially misleading Form S-4 Registration Statement to be filed with the SEC. Each of the complaints further alleges that NYCB aided and abetted the alleged fiduciary breaches by the Astoria directors. Each of the actions seek, among other things, an order enjoining completion of the proposed Merger and an award of costs and attorneys’ fees. Certain of the actions also seek compensatory damages arising from the alleged breaches of fiduciary duty. The defendants believe these actions are without merit. Accordingly, no liability or reserve has been recognized in our consolidated statement of financial condition at March 31, 2016 with respect to these matters. On April 6, 2016, the defendants and lead plaintiffs for the consolidated New York lawsuits entered into a memorandum of understanding, or the MOU, which provides for the settlement of the New York lawsuits. The MOU contemplates, among other things, that Astoria will make certain supplemental disclosures relating to the Merger. Although the defendants deny the allegations made in the New York lawsuits (including the amended consolidated complaint) and believe that no supplemental disclosure is required under applicable laws, in order to avoid the burden and expense of further litigation, Astoria agreed to make such supplemental disclosures pursuant to the terms of the MOU. The supplemental disclosures were made available to Astoria’s shareholders on April 8, 2016 through a filing with the SEC by Astoria on a Current Report on Form 8-K. The settlement contemplated by the MOU is subject to confirmatory discovery and customary conditions, including court approval following notice to Astoria’s stockholders. A hearing will be scheduled at which the Supreme Court of the State of New York will consider the fairness, reasonableness and adequacy of the settlement. If the settlement is finally approved by the court, it will resolve and release all claims by stockholders of Astoria challenging any aspect of the Merger, the Merger Agreement, and any disclosure made in connection therewith, pursuant to terms that will be disclosed to stockholders prior to final approval of the settlement. There can be no assurance that the court will approve the settlement contemplated by the MOU. If the court does not approve the settlement, or if the settlement is otherwise disallowed, the proposed settlement as contemplated by the MOU may be terminated. If the MOU is terminated, no assurance can be given at this time that the litigation against us will be resolved in our favor, that this litigation will not be costly to defend, that this litigation will not have an impact on our financial condition or results of operations or that, ultimately, any such impact will not be material.

Litigation

In the ordinary course of our business, we are routinely made a defendant in or a party to pending or threatened legal actions or proceedings which, in some cases, seek substantial monetary damages from or other forms of relief against us. In our opinion, after consultation with legal counsel, we believe it unlikely that such actions or proceedings will have a material adverse effect on our financial condition, results of operations or liquidity.

City of New York Notice of Determination

By “Notice of Determination” dated September 14, 2010 and August 26, 2011, or the 2010 and 2011 Notices, the City of New York notified us of alleged tax deficiencies in the amount of $13.3 million, including interest and penalties, related to our 2006 through 2008 tax years. The deficiencies related to our operation of Fidata Service Corp., or Fidata, and Astoria Federal Mortgage Corp., or AF Mortgage, subsidiaries of Astoria Bank. We disagree with the assertion of the tax deficiencies. Hearings on the 2010 and 2011 Notices were held before the New York City Tax Appeals Tribunal, or the NYC Tax Appeals Tribunal, in March and April 2013. On October 29, 2014, the NYC Tax Appeals Tribunal issued a decision favorable to us canceling the 2010 and 2011 Notices. The City of New York appealed the decision of the NYC Tax Appeals Tribunal. The parties presented oral arguments on November 19, 2015 and are now awaiting a decision from the NYC Tax Appeals Tribunal. At this time, management believes it is more likely than not that we will succeed in defending against the City of New York’s appeal. Accordingly, no liability or reserve has been recognized in our consolidated statement of financial condition at March 31, 2016 with respect to this matter.

By “Notice of Determination” dated November 19, 2014, or the 2014 Notice, the City of New York notified us of an alleged tax deficiency in the amount of $6.1 million, including interest and penalties, related to our 2009 and 2010 tax years, and by "Notice of Determination" dated August 5, 2015, or the 2015 Notice, the City of New York notified us of an alleged tax deficiency in the amount of $2.1 million, including interest and penalties, related to our 2011 through 2013 tax years. These deficiencies related to our operation of Fidata and AF Mortgage and the bases of the 2014 Notice and the 2015 Notice are substantially the same as that of the 2010 and 2011 Notices. We disagree with the assertion of the tax deficiencies, and we filed Petitions for Hearing with the City of New York on February 13, 2015 and September 9, 2015 to oppose the 2014 Notice and the 2015 Notice, respectively. By notice dated June 4, 2015, the NYC Tax Appeals Tribunal informed the parties that the proceedings relating to the 2014 Notice were adjourned pending the resolution of the proceedings with respect to the 2010 and 2011 Notices, the outcome of which may be determinative of some or all of the issues in this matter. On September 17, 2015, the NYC Tax Appeals Tribunal informed the parties that, barring the filing of an objection, the September 2015 Petition for Hearing would be consolidated with the February 2015 Petition and thus also adjourned pending resolution of the proceedings related to the 2010 and 2011 Notices. At this time, management believes it is more likely than not that we will succeed in refuting the City of New York’s position asserted in the 2014 Notice and the 2015 Notice. Accordingly, no liability or reserve has been recognized in our consolidated statement of financial condition at March 31, 2016 with respect to this matter.

No assurance can be given as to whether or to what extent we will be required to pay the amount of the tax deficiencies asserted by the City of New York, whether additional tax will be assessed for years subsequent to 2013, that these matters will not be costly to oppose, that these matters will not have an impact on our financial condition or results of operations or that, ultimately, any such impact will not be material.

Merger-related Litigation

Following the announcement of the execution of the Merger Agreement, six lawsuits challenging the proposed Merger were filed in the Supreme Court of the State of New York, County of Nassau. These actions are captioned: (1) Sandra E. Weiss IRA v. Chrin, et al., Index No. 607132/2015 (filed November 4, 2015); (2) Raul v. Palleschi, et al., Index No. 607238/2015 (filed November 6, 2015); (3) Lowinger v. Redman, et al., Index No. 607268/2015 (filed November 9, 2015); (4) Minzer v. Astoria Fin. Corp., et al., Index No. 607358/2015 (filed November 12, 2015); (5) MSS 12-09 Trust v. Palleschi, et al., Index No. 607472/2015 (filed November 13, 2015); and (6) The Firemen’s Retirement System of St. Louis v. Keegan, et al., Index No. 607612/2015 (filed November 23, 2015). On January 15, 2016, the court consolidated the New York lawsuits under the caption In re Astoria Financial Corporation Shareholders Litigation, Index No. 607132/2015, and on January 29, 2016 the lead plaintiffs filed an amended consolidated complaint. In addition, a seventh lawsuit was filed challenging the proposed transaction in the Delaware Court of Chancery, captioned O’Connell v. Astoria Financial Corp., et al., Case No. 11928 (filed January 22, 2016). The plaintiff in this case filed an amended complaint on February 17, 2016. Each of the lawsuits is a putative class action filed on behalf of the stockholders of Astoria and names as defendants Astoria, its directors and NYCB, or collectively, the defendants.

The various complaints generally allege that the directors of Astoria breached their fiduciary duties in connection with their approval of the Merger Agreement because they failed to properly value Astoria and to take steps to maximize value to Astoria’s public stockholders, resulting in inadequate merger consideration. The complaints further allege that the directors of Astoria approved the Merger through a flawed and unfair sales process, alleging the absence of a competitive sales process and that the process was tainted by certain alleged conflicts of interest on the part of the Astoria directors regarding certain personal and financial benefits they will receive upon consummation of the proposed transaction that public stockholders of Astoria will not receive. The complaints also variously allege that the Astoria directors breached their fiduciary duties because they improperly agreed to deal protection devices that allegedly preclude other bidders from making a successful competing offer for Astoria, including a no solicitation provision that allegedly prevents other buyers from participating in discussions which may lead to a superior proposal, a matching rights provision that allows NYCB to match any competing proposal in the event one is made and a provision that requires Astoria to pay NYCB a termination fee of $69.5 million under certain circumstances. In addition, the lawsuit filed in Delaware also alleges that Astoria’s directors breached their fiduciary duties by causing a false and materially misleading Form S-4 Registration Statement to be filed with the SEC. Each of the complaints further alleges that NYCB aided and abetted the alleged fiduciary breaches by the Astoria directors.

Each of the actions seek, among other things, an order enjoining completion of the proposed Merger and an award of costs and attorneys’ fees. Certain of the actions also seek compensatory damages arising from the alleged breaches of fiduciary duty. The defendants believe these actions are without merit. Accordingly, no liability or reserve has been recognized in our consolidated statement of financial condition at March 31, 2016 with respect to these matters.

On April 6, 2016, the defendants and lead plaintiffs for the consolidated New York lawsuits entered into a memorandum of understanding, or the MOU, which provides for the settlement of the New York lawsuits. The MOU contemplates, among other things, that Astoria will make certain supplemental disclosures relating to the Merger. Although the defendants deny the allegations made in the New York lawsuits (including the amended consolidated complaint) and believe that no supplemental disclosure is required under applicable laws, in order to avoid the burden and expense of further litigation, Astoria agreed to make such supplemental disclosures pursuant to the terms of the MOU. The supplemental disclosures were made available to Astoria’s shareholders on April 8, 2016 through a filing with the SEC by Astoria on a Current Report on Form 8-K.

The settlement contemplated by the MOU is subject to confirmatory discovery and customary conditions, including court approval following notice to Astoria’s stockholders. A hearing will be scheduled at which the Supreme Court of the State of New York will consider the fairness, reasonableness and adequacy of the settlement. If the settlement is finally approved by the court, it will resolve and release all claims by stockholders of Astoria challenging any aspect of the Merger, the Merger Agreement, and any disclosure made in connection therewith, pursuant to terms that will be disclosed to stockholders prior to final approval of the settlement. There can be no assurance that the court will approve the settlement contemplated by the MOU. If the court does not approve the settlement, or if the settlement is otherwise disallowed, the proposed settlement as contemplated by the MOU may be terminated. If the MOU is terminated, no assurance can be given at this time that the litigation against us will be resolved in our favor, that this litigation will not be costly to defend, that this litigation will not have an impact on our financial condition or results of operations or that, ultimately, any such impact will not be material.