Commitments and Contingencies	6 Months Ended
Jun. 30, 2014
Commitments and Contingencies [Abstract]
Commitments and Contingencies	11. Commitments and Contingencies Legal Proceedings Durand Litigation On March 12, 2007, a putative class action suit captioned Jennifer A. Durand v. The Hanover Insurance Group, Inc., and The Allmerica Financial Cash Balance Pension Plan was filed in the United States District Court for the Western District of Kentucky. The named plaintiff, a former employee who received a lump sum distribution from the Company’s Cash Balance Plan (the “Plan”) at or about the time of her termination, claims that she and others similarly situated did not receive the appropriate lump sum distribution because in computing the lump sum, the Company and the Plan understated the accrued benefit in the calculation. The plaintiff claims that the Plan underpaid her distributions and those of similarly situated participants by failing to pay an additional so-called “whipsaw” amount reflecting the present value of an estimate of future interest credits from the date of the lump sum distribution to each participant’s retirement age of 65. The plaintiff filed an Amended Complaint adding two new named plaintiffs and additional claims on December 11, 2009. In response, the Company filed a Motion to Dismiss on January 30, 2010. In addition to the pending claim challenging the calculation of lump sum distributions, the Amended Complaint included: (a) a claim that the Plan failed to calculate participants’ account balances and lump sum payments properly because interest credits were based solely upon the performance of each participant’s selection from among various hypothetical investment options (as the Plan provided) rather than crediting the greater of that performance or the 30 year Treasury rate; (b) a claim that the 2004 Plan amendment, which changed interest crediting for all participants from the performance of participant’s investment selections to the 30 year Treasury rate, reduced benefits in violation of the Employee Retirement Income Security Act of 1974 (“ERISA”) for participants who had account balances as of the amendment date by not continuing to provide them performance-based interest crediting on those balances; and (c) claims against the Company for breach of fiduciary duty and ERISA notice requirements arising from the various interest crediting and lump sum distribution matters of which plaintiffs complain. On March 31, 2011, the District Court granted the Company and the Plan’s Motion to Dismiss on statute of limitations grounds the additional claims set forth in (a) and (b) above, however, in response to a motion for reconsideration, the Court allowed the new breach of fiduciary duty claim to stand, but only as to plaintiffs’ “whipsaw” claim that remained in the case. On June 22, 2012, the Company and the Plan filed a Partial Motion for Summary Judgment to dismiss the “whipsaw” claim of one of the named plaintiffs who received his lump sum distribution after December 31, 2003. On October 2, 2013, the Court granted the Company and the Plan’s Partial Motion for Summary Judgment and dismissed with prejudice the “whipsaw” claim of the named plaintiff who received a lump sum distribution after December 31, 2003 and the similar claims of the putative class members he sought to represent. On December 17, 2013, the Court entered an order certifying a class to bring “whipsaw” and related breach of fiduciary duty claims consisting of all persons who received a lump sum distribution between March 1, 1997 and December 31, 2003, and a subclass to bring such claims consisting of all persons who received lump sum distributions between March 1, 1997 and March 12, 2002. On December 17, 2013, the Court also granted plaintiffs’ motion for entry of a final order allowing an immediate appeal by the two named plaintiffs added in the Amended Complaint of their dismissed claims that the 2004 Plan amendment reduced benefits in violation of ERISA, and for one of them, that his post-2003 lump sum distribution should have been greater. On January 14, 2014, the Company filed a Motion to Alter or Amend the Court’s December 17, 2013 Order requesting that the Court reverse its order making the dismissed claims final and appealable or, in the alternative, stay merits discovery on the claims remaining in the district court pending resolution of the dismissed plaintiffs’ appeal. The Court denied this motion on April 30, 2014. At this time, the Company is unable to provide a reasonable estimate of the potential range of ultimate liability if the outcome of the suit is unfavorable. The extent to which any of the plaintiffs’ multiple theories of liability, some of which are overlapping and others of which are quite complex and novel, are accepted and upheld on appeal will significantly affect the Plan’s or the Company’s potential liability. The statute of limitations applicable to the class has not yet been finally determined and the extent of potential liability, if any, will depend on this final determination. In addition, assuming for these purposes that the plaintiffs prevail with respect to claims that benefits accrued or payable under the Plan were understated, then there are numerous possible theories and other variables upon which any revised calculation of benefits as requested under plaintiffs’ claims could be based. Any adverse judgment in this case against the Plan would be expected to create a liability for the Plan, with resulting effects on the Plan’s assets available to pay benefits. The Company’s future required funding of the Plan could also be impacted by such a liability. Other Matters The Company has been named a defendant in various other legal proceedings arising in the normal course of business. In addition, the Company is involved, from time to time, in examinations, investigations and proceedings by governmental and self-regulatory agencies. The potential outcome of any such action or regulatory proceedings in which the Company has been named a defendant or the subject of an inquiry or investigation, and its ultimate liability, if any, from such action or regulatory proceedings, is difficult to predict at this time. The ultimate resolutions of such proceedings are not expected to have a material effect on its financial position, although they could have a material effect on the results of operations for a particular quarter or annual period. Residual Markets The Company is required to participate in residual markets in various states, which generally pertain to high risk insureds, disrupted markets or lines of business or geographic areas where rates are regarded as excessive. The results of the residual markets are not subject to the predictability associated with the Company’s own managed business, and are significant to both the personal and commercial automobile lines of business, the workers’ compensation line of business, and the homeowners line of business.

11. Commitments and Contingencies

Legal Proceedings

Durand Litigation

On March 12, 2007, a putative class action suit captioned Jennifer A. Durand v. The Hanover Insurance Group, Inc., and The Allmerica Financial Cash Balance Pension Plan was filed in the United States District Court for the Western District of Kentucky. The named plaintiff, a former employee who received a lump sum distribution from the Company’s Cash Balance Plan (the “Plan”) at or about the time of her termination, claims that she and others similarly situated did not receive the appropriate lump sum distribution because in computing the lump sum, the Company and the Plan understated the accrued benefit in the calculation. The plaintiff claims that the Plan underpaid her distributions and those of similarly situated participants by failing to pay an additional so-called “whipsaw” amount reflecting the present value of an estimate of future interest credits from the date of the lump sum distribution to each participant’s retirement age of 65.

The plaintiff filed an Amended Complaint adding two new named plaintiffs and additional claims on December 11, 2009. In response, the Company filed a Motion to Dismiss on January 30, 2010. In addition to the pending claim challenging the calculation of lump sum distributions, the Amended Complaint included: (a) a claim that the Plan failed to calculate participants’ account balances and lump sum payments properly because interest credits were based solely upon the performance of each participant’s selection from among various hypothetical investment options (as the Plan provided) rather than crediting the greater of that performance or the 30 year Treasury rate; (b) a claim that the 2004 Plan amendment, which changed interest crediting for all participants from the performance of participant’s investment selections to the 30 year Treasury rate, reduced benefits in violation of the Employee Retirement Income Security Act of 1974 (“ERISA”) for participants who had account balances as of the amendment date by not continuing to provide them performance-based interest crediting on those balances; and (c) claims against the Company for breach of fiduciary duty and ERISA notice requirements arising from the various interest crediting and lump sum distribution matters of which plaintiffs complain. On March 31, 2011, the District Court granted the Company and the Plan’s Motion to Dismiss on statute of limitations grounds the additional claims set forth in (a) and (b) above, however, in response to a motion for reconsideration, the Court allowed the new breach of fiduciary duty claim to stand, but only as to plaintiffs’ “whipsaw” claim that remained in the case. On June 22, 2012, the Company and the Plan filed a Partial Motion for Summary Judgment to dismiss the “whipsaw” claim of one of the named plaintiffs who received his lump sum distribution after December 31, 2003. On October 2, 2013, the Court granted the Company and the Plan’s Partial Motion for Summary Judgment and dismissed with prejudice the “whipsaw” claim of the named plaintiff who received a lump sum distribution after December 31, 2003 and the similar claims of the putative class members he sought to represent. On December 17, 2013, the Court entered an order certifying a class to bring “whipsaw” and related breach of fiduciary duty claims consisting of all persons who received a lump sum distribution between March 1, 1997 and December 31, 2003, and a subclass to bring such claims consisting of all persons who received lump sum distributions between March 1, 1997 and March 12, 2002. On December 17, 2013, the Court also granted plaintiffs’ motion for entry of a final order allowing an immediate appeal by the two named plaintiffs added in the Amended Complaint of their dismissed claims that the 2004 Plan amendment reduced benefits in violation of ERISA, and for one of them, that his post-2003 lump sum distribution should have been greater. On January 14, 2014, the Company filed a Motion to Alter or Amend the Court’s December 17, 2013 Order requesting that the Court reverse its order making the dismissed claims final and appealable or, in the alternative, stay merits discovery on the claims remaining in the district court pending resolution of the dismissed plaintiffs’ appeal. The Court denied this motion on April 30, 2014.

At this time, the Company is unable to provide a reasonable estimate of the potential range of ultimate liability if the outcome of the suit is unfavorable. The extent to which any of the plaintiffs’ multiple theories of liability, some of which are overlapping and others of which are quite complex and novel, are accepted and upheld on appeal will significantly affect the Plan’s or the Company’s potential liability. The statute of limitations applicable to the class has not yet been finally determined and the extent of potential liability, if any, will depend on this final determination. In addition, assuming for these purposes that the plaintiffs prevail with respect to claims that benefits accrued or payable under the Plan were understated, then there are numerous possible theories and other variables upon which any revised calculation of benefits as requested under plaintiffs’ claims could be based. Any adverse judgment in this case against the Plan would be expected to create a liability for the Plan, with resulting effects on the Plan’s assets available to pay benefits. The Company’s future required funding of the Plan could also be impacted by such a liability.

Other Matters

The Company has been named a defendant in various other legal proceedings arising in the normal course of business. In addition, the Company is involved, from time to time, in examinations, investigations and proceedings by governmental and self-regulatory agencies. The potential outcome of any such action or regulatory proceedings in which the Company has been named a defendant or the subject of an inquiry or investigation, and its ultimate liability, if any, from such action or regulatory proceedings, is difficult to predict at this time. The ultimate resolutions of such proceedings are not expected to have a material effect on its financial position, although they could have a material effect on the results of operations for a particular quarter or annual period.

Residual Markets

The Company is required to participate in residual markets in various states, which generally pertain to high risk insureds, disrupted markets or lines of business or geographic areas where rates are regarded as excessive. The results of the residual markets are not subject to the predictability associated with the Company’s own managed business, and are significant to both the personal and commercial automobile lines of business, the workers’ compensation line of business, and the homeowners line of business.