Commitments and Contingencies	9 Months Ended
Sep. 30, 2016
Commitments and Contingencies [Abstract]
Commitments and Contingencies	12. 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 of our former life insurance and annuity business who received a lump sum distribution from the Company’s Cash Balance Plan (the “Plan”) at or about the time of her separation from the company, 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 (“whipsaw claim”). The plaintiff filed an Amended Complaint adding two new named plaintiffs and additional claims on December 11, 2009. Two of the three new claims set forth in the Amended Complaint were dismissed by the District Court, which action was upheld in November 2015 by the U.S. Court of Appeals, Sixth Circuit. The District Court, however, did allow to stand the portion of the Amended Complaint which set forth claims against the Company for breach of fiduciary duty and failure to meet notice requirements arising under the Employee Retirement Income Security Act of 1974 (“ERISA”) from the various interest crediting and lump sum distribution matters of which plaintiffs complain, but only as to plaintiffs’ “whipsaw” claim that remained in the case. 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. The Company filed a summary judgment motion, prior to the decision on the appeal, that was based on the statute of limitations and seeks to dismiss the subclass of plaintiffs who received lump sum distributions prior to March 13, 2002. This summary judgment motion has been stayed pending additional discovery. 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 statute of limitations applicable to the sub-class consisting of all persons who received lump sum distributions between March 1, 1997 and March 12, 2002 has not yet been finally determined, and the extent of potential liability, if any, will depend on this 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 and the workers’ compensation line of business.

12. 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 of our former life insurance and annuity business who received a lump sum distribution from the Company’s Cash Balance Plan (the “Plan”) at or about the time of her separation from the company, 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 (“whipsaw claim”).

The plaintiff filed an Amended Complaint adding two new named plaintiffs and additional claims on December 11, 2009. Two of the three new claims set forth in the Amended Complaint were dismissed by the District Court, which action was upheld in November 2015 by the U.S. Court of Appeals, Sixth Circuit. The District Court, however, did allow to stand the portion of the Amended Complaint which set forth claims against the Company for breach of fiduciary duty and failure to meet notice requirements arising under the Employee Retirement Income Security Act of 1974 (“ERISA”) from the various interest crediting and lump sum distribution matters of which plaintiffs complain, but only as to plaintiffs’ “whipsaw” claim that remained in the case. 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. The Company filed a summary judgment motion, prior to the decision on the appeal, that was based on the statute of limitations and seeks to dismiss the subclass of plaintiffs who received lump sum distributions prior to March 13, 2002. This summary judgment motion has been stayed pending additional discovery.

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 statute of limitations applicable to the sub-class consisting of all persons who received lump sum distributions between March 1, 1997 and March 12, 2002 has not yet been finally determined, and the extent of potential liability, if any, will depend on this 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 and the workers’ compensation line of business.