Change in Fair Value of Prior Year Awards that Forfeited During Year [Member] Michael L. Battles [Member] Change in Fair Value of Prior Year Awards Unvested as of Year-End [Member] Alan S. McKim [Member] Eric W. Gerstenberg [Member] Change in Fair Value of Prior Year Awards that Vested During Year [Member] Change in Fair Value of Awards Granted During Year and Outstanding and Unvested as of Year-End [Member] Less: Grant Date Fair Value of Stock Awards (from Summary Compensation Table) [Member]