(4) Goodwill

          Goodwill represents the excess of the purchase price over the estimated fair value of net tangible and identifiable intangible assets acquired in business combinations. Our annual impairment assessment is performed as of October 1^st of each year, and an assessment is performed at other times if events or circumstances indicate it is more likely than not that the asset is impaired. During the three and six months ended June 30, 2011 and 2010, there were no indicators of impairment and no impairment loss was recorded to our goodwill.