Note 8.    Goodwill and Intangible Assets

Goodwill represents the excess of the purchase price of an acquired business over the estimated fair values of the underlying net tangible and intangible assets. Goodwill consisted of the following:

 

 

During the year ended December 31, 2015, the following key items impacted goodwill:

During the year ended December 31, 2014, the following key items impacted goodwill:

Goodwill is allocated to the Company’s one reportable segment which is its only reporting unit.

The Company’s intangible assets consisted of the following:

 

 

At December 31, 2015, the weighted-average amortization period for the intangible assets is 10.3 years. At December 31, 2015, the weighted-average amortization periods for customer lists, patents and technology and trademarks are 10.5, 9.3 and 7.3 years, respectively.

During the quarter ended December 31, 2015, the Company noted anticipated revenue from SENS to be lower than originally forecasted. The fair value of trademark and technology intangible assets are determined based on the “relief from royalty method”, under the income approach, which is a valuation technique that provides an estimate of the fair value of an asset based on the costs savings that are available through ownership of the asset by the avoidance of paying royalties to license the use of the assets from another owner. This method is comprised of applying an estimated royalty rate to projected revenues. The estimated fair value of the customer lists is determined using the “excess earnings method” under the income approach, which represents the total income to be generated by the asset. Some of the more significant assumptions inherent in the development of those asset valuations include the projected revenue associated with the asset, the appropriate discount rate to select in order to measure the risk inherent in each future cash flow stream, the assessment of each asset’s life cycle, as well as other factors. As a result, and in accordance with FASB ASC 360 “Impairment and Disposal of Long-Lived Assets,” the Company adjusted the carrying amount of the SENS trademark, technology and customer list intangible assets to a fair value of $0, $30 and $280, respectively. As a result, the Company recorded an impairment charge of $564 as part of depreciation and amortization in the consolidated statement of operations for the year ended December 31, 2015.

Amortization expense for the years ended December 31, 2015, 2014 and 2013 was $10,636, $2,795 and $1,385, respectively.

Estimated amortization expense for intangible assets is as follows: