|12 Months Ended|
Dec. 31, 2017
|Goodwill and Intangible Assets Disclosure [Abstract]|
The following table summarizes acquired intangible assets as follows:
Amortization is computed on the straight-line method for financial reporting purposes, with the exception of backlog, which is amortized based on the expected realization period of the acquired backlog. Amortization expense for intangibles was $12.3 million, $10.8 million and $11.3 million for 2017, 2016 and 2015, respectively.
Based upon acquired intangible assets at December 31, 2017, amortization expense for each of the next five years is estimated to be:
The entire disclosure for all or part of the information related to intangible assets.
Reference 1: http://www.xbrl.org/2003/role/presentationRef