extrusions ( afe ) , which are all included in the engineered products and solutions segment , global rolled products , and building and construction systems , which is included in the transportation and construction solutions segment . the estimated fair value for five of the six reporting units exceeded its respective carrying value , resulting in no impairment . however , the estimated fair value of afe was lower than its carrying value . as such , in the fourth quarter of 2017 , arconic recorded an impairment for the full amount of goodwill in the afe reporting unit of $ 719 . the decrease in the afe fair value was primarily due to unfavorable performance that is impacting operating margins and a higher discount rate due to an increase in the risk-free rate of return , while the carrying value increased compared to prior year . goodwill impairment tests in 2016 and 2015 indicated that goodwill was not impaired for any of the company 2019s reporting units , except for the soft alloy extrusion business in brazil which is included in the transportation and construction solutions segment . in the fourth quarter of 2015 , for the soft alloy extrusion business in brazil , the estimated fair value as determined by the dcf model was lower than the associated carrying value of its reporting unit 2019s goodwill . as a result , management determined that the implied fair value of the reporting unit 2019s goodwill was zero . arconic recorded a goodwill impairment of $ 25 in 2015 . the impairment of goodwill resulted from headwinds from the downturn in the brazilian economy and the continued erosion of gross margin despite the execution of cost reduction strategies . as a result of the goodwill impairment , there is no goodwill remaining for the reporting unit . other intangible assets . intangible assets with indefinite useful lives are not amortized while intangible assets with finite useful lives are amortized generally on a straight-line basis over the periods benefited . the following table details the weighted- average useful lives of software and other intangible assets by reporting segment ( numbers in years ) : .
what is the difference between the weighted- average useful lives of software for the global rolled products segment and the transportation and construction solutions one?
revenue recognition . arconic recognizes revenues when title , ownership , and risk of loss pass to the customer , all of which occurs upon shipment or delivery of the product and is based on the applicable shipping terms . the shipping terms vary across all businesses and depend on the product , the country of origin , and the type of transportation ( truck , train , or vessel ) . in certain circumstances , arconic receives advanced payments from its customers for product to be delivered in future periods . these advanced payments are recorded as deferred revenue until the product is delivered and title and risk of loss have passed to the customer in accordance with the terms of the contract . deferred revenue is included in other current liabilities and other noncurrent liabilities and deferred credits on the accompanying consolidated balance sheet . environmental matters . expenditures for current operations are expensed or capitalized , as appropriate . expenditures relating to existing conditions caused by past operations , which will not contribute to future revenues , are expensed . liabilities are recorded when remediation costs are probable and can be reasonably estimated . the liability may include costs such as site investigations , consultant fees , feasibility studies , outside contractors , and monitoring expenses . estimates are generally not discounted or reduced by potential claims for recovery . claims for recovery are recognized when probable and as agreements are reached with third parties . the estimates also include costs related to other potentially responsible parties to the extent that arconic has reason to believe such parties will not fully pay their proportionate share . the liability is continuously reviewed and adjusted to reflect current remediation progress , prospective estimates of required activity , and other factors that may be relevant , including changes in technology or regulations . litigation matters . for asserted claims and assessments , liabilities are recorded when an unfavorable outcome of a matter is deemed to be probable and the loss is reasonably estimable . management determines the likelihood of an unfavorable outcome based on many factors such as the nature of the matter , available defenses and case strategy , progress of the matter , views and opinions of legal counsel and other advisors , applicability and success of appeals processes , and the outcome of similar historical matters , among others . once an unfavorable outcome is deemed probable , management weighs the probability of estimated losses , and the most reasonable loss estimate is recorded . if an unfavorable outcome of a matter is deemed to be reasonably possible , then the matter is disclosed and no liability is recorded . with respect to unasserted claims or assessments , management must first determine that the probability that an assertion will be made is likely , then , a determination as to the likelihood of an unfavorable outcome and the ability to reasonably estimate the potential loss is made . legal matters are reviewed on a continuous basis to determine if there has been a change in management 2019s judgment regarding the likelihood of an unfavorable outcome or the estimate of a potential loss . income taxes . the provision for income taxes is determined using the asset and liability approach of accounting for income taxes . under this approach , the provision for income taxes represents income taxes paid or payable ( or received or receivable ) .