Goodwill
Goodwill represents the excess of the purchase price over the fair value of identifiable net assets upon acquisition of a business. On the acquisition date goodwill is allocated to the reporting unit expected to benefit from the acquisition. The carrying value of goodwill, which is not amortized, is assessed for impairment annually, or more frequently if events or changes in circumstances arise that suggest goodwill may be impaired. The Company's annual review of goodwill is performed in the fourth quarter, on the October 1 balance.
The Company first assesses qualitative factors, including, but not limited to economic, market, and industry conditions, the reporting unit's overall financial performance and events such as notable changes in management or customers. If the qualitative assessment indicates that it is more likely than not that the fair value of the reporting unit is less than its carrying value, a quantitative assessment is undertaken. The quantitative assessment is a comparison of the reporting unit's carrying value and fair value. The reporting unit's fair value is defined as the price expected to be received if it was sold in an orderly transaction between market participants. It is determined based on pre-tax discounted cash flows that reflect management's best estimates of the time value of money and risks specific to the reporting unit and its assets. If the carrying value of the reporting unit, including goodwill, exceeds its fair value, an impairment is recognized, measured at the amount by which the reporting unit's carrying value exceeds its fair value.
Intangible assets
Intangible assets with finite lives, consisting primarily of customer contracts, customer relationships and favourable leases are amortized on a straight-line basis over their estimated useful lives of up to 22 years. When there is a change in the estimated useful life of an intangible asset with a finite life, amortization is adjusted prospectively. An intangible asset with a finite life is assessed for impairment whenever events or circumstances indicate that its carrying amount may not be recoverable.
Intangible assets with indefinite useful lives are primarily trackage rights that are expected to generate cash flows indefinitely. They are not amortized but are tested for impairment annually, or more frequently if events or changes in circumstances indicate they may be impaired.
When assessing an intangible asset for impairment, if the undiscounted cash flows indicate that its carrying amount may not be recoverable, an impairment loss will be recognized for the amount that its carrying amount exceeds its fair value, determined based on pre-tax discounted cash flows that reflect management's best estimates of the time value of money and risks specific to the asset.