| (i) | Trade and other receivables |
Trade and other receivables are assessed at each reporting date to determine whether there is objective evidence that they are impaired. Trade or other receivables are impaired if objective evidence indicates that a loss event has occurred after the initial recognition of the receivable, and such loss event had a negative effect on the estimated future cash flows of that receivable that can be estimated reliably. Loss events include indications that a debtor is experiencing significant financial difficulty, default or delinquency in interest or principal payments, the probability that they will enter bankruptcy or other financial reorganization.
All receivables are assessed for specific impairment. Losses are recognized in profit or loss and reflected in an allowance account against receivables. When a subsequent event causes the amount of impairment loss to decrease, the decrease in impairment loss is reversed through profit or loss. No impairments or reversals of impairments were recognized in 2015, 2016 or 2017.
| (ii) | Intangible assets and leasehold improvements and equipment |
Assets that are subject to depreciation or amortization are reviewed for impairment whenever events or changes in circumstances indicate the carrying amount may not be recoverable. An impairment loss is recognized as the amount by which an asset’s carrying amount exceeds its recoverable amount. The recoverable amount is the higher of an asset’s fair value less costs of disposal and value in use. Non- financial assets that were previously impaired are reviewed for possible reversal of the impairment at each reporting date.