ImpairmentA review for indicators of impairment is carried out at each reporting date, with the recoverable amount being estimated where such indicators exist. Where the carrying value exceeds the recoverable amount, the asset is impaired accordingly. Prior impairments are also reviewed for possible reversal at each reporting date.When it is not possible to estimate the recoverable amount of an individual asset, an estimate is made of the recoverable amount of the cash-generating unit to which the asset belongs. The cash-generating unit is the smallest identifiable group of assets that includes the asset and generates cash inflows that are largely independent of the cash inflows from other assets or groups of assets.Financial instrumentsA financial asset or a financial liability is recognised only when the company becomes a party to the contractual provisions of the instrument.Basic financial instruments are initially recognised at the transaction price, unless the arrangement constitutes a financing transaction, where it is recognised at the present value of the future payments discounted at a market rate of interest for a similar debt instrument.Debt instruments are subsequently measured at amortised cost.Where investments in non-convertible preference shares and non-puttable ordinary shares or preference shares are publicly traded or their fair value can otherwise be measured reliably, the investment is subsequently measured at fair value with changes in fair value recognised in profit or loss. All other such investments are subsequently measured at cost less impairment.Other financial instruments, including derivatives, are initially recognised at fair value, unless payment for an asset is deferred beyond normal business terms or financed at a rate of interest that is not a market rate, in which case the asset is measured at the present value of the future payments discounted at a market rate of interest for a similar debt instrument.Other financial instruments are subsequently measured at fair value, with any changes recognised in profit or loss, with the exception of hedging instruments in a designated hedging relationship.Financial assets that are measured at cost or amortised cost are reviewed for objective evidence of impairment at the end of each reporting date. If there is objective evidence of impairment, an impairment loss is recognised in profit or loss immediately.For all equity instruments regardless of significance, and other financial assets that are individually significant, these are assessed individually for impairment. Other financial assets or either assessed individually or grouped on the basis of similar credit risk characteristics.Any reversals of impairment are recognised in profit or loss immediately, to the extent that the reversal does not result in a carrying amount of the financial asset that exceeds what the carrying amount would have been had the impairment not previously been recognised.