Explain the meaning of an impairment of an asset. Provide several examples. What accounting event should occur when an asset has become substantially impaired?

Several years ago Walker Security purchased for $120,000 a well-known trademark for padlocks and other security products. After using the trademark for three years, Walker Security discontinued it altogether when the company withdrew from the lock business and concentrated on the manufacture of aircraft parts. Amortization of the trademark at the rate of $3,000 a year is being continued on the basis of a 20-year life, which the owner says is consistent with accounting standards. Do you agree? Explain.