Intangible assets are accounted for under ASC 350. Those with a finite useful life, like customer relationships or patents, are amortized over that life and tested for impairment when events suggest their value has fallen. Those with an indefinite life, such as some trademarks and broadcast licenses, are not amortized and are tested for impairment at least annually. In XBRL filings the total excluding goodwill is tagged IntangibleAssetsNetExcludingGoodwill, and the two groups are tagged FiniteLivedIntangibleAssetsNet and IndefiniteLivedIntangibleAssetsExcludingGoodwill.
Regulation S-X Rule 5-02.15 requires each class of intangible asset larger than 5 percent of total assets to be stated separately, with the basis for determining its amount, and significant additions or deletions to be explained. Rule 5-02.16 requires accumulated amortization of intangibles to be disclosed separately. The intangibles footnote usually shows gross carrying amounts, accumulated amortization, and expected amortization for each of the next five years.
Because acquired intangibles are recorded at fair value while internally built ones are not, two similar businesses can report very different intangible balances depending on whether they grew by acquisition. Amortization of acquired intangibles is a non-cash charge, and many companies exclude it from adjusted earnings measures. Analysts often subtract intangibles, along with goodwill, to arrive at tangible book value, since these assets would typically fetch little in a liquidation.