Acquired Finite-lived Intangible Asset, Weighted Average Useful Life (Deprecated 2012-01-31) ⓘCompanies tag every number in their SEC filings with a standard name. This page collects every value 3M CO reported under this one.us-gaap:AcquiredFiniteLivedIntangibleAssetWeightedAverageUsefulLife

The calculated weighted-average amortization period of a major class of finite-lived intangible assets acquired during the current period either individually or as part of a group of assets (in either an asset acquisition or business combination). A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company.