Intangible property, like trademarks, copyrights, patents, or a right to receive money (e.g. accounts receivable) are all property, just like physical property (e.g. a house, a car, artwork) or cash (whether in a bank or under a mattress). Therefore, it is an asset of the estate, is something that could be reached by creditors, and if not used to pay creditors, is something will go to the estate's heir(s). Just like you can buy or sell a trademark, you can inherit it--or be forced to turn it over to or sell it for creditors (or to pay bills).