Sometimes a value in your report cannot be properly tagged by an XBRL concept as defined in the US GAAP taxonomy. To tag the value accurately, you need to create a custom (or extension) concept, unique to your company. This article describes the steps for creating an extension concept along with some of the technical considerations.
Attributes That Define a Concept
The attributes that define the extension concept apply to every fact tagged with the concept, independent of each fact’s value. Concepts are made up of the following components:
- Standard label: The basic name for the concept that is used to generate the concept ID. For example, Net Income (Loss).
- ID: The concept’s technical name. For example NetIncomeLoss.
- Data type: This is the type of concept. It can be a non-numeric concept such as abstracts, members, text blocks, etc, or a numeric concept such as monetary, shares, percent, etc.
- Balance type: For monetary concepts, you can specify a balance type of credit or debit. A concept can also represent two conclusions: one for a positive fact value, and another for a negative value. For example, Gain (Loss) on Investments. If that is the case, use the balance type associated with the positive value.
- Concept definition: Human-readable description that is shown in viewing applications such as the SEC Viewer.
- Period type: For numeric concepts, you can specify instant or duration.
Maintaining Outline Naming Consistency
When you create new concepts, you are guided through the steps in a wizard. During this process, depending on the type of extension you want to create, the wizard suggests additional related concepts to create at the same time. For example, when you add a new table concept, the wizard gives you the option to create a corresponding Line Item concept and Table Text Block tag. If you create an Axis extension, a new Domain concept is suggested as well.
The wizard suggests these additional extensions to help to maintain the naming consistency of the XBRL outline structure. When you choose to create the related extensions as well, the wizard performs a validation process before it can proceed to the next step. Upon completion of the wizard, additional Line Item or Domain extensions that you create are automatically applied to the outline.
Creating an Extension Concept
You create an extension by completing the steps in the Create XBRL Extension Concept wizard.
- In Wdesk, open the document that contains a value for which you need an extension concept, and turn on XBRL.
- Select the value, and then, in the XBRL Detail Tagging dialog box, select Search line item concepts.
- From the XBRL Concept Search dialog box, click Create New Concept.
- In the Create XBRL Extension Concept wizard, navigate to and select the data type of the new extension concept. This example uses a Member type concept.
- For the Label step, type the standard label for the concept. If Wdesk detects an error with the label or the label is already in use, the Standard Label box will show a red outline. When this appears, mouse over the text box to display the error message.
- Click Next, and complete the Definition step as instructed in the wizard
- On the Summary step, review the element name, ID, and definition.
- Click Create Concept.
The new concept and any related concepts you opted to create will now be available for tagging. the concept will automatically appear in the XBRL Concept Search window.