The US GAAP Taxonomy revision of 2017 introduced a new XBRL design feature called Extensible Lists to help companies filing their reports with the US SEC provide or tag additional qualitative information in their instance documents. There are 27 extensible list elements, and they are introduced in the taxonomy with the suffix ‘[Extensible List]’. The tagging of additional information is to be done using the base or extension taxonomy elements as facts or values. However, in the absence of detailed guidance on how these elements work, very few filers have been using them in their XBRL filings.
To help filers understand extensible list elements, the Financial Accounting Standards Board has released a Proposed Taxonomy Implementation Guide. Through this guide, FASB says it intends to explain the purpose of the extensible lists feature, “when it is intended to be used, and the modeling of disclosure requirements using this feature”. Furthermore, the GAAP and SEC Reporting Taxonomies are going to feature improvements to the extensible list elements in 2021 to improve their usability. Extensible Enumerations 2.0 (EE 2.0) has been in the works since early 2020 when the XBRL International Standards Board suggested an update. A few pointers on extensible lists follow.
Why are Extensible Lists needed?
We will try to understand that with an example.
A company wants to report total revenues of $5 mln, breaking up the figure into $3 mln from its minerals business and $2 mln from its oil and gas business. Its revenues from minerals come from the US, and revenues from oil and gas from Canada.
If the company does not use extensible list elements, it opts for one of two approaches to tag this information.
Approach 1: Using a single axis for tagging:
Under this approach, the company will attach members from only one axis for tagging of facts.
Approach 2: Using two axes for tagging:
Under this approach, the company will attach members from only one axis for tagging of facts. Here’s how the introduction of extensible list elements changes the tagging approach:
The disclosure that revenue from minerals comes from the US represents ‘non-disaggregating qualitative information’. Or to put it simply, for this company ‘minerals’ cannot be separated from ‘US’. The $3 mln in the table above represents one value with two characteristics, with the product type (minerals) chosen as the primary disaggregating characteristic and the geographic location (US) as the non-disaggregating characteristic.
Therefore, an axis element for geographic location is not used for the non-disaggregating information, but an extensible list element for geographic location is tagged with a member ‘US’, as a value for this extensible list element. FASB defines ‘disaggregation’ as a breakdown of a primary line item into its component parts by a characteristic using axis and member elements.
Extensible Lists have been introduced for the following reasons:
They simplify the use of axis elements in XBRL filings
Extensible lists focus on the use of axis elements for disaggregation only – which is what they were intended for. With the introduction of extensible list elements, axis elements (attaching the member element to the fact-value) need to be used only where disaggregating information is disclosed.
Here is an example of disaggregating information –
Sales disaggregated by the country in which the products have been sold would use “Revenues” and “Geographical [Axis]” with members representing the various countries in which the products are sold.
They facilitate the consumption of XBRL data
As of now, users/research analysts extracting XBRL data from files find it impossible to identify whether the value to which a member is assigned conveys disaggregating information or non-disaggregating information. An increase in the use of extensible list elements will help users/research analysts easily differentiate between the two, thereby facilitating the use of formulae and logic to derive values.
They provide a mechanism to convey non-disaggregating information disclosed in lieu of axis elements
The use of extensible lists is recommended in cases where non-disaggregating information is disclosed.
They reuse members for disaggregation and domain members for location
The members used with axis elements are also intended to be used with extensible list elements, which promotes consistency and comparability of the XBRL data. It also ensures that data is consistent and comparable regardless of how information is disclosed.
Facilitate structured data
The use of extensible list elements is primarily intended to limit the use of axis elements for tagging disaggregating information. This helps facilitate data consumption since data/tagging becomes more structured.
How and when to use Extensible Lists?
There are two types of facts that require the use of extensible list elements:
- Characteristic facts, and
- Location facts
Characteristic facts
Most extensible list elements in the taxonomy are for tagging information about certain characteristics for an accounting concept when those characteristics are not disaggregating the values.
Example 1: Total debt securities of $500 include corporate securities worth $300 and US government securities worth$200.
Tagging Approach:
In this case, since the disclosure of $500 (total debt securities)of the reporting entity is being disaggregated by $300 (corporate securities) and $200 (US government securities), the use of an extensible list element is not required.
Example 2: A company’s investment of $500 in debt securities represents corporate debt securities.
Tagging Approach:
The disclosure that debt securities are corporate securities represents non-disaggregating qualitative information. In place of an axis element being used to indicate these are Corporate Debt Securities, the extensible list ‘Debt Securities, Available-for-sale, Type [Extensible List]’ is to be used to tag the information. The value to report for the extensible list element is the member for corporate securities, as shown in the table above.
Location facts
Other extensible list elements in the taxonomy are used for tagging a line item in the footnotes or other parts of the financial statement when it is part of a specific accounting concept in one of these primary statements (financial position, income, or comprehensive income) but is not separately presented in the primary statement.
Let us look at two examples of such elements in the taxonomy:
a) The element for indicating the line item in the statement of financial position in which restricted cash is included
Example: Extract from notes to accounts– ‘Restricted cash of $500 is included in other current assets in the Balance Sheet.’
Tagging Approach:
The above tagging indicates the line item in the statement of financial position in which restricted cash is included (which is Other Current Assets).
b) The element for indicating the line item in the statement of income or comprehensive income in which operating lease income is included.
Example: Extract from notes to accounts– ‘Operating lease income of $1,000 is included in other non-operating income in the Income Statement’.
Tagging Approach:
The above tagging indicates the line item in the income statement in which operating lease income is included.
Where are Extensible Lists available for use?
Users can refer to the ‘Extensible Lists’ tab of the‘2020 US GAAP Taxonomy (Excel Version)’ released by FASB. It contains all 282 extensible list elements, along with a list of members allowed with a particular element.
Here are examples of how Characteristic fact and Location fact extensible list elements from the above list can be represented:
Type of fact: Characteristic fact
- Prefix:us-GAAP
- Element name:RevenueFromContractWithCustomerDurationExtensibleList
- Documentation: Indicates the duration of the contract with the customer. Includes, but is not limited to, short-term and long-term contracts.
- ExtensibleListDomain:ContractWithCustomerDurationDomain
- Domain-member relationship:ShortTermContractWithCustomerMember; LongTermContractWithCustomerMember
Type of fact: Location fact
- Prefix:us-GAAP
- Element name:RestrictedCashAssetStatementOfFinancialPositionExtensibleList
- Documentation: Indicates line item in the statement of financial position that includes cash restricted to withdrawal or usage.
- ExtensibleListDomain:AssetsAbstract
- Domain-member relationship:OtherAssets; PrepaidExpenseAndOtherAssets; CashAndCashEquivalentsAtCarryingValue; DerivativeAssets; Goodwill; DueFromRelatedParties; AccruedInvestmentIncomeReceivable; IncomeTaxReceivable
* ‘ExtensibleListDomain’ is an element under which values for an extensible list element are presented in the taxonomy
* ‘Domain-member relationship’ element represents a list of values/elements allowed to be used with the extensible list element
We hope you find this high-level summary of Extensible Lists helpful. Stay tuned in for our upcoming post where we will cover the steps for tagging disclosures with extensible list elements in greater detail.
