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Your Guide to the 2021 US GAAP Taxonomy Update

SEC Reporting
2021 US GAAP Taxonomy Update
6 min read
Sammi Azoulay
Team Manager of XBRL Data Quality & Training
Published: April 21, 2021
Last Updated: April 25, 2023

As of March 22, 2021, the EDGAR system was updated to support the 2021 US GAAP Taxonomy (2021 UGT), 2021 SEC Reporting Taxonomy (2021 SRT), and other SEC taxonomies releases. The 2021 taxonomies bring a variety of changes, including element updates and modeling changes.

The chart below illustrates the summary of changes in the UGT and SRT taxonomies.

  Number of Elements
  2021 US GAAP SRT
Reference changes 914 879 35
New elements 419 348 71
Taxonomy implementation notes 517 490 27
Definition changes 90 85 5
Label changes 361 359 2
Deprecated items 295 295 0
Other (mostly Data Type -  Extensible Enumerations, some period type changes) 289 288 1
Subtotal 2,885 2,744 141
Deleted elements 574    
Total 3,459    


The Financial Accounting Standards Board (FASB) taxonomy team continues to enhance the taxonomy to address required Accounting Standards Updates, common reporting practices, and designing projects focused on improving the utility of the taxonomy. For the 2021 UGT, while various elements and areas were impacted, key updates related to the below topics.

ASC Topic 326 - Financial Instruments - Credit Losses 

The 2021 UGT includes three key updates related to ASC 326 and credit loss reporting: policy election for reporting accrued interest, past due disclosures, and investments net of allowance for credit losses. New elements were introduced and there was remodeling from a line item approach to a dimensionally driven approach for age analysis of past due disclosures. 

  • Filer Action: Filers should evaluate new concepts that may be applicable to their reporting scenarios and make updates for remodeling of past due disclosures.

Taxonomy Topical Project - Asset Acquisitions

Since the adoption of ASU 2017-01 "Clarifying the Definition of a Business," there has been an increase in reporting of asset acquisitions. Before the 2021 UGT updates were made to the taxonomy, filers may have created extensions or utilized the Business Combination elements for asset acquisition disclosures. It is important to note that Business Combination elements are not expected to be utilized on these types of disclosures as they are out of scope of the business combination accounting standards. Through observation, feedback, and analysis, FASB updated section "800000 - Disclosure - Business Combination and Asset Acquisitions" of the taxonomy and expanded to include new common practice elements for asset acquisitions.  

  • Filer Action: Filers that disclose asset acquisitions should review current XBRL® modeling against the new standard elements provided in the taxonomy. Filers should update to new standard elements where available and ensure they are utilizing the new modeling approach.   

ASC Topic 852 - Reorganizations

In 2020, there was an observed increase in reporting of reorganizations. To provide consistency and to closely align to reporting practices, FASB included updates to existing modeling by moving from a line item driven approach to a dimensionally driven approach.

  • Filer Action: Filers previously utilizing the reorganization line item concepts that are now deprecated should replace them with face statement elements and utilize the "Reorganization, Chapter 11 [Axis]." New members were added to this existing axis to capture predecessor and type of adjustment information.   

Other Updates

Other updates include deprecations in accounting changes disclosures due to redundancy and new elements added for statistical disclosures for Banks and Savings and Loan Registrants. 

The FASB taxonomy team continues to make technical improvements to help filers with taxonomy implementation. The 2021 taxonomies provide improvements to existing features as well as the introduction of new guidance tools.

  • Taxonomy Implementation Notes (TINs): While TINs were originally introduced in the 2016 taxonomy, for the 2021 UGT FASB added new categorization (Resource, Transition, Usage, and Value) to provide more clarification to the purpose of a TIN and better differentiate between the types of guidance. 

  • Extensible Enumerations: FASB introduced the use of extensible lists in the 2017 taxonomy to associate additional information to facts. The update to extensible enumerations in 2021 is a technical update to help improve on limitations of extensible lists and improve data usability. Extensible enumeration formatting differs slightly from extensible lists, going from "us-gaap:XXXX" or "abc:XXXX" (company specific) to "" or "" (company specific), which may be automated by software such as Workiva. Filers should review fact value inputs for these differences.  

  • Guidance ItemType: Five new "Guidance Item Type" elements were added to the 2021 taxonomy. These elements provide additional information to a set of elements or disclosure areas with the purpose to provide guidance on taxonomy implementation. These elements are not expected be applied to any facts. The guidance provided by these new elements include extension guidance, modeling guidance, and links to helpful FASB taxonomy resources (i.e., Taxonomy Implementation Guides). These elements can be found by utilizing the Workiva Taxonomy Analyzer and filtering the "Data Type" for "guidanceItemType."

  • XBRL US DQC Rules Taxonomy (DQCRT): In 2020, the FASB taxonomy team introduced the XBRL US DQC Rules Taxonomy (DQCRT). This taxonomy includes XBRL US Data Quality Committee (DQC) rules to provide additional visibility to data quality validation rules for XBRL filings with the SEC. Three additional DQC rules were added to the 2021 DQCRT, bringing it to a total of six rules. Starting with the 2021 US GAAP Taxonomy, the SEC EDGAR system validates DQC rules that are included in the 2021 DQCRT.

This year's new taxonomy focused on key topical areas (Credit Losses, Asset Acquisitions, and Reorganization) and technical taxonomy improvements. We recommend filers not only focus on deprecated elements but review new elements, modified labels and definitions, and updated data types. 

To provide guidance to filers, the FASB offers a number of resources on their website:

For other learning opportunities, watch the Workiva calendar of events for upcoming webinars and workshops on filing best practices, XBRL tagging, and more.

Last, but not least, please keep in mind that the SEC strongly encourages you to use the most current version of the taxonomy for your filings. Even though the 2019 taxonomy is not expected to be removed before June, for those who are currently using the 2019 version, it would be prudent to have a plan in place well before the deadline. Your service providers can also help you on your path to a successful migration this year.

If you need assistance with migration, XBRL tagging, or learning more about how Workiva can help, please reach out.

XBRL® is a trademark of XBRL International, Inc. All rights reserved. The XBRL® standards are open and freely licensed by way of the XBRL International License Agreement.

About the Author
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Sammi Azoulay

Team Manager of XBRL Data Quality & Training

Sammi Azoulay is a Certified Public Accountant and Project Management Professional. She holds a bachelor’s and master’s degree in Accounting from Binghamton University's School of Management. She is a member of the Professional Services team at Workiva and focuses her attention on XBRL advisory and training and data quality initiatives. She has prior experience as an auditor and as senior accountant for a publicly traded company.

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