January 2019 XBRL US State and Local Disclosure Modernization Working Group Using the CAFR Demonstration Taxonomy: A Preparer’s Guide Taxonomy Version: V0.5 RC01 Document Revision: 2019-01-17a This Guide has been prepared by the XBRL US State and Local Government Disclosure Modernization Working Group. The Guide is designed to help preparers understand the content and application of the Comprehensive Annual Financial Report (CAFR) Demonstration Taxonomy. As of the date of this publication, the Government Accounting Standards Board (GASB) has not yet reviewed contents of this document and the Demonstration Taxonomy to confirm/clarify proper use of definitions and references sourced from GASB’s Government Accounting Research System. It has not been approved by the Government Accounting Standards Working Group (GASB). All rights reserved. Reproduction and use rights are strictly limited. Copyright 2019 XBRL US Page 1 Table of Contents 1.0 Introduction 4 1.1 Intended Audience 4 1.2 Contents of the Guide 4 1.3 Spirit of the Project 5 2.0 Preparing a Filing 7 2.1 The Artifact You Will Prepare 7 2.2 Flow Chart for Tagging Values 8 2.3 Scope of the CAFR Demonstration Taxonomy 9 2.4 CAFR Preparer’s Advice 11 1000 - CAFR Cover 11 1100 - Letter of Transmittal 12 1200 - CAFR Audit Letter 13 2100 - CAFR Statement of Net Position, Assets and Deferred Outflows 14 2200 - CAFR Statement of Net Position, liabilities and deferred inflows 18 2300 - CAFR Statement of Net Position, net position 18 2500 - CAFR Statement of Activities, general revenues and 2600 - CAFR Statement of Activities, program revenues and expenses 20 3100 - CAFR Balance Sheet and 3200 - CAFR Statement of Revenues, Expenditures, and Changes in fund balance 21 2.5 Other Preparation Advice 23 2.5.1 Identifying the source and description of a CAFR Taxonomy element 23 2.5.2 Accessing tagged information 23 2.5.3 Examples illustrating the use of the CAFR Taxonomy 23 2.5.4 CAFR sections included in this demonstration taxonomy 23 2.5.6 When the available members do not fit your reporting 24 2.5.7 Other Element Attributes 24 Period Attributes 24 Balance Attributes 24 Negated labels—presentation 25 3.0 Future Considerations 26 3.1 Taxonomy Architecture 26 3.2 Data Quality Validation 26 3.3 Process for Inclusion of Elements 26 3.4 Entity Identifiers 27 3.5 Specifying the State 28 3.6 Magnitude 28 3.7 Long Term Maintenance 29 3.8 Use of Dimensions 29 Copyright 2019 XBRL US Page 2 Copyright 2019 XBRL US Page 3 1.0 Introduction 1.1 Intended Audience The intended audience of this Guide are those persons interested in understanding the intentions and scope of the CAFR Demonstration Taxonomy, and the subset of those persons wishing to use the Demonstration Taxonomy as the basis of preparing an XBRL or Inline XBRL (iXBRL1) representation of a Comprehensive Annual Financial Report (CAFR). Authors of the Guide assume that readers have sufficient knowledge of the financial reporting standards and reporting requirements for a CAFR. We also assume that those readers who intend to prepare an XBRL or iXBRL version of a CAFR filing have sufficient knowledge of XBRL and iXBRL to interpret the technical details in this Guide and suitable software for production of the iXBRL document. We leave it to the many other papers, presentations, videos, and books already published on this topic to provide a preparer’s technical education (see material from XBRL.US, XBRL.org) and more background on the effort and value proposition of disclosure modernization in general (see material from Data Coalition at datacoalition.org and the Data Foundation at the datafoundation.org). The worldwide use of XBRL and iXBRL data-encoding languages created a market for the production of financial reports in these formats. Those wishing to try their hand at preparing a filing are encouraged to consider their software options. Some of the software available significantly reduces the amount of technical knowledge needed to prepare a CAFR filing. A list of XBRL-enabled tools and services can be found on the XBRL US web site (https://xbrl.us/home/learn/tools-and-services/). 1.2 Contents of the Guide This Guide is broken into three broad sections: Introduction, Preparing a Filing, and Future Considerations. The Introduction shares the Working Group’s expectations for the Demonstration Taxonomy, intending to help preparers set realistic expectations for it, too. The second section, Preparing a Filing, uses examples to advise preparers on effective use of the Demonstration Taxonomy. The third section, Future Considerations, collects some of our thinking on what we might change if we revise the Demonstration Taxonomy. This Guide does not describe the software that may be used to create a filing, disclosure requirements or guidelines regarding these requirements, processes for producing a filing, or authoritative definitions for the elements in the Demonstration Taxonomy (though the 1 iXBRL® 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. Copyright 2019 XBRL US Page 4 Demonstration Taxonomy may include references to authoritative sources for some of its elements). You should refer to appropriate authoritative sources for this information. 1.3 Spirit of the Project All communication is translation. The goal of effective communication is to minimize ambiguity, include all necessary information, and not introduce any false information along the way. In everyday language, linguistic standards such as a grammar and a common vocabulary help us to communicate with one another. In communicating financial information, we rely on accounting standards and prevalent best practices to represent our common understanding for what we can say and how we can say it. “Disclosure modernization,” or the translation of financial information into a standard data encoding language based on a standard taxonomy, greatly increases the likelihood that we are communicating financial information in a clear, effective way. The movement to disclosure modernization for financial reporting is implemented through data encoding languages. Data encoding languages provide a machine-readable expression of the information we are trying to communicate. This machine-readable expression is often referred to as an open data report (which is a syntax-neutral expression of the idea). The data-encoding language called XBRL (for eXtensible Business Reporting Language) is the dominant machine-readable syntax for open data reports. It is a nonproprietary data encoding language first put into use in 2001 that provides a syntax for expressing financial reporting ideas. XBRL is used in concert with an XBRL taxonomy, which is a dictionary of terms that defines specific financial reporting ideas, and certain types of relationships between the terms (e.g. how numbers foot). In order to promote practical understanding of how disclosure modernization can work for a CAFR, the Working Group created this Demonstration Taxonomy and sample filings based on it. The purpose of this Demonstration Taxonomy is to provide a way for people to learn about the production and consumption of CAFR data encoded in XBRL. As sample filings become available, we will subsequently be able to demonstrate data extraction and data aggregation from these filings. In some sense our focus is on operational proof—that is, to show that methods for filing a CAFR in XBRL exist and that they work well. The Demonstration Taxonomy is sufficient for these purposes. It does not yet, however, declare a data architecture for a production-quality taxonomy. With this limitation in mind, we recommend that preparers focus on the function of a taxonomy encoded in XBRL rather than the specific form that this demonstration taxonomy has taken. The purpose of this document is to demonstrate that an operational CAFR can be created and to provide readers with ideas for how a full production-quality taxonomy might be designed and implemented in the future. Copyright 2019 XBRL US Page 5 The section on “Future Considerations” (below) details many recommendations and considerations for a production-quality taxonomy. Technically inclined readers with an interest in implementation details are directed to that section. Copyright 2019 XBRL US Page 6 2.0 Preparing a Filing 2.1 Preparing an XBRL filing A preparer’s technical goal is to produce a single artifact: an Inline XBRL (iXBRL) document. In brief, an iXBRL document is a special type of HTML document that has embedded within it data encoded in XBRL. An iXBRL document provides a preparer with both the visual benefits of an HTML document and the data benefits of an XBRL data document. A fact is a value encoded in XBRL, capturing the context that gives meaning to the value. Let’s take the number represented in the text “27,500,000”. That text is just a value. The text “27,600,000” encoded in XBRL would have specific context: the unit of measure e.g., reported as US dollars, precision e.g., rounded to the nearest hundred-thousand, tagged with a defined element e.g., as Net OPEB Asset, on an accrual basis. An XBRL fact offers much more control of your financial story than does plain text. Your filing will contain a lot of content, and a subset of that content will also be reported as facts encoded in XBRL. A preparer will need software that combines the production of the visual document with the production of the XBRL data document. The worldwide use of iXBRL led to the creation of numerous software programs capable of generating documents in this format. The XBRL portion of a filing is a subset of all the data contained therein. A preparer can only tag content if there are elements in the taxonomy that are appropriate to that content.