XBRL-based structured digital financial reporting - Blog: Digital Financial Reporting (using XBRL)

This blog post builds on my prior blog post related to understanding and expressing logical systems. What this blog post does is add information about HOW you implement the model of a logical system using the XBRL technical syntax.

First off, note that there is another model, the business report logical model, that is used as a basis for representing a business report. Basically, there are four core models involved that work together. Just keep that in the back of your mind; you don't need to understand those details to understand how to use XBRL.

Below you see the outline of the logic that is used to represent a financial report (business report). To that outline I have hooked an XBRL implementation of the logic artifact: (all of these come from the FRF for SMEs Ontology)

Model: (XBRL taxonomy + XBRL instance) The model is both the XBRL taxonomy that describes the model pluse the facts in the XBRL instance. (I could be wrong here and only the XBRL taxonomy is the "model", I will figure that out.)
Structure: (XBRL presentation; XBRL calculation; XBRL definition) Linkbased are used to provide structures. The names of structures, the extended link roles, are used to identify structures. Here is human readable information about XBRL structures.
Statement: The things within structures are statements. For example, the locators and arcs within an XBRL presentations linkbase articulate statements. XBRL labels linkbases are statements.
- Assertion:
  - Axiom: (XBRL formula) An XBRL formula consistency rule such as "Equity = (EquityAttributableToParent + EquityAttributableToNoncontrollingInterest)" is an axiom.
  - Theorem: (XBRL formula) An XBRL formula impute rule such as "If NoncurrentAssets = 0 and Assets <> 0 and CurrentAssets <> 0 Then NoncurrentAssets = Assets - CurrentAssets" is a theorem.
  - Restriction: (XBRL formula) An XBRL formula rule such as "(SharesIssued < SharesAuthorized) or (SharesIssued = SharesAuthorized)" is a restriction.
- Term: (XBRL taxonomy schema) An XBRL taxonomy scheme contains statements that define terms.
  - Simple term: (XBRL taxonomy schems) An XBRL taxonomy schema that defines concepts is an example of a statement defining a simple term. (Note that this XBRL taxonomy schema defines both simple terms and functional terms).
  - Functional term: (XBRL taxonomy schems) An XBRL taxonomy schema that defines the name of a disclosure is an example of a functional term.
- Relation: XBRL linkbases, XBRL instances, XBRL taxonomy schemas, XBRL formulas all provide examples of providing statements that express relations.
  - Is-a relation: (XBRL definition) Class-subclass relations defined within an XBRL definitions linkbase is an example of a statement that defines an "is-a" type of relation. A "class-subclass" relations is a type of is-a relation. Note that I am using a proprietary arcrole "class-subClass" rather than the standard "general-special" relation defined by XBRL. (This example is for US GAAP, I will update this when the FRF for SMEs class relations are provided.)
  - Has-a relation: (XBRL definitions) XBRL definition relations that use the "full-hasPart" relations that defines a functional component is one example of making a "has-a" relation type of statement. Another example of defining a functional component relates to disclosure mechanics rules defined in an XBRL definition linkbase. This is a mixture of "has-a" and "is-a" and "property-of" relations.
  - Property-of relation: (XBRL definitions) XBRL definition relations that articulates a property and then indicates what concepts have that property is an example of making a statement which defines a property. (This example is for US GAAP, I will update this when the FRF for SMEs properties are provided.)
  - Equivalence: (XBRL definition) XBRL definition relations used to map fundamental accounting concepts to XBRL taxonomy concepts used to represent those fundamental accounting concepts within a report is an example of making an equivalence statement. (Note that in this case I am using the proprietary "class-equivalentClass" arcrole rather than the XBRL provided "essence-alias" arcrole.)
  - Other predicates: (XBRL taxonomy schema defining general arcroles; XBRL taxonomy schema defining business rules arcroles) XBRL arcroles defined in an XBRL taxonomy schema are examples of how additional predicates can be defined using the XBRL technical syntax. The general arcroles and business rules arcroles are used in XBRL definition relations linkbases to make statements. Additionally, here is an example of defining a "wider-narrower" arcrole within the XBRL International Link Role Registry (LRR). Essentially, any predicate can be defined by XBRL International.
- Fact: (XBRL instance) An XBRL instance that is used to report facts is an example of statements used to express a fact.

What are the benefits of going through the trouble of expressing all of those semantics precisely and completely? See these two examples below. In particulary, check out the "Evidence Package" and the "Disclosure Mechanics". What you see is an example of what can be generated from the sort of semantics that you see above. These examples were created by XBRL Cloud. Pesseract also implements the logical system.

Microsoft 10-K: SEC Filing Page | XBRL instance | Evidence Package | Disclosure Mechanics
XASB Reference Implementation: XBRL instance | Evidence Package | Disclosure Mechanics

And so that is how you describe a logical system using the XBRL technical syntax! Are there better or different ways to achieve the desired results? Probably. But the primary point here is that you can express models, structures, and statements to provide a theory that describes a logical system or theory.