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Last Updated: January 2026
Source: https://specifications.xbrl.org
This document catalogs all current XBRL specifications, organized by functional area.
- Recommendation (REC): Approved, stable specification
- Candidate Recommendation (CR): Specification ready for implementation and testing
- Public Working Draft (PWD): Work in progress, open for public review
- Requirements (REQ): Requirements document
- Conformance Suite: Test cases for implementations
- Withdrawn: No longer recommended for use
Status: Recommendation (REC)
First Released: December 2003
Latest Update: July 2025 (Conformance Suite)
Stability: Pledge in place - committed to backward compatibility
The fundamental specification defining XBRL instances, taxonomies, concepts, linkbases, and basic validation rules.
Key Components:
- Instance documents structure
- Taxonomy schemas
- Five standard linkbase types (XBRL 2.1):
- Label linkbase (human-readable labels)
- Reference linkbase (authoritative references)
- Calculation linkbase (summation relationships)
- Presentation linkbase (display hierarchy)
- Definition linkbase (semantic relationships)
- Context and unit definitions
- Tuples and items
- Arc roles and link roles
Note: XBRL 2.1 defines the foundation for linkbases. Additional advanced linkbase specifications extend this foundation:
- Formula Linkbase (see Section 4) - Business rules and validation
- Table Linkbase (see Section 3) - Complex tabular layouts
- Generic Links - Custom relationship types
Conformance Levels:
- Minimally conforming: Syntax validation
- Fully conforming: Syntax + semantic validation
Status: Recommendation (REC)
Released: September 2006
Latest Update: September 2025 (Conformance Suite)
Extends XBRL 2.1 to support multi-dimensional reporting.
Key Features:
- Explicit dimensions with enumerated members
- Typed dimensions with typed values
- Hypercubes defining dimensional validity
- Primary items and dimension relationships
- Dimension-member hierarchies
- Dimension defaults
Core Concepts:
- Dimension: An aspect for categorizing facts
- Domain: Set of valid dimension values
- Hypercube: Defines which dimensions apply to concepts
- Axis: Dimension within a hypercube
Status: Recommendation (REC)
Released: April 2010
Latest Update: Ongoing maintenance
Embeds XBRL data within HTML/XHTML documents for dual human and machine consumption.
Specifications:
- Part 1: Core specification
- Part 2: Transformation rules
- Part 3: Additional features
Key Features:
- IX namespace elements embedded in HTML
- Transformation registry for format conversion
- Hidden facts for non-displayed data
- Continuation for split content
- Tuple support
- Footnote references
Common Elements:
ix:nonNumeric - Text/date factsix:nonFraction - Numeric factsix:fraction - Fractional valuesix:tuple - Tuple containersix:continuation - Split contentix:hidden - Non-displayed facts
Status: Implicit in XBRL 2.1
Note: Traditional XML format, now explicitly named under OIM
The original XML-based format for XBRL instances.
Status: Recommendation (REC)
Released: October 2021
Part of: Open Information Model
JSON representation of XBRL reports optimized for web applications and APIs.
Key Features:
- Simple, intuitive structure
- Easy consumption in programming languages
- Lightweight format
- Direct mapping to OIM
Structure:
{
"documentInfo": {...},
"facts": {
"fact-id": {
"value": "...",
"dimensions": {...}
}
}
}
Status: Recommendation (REC)
Released: October 2021
Latest Update: October 2025 (Table Constraints CR)
Part of: Open Information Model
CSV-based format optimized for large datasets and bulk reporting.
Key Features:
- JSON metadata file controls structure
- Multiple table support
- Efficient representation of repeating data
- Parameter references for common values
- Flexible column arrangements
- Property groups for shared dimensions
Components:
- Primary JSON metadata file
- One or more CSV data files
- Optional extended metadata files
Status: Recommendation (REC)
Version: 1.0 (March 2014)
Version 1.1: Public Working Draft (2017)
Latest: 1.0 remains current standard
Complexity: ⭐⭐⭐⭐⭐ (Most complex XBRL specification)
Defines tabular layouts for XBRL data presentation and collection. Used extensively in regulatory reporting (COREP, FINREP, Dutch SBR-DNB).
Key Features:
- Definition model (abstract table structure)
- Layout model (rendering instructions)
- Structural nodes (breakdowns of fact space)
- Axes definitions (X, Y, Z axes for multi-dimensional tables)
- Filters and constraints (aspect rules)
- Table parameters for variations
- Aspect models (coordinate resolution)
- Breakdown trees (open and closed)
- Rollup calculations across axes
Use Cases:
- Banking/Insurance Regulatory Reporting:
- COREP tables (Capital requirements - Basel III)
- FINREP tables (Financial reporting)
- Solvency II tables (Insurance)
- Dutch SBR-DNB reporting (100+ complex tables)
- Data entry templates
- Standardized presentations
- Complex multi-dimensional reports (3+ dimensions)
Implementation Complexity:
- One of the most challenging XBRL specifications to implement
- Typical implementation time: 12-16 months (full support)
- Requires:
- Breakdown tree evaluation
- Multi-dimensional coordinate resolution
- Aspect rule processing
- Complex filtering logic
- Rollup calculation engines
Real-World Usage:
- Required for financial institution reporting (banks, insurers, pension funds)
- Optional for most other XBRL taxonomies
- Heavily used in European banking supervision (EBA taxonomies)
- Critical for Dutch SBR-DNB (De Nederlandsche Bank)
Example Tables:
COREP C 01.00 - Own Funds Requirements
├─ 50+ rows (capital components)
├─ 20+ columns (regulatory adjustments)
├─ 3-4 dimensional axes
├─ Multiple breakdown trees
└─ Complex rollup calculations
FINREP F 01.01 - Balance Sheet
├─ 100+ rows (asset/liability categories)
├─ Multiple columns (periods, entities)
├─ Open/closed breakdowns
└─ Multi-dimensional filtering
Related Specifications:
- Depends on: XBRL 2.1, Dimensions 1.0, Formula 1.0 (for aspect rules)
- Works with: Generic Links, Generic Labels
Note: If not implementing banking/insurance regulatory reporting, Table Linkbase can often be skipped. For regular financial reporting (annual reports, tax returns), Dimensions 1.0 is usually sufficient.
Status: Recommendation (REC)
Released: March 2009
Provides flexible mechanism for creating custom linkbase relationships.
Key Features:
- Generic link elements
- Generic arc elements
- Custom relationship types
- Extended link role definitions
Status: Recommendation (REC)
Allows specification of preferred labels for concepts in different contexts.
Key Features:
- Label role customization
- Context-specific labeling
- Relationship-specific labels
Status: Recommendation (REC)
Released: October 2011 (formula-1.0)
Complexity: ⭐⭐⭐⭐ (Complex - requires XPath 2.0 knowledge)
Comprehensive framework for expressing business rules, validation assertions, and derived fact calculations.
Sub-Specifications (9 modules):
- Formula Core (formula) - Base specification, formula linkbase structure
- Variables (variable) - Fact selection and binding mechanisms
- Formula Filters (filter) - Fact filtering capabilities
- Value Assertions (va) - Value testing and validation
- Existence Assertions (ea) - Fact existence testing
- Consistency Assertions (ca) - Multi-fact consistency checks
- Generic Messages (msg) - Validation error messages
- Assertion Severity (sevr) - Error/warning classification
- Custom Functions (cfi) - Function registry and custom functions
Key Concepts:
- Variables: Select fact sets for processing
- Fact variables (select facts from instance)
- General variables (compute intermediate values)
- Parameter variables (accept input values)
- Filters: Refine fact selections
- Concept filters (by concept name)
- Period filters (by reporting period)
- Entity filters (by entity identifier)
- Unit filters (by measurement unit)
- Dimensional filters (by dimension values)
- Boolean filters (combine multiple filters)
- Assertions: Test and validate facts
- Value assertions: Test fact values against conditions
- Existence assertions: Check for required facts
- Consistency assertions: Verify relationships between facts
- Formulas: Derive new facts
- Calculate values from other facts
- Create new fact instances
- Support for XPath 2.0 expressions
XPath 2.0 Dependency:
- All formula expressions use XPath 2.0
- Requires XPath 2.0 processor (e.g., Saxon)
- Complex expressions possible
- Access to XBRL context, units, dimensions
Use Cases:
- Tax Reporting Validation:
Assert: TaxableIncome = GrossIncome - Deductions
Assert: TotalTax > 0 if TaxableIncome > Threshold
- Financial Statement Validation:
Assert: TotalAssets = TotalLiabilities + TotalEquity
Assert: CurrentRatio = CurrentAssets / CurrentLiabilities
- Dimensional Consistency:
Assert: Sum across all segments = Total reported
- Cross-Period Validation:
Assert: Prior period values unchanged in current filing
- Regulatory Compliance:
Assert: Capital adequacy ratio > minimum requirement
Assert: All required disclosures present
Real-World Usage:
- Dutch SBR: 200-500+ formula assertions per taxonomy
- SBR-RJ (Annual reports): 500+ assertions
- SBR-VPB (Corporate tax): 300+ assertions
- SBR-BTW (VAT): 200+ assertions
- European Banking: EBA COREP/FINREP validation rules
- SEC EDGAR: US Securities filing validations
- HMRC iXBRL: UK tax return validations
Implementation Requirements:
- XPath 2.0 processor (Saxon recommended)
- Variable binding engine
- Fact filtering system
- Assertion evaluation engine
- Message generation system
- Error reporting capabilities
Performance Considerations:
- Formula evaluation can be slow (complex XPath expressions)
- Optimization strategies:
- Fact pre-filtering
- XPath expression caching
- Parallel formula evaluation
- Incremental validation
- Expected performance: 1-5 seconds for 500 formulas
Related Specifications:
- Depends on: XBRL 2.1, Dimensions 1.0 (for dimensional filtering)
- Uses: XPath 2.0, XQuery, XML Schema data types
- Works with: Generic Links, Generic Messages
Example Formula Linkbase:
<formula:formula xlink:type="resource"
xlink:label="EquityCalculation"
value="$assets - $liabilities"
source="$equity">
<formula:aspects>
<formula:concept>
<formula:qname>us-gaap:StockholdersEquity</formula:qname>
</formula:concept>
</formula:aspects>
</formula:formula>
<formula:factVariable xlink:type="resource"
xlink:label="assets"
bindAsSequence="false">
<formula:factVariable>
<cf:concept>
<cf:qname>us-gaap:Assets</cf:qname>
</cf:concept>
</formula:factVariable>
</formula:factVariable>
Common Challenges:
- XPath 2.0 Learning Curve: Complex expression syntax
- Performance: Slow evaluation with many formulas
- Debugging: Hard to troubleshoot formula errors
- Testing: Comprehensive test coverage needed
- Maintenance: Formula updates require careful testing
Best Practices:
- Start with simple assertions
- Test formulas incrementally
- Use descriptive labels and messages
- Cache frequently-used variables
- Document complex expressions
- Profile and optimize slow formulas
Status: Recommendation (REC)
Released: 2018
Latest Update: 2025 (Calculation 1.1 enhancements)
Enhanced calculation validation beyond XBRL 2.1.
Features:
- Improved handling of numeric precision
- Better handling of missing facts
- Enhanced validation messages
- Calculation consistency checks
Status: Recommendation (REC)
Released: December 2015
Standard format for distributing XBRL taxonomies.
Key Features:
- ZIP-based container format
- Metadata file (META-INF/taxonomyPackage.xml)
- Taxonomy version identification
- Entry points definition
- Publisher information
- Superseded taxonomy tracking
Structure:
taxonomy-package.zip
├── META-INF/
│ └── taxonomyPackage.xml
└── taxonomy/
├── schemas/
└── linkbases/
Status: Recommendation (REC)
Released: December 2025
Latest Update: Requirements 1.1 (December 2025)
Standard format for distributing XBRL reports.
Key Features:
- Container for multiple reports
- Report metadata
- Taxonomy references
- Supporting documents
- Report relationships
Status: Recommendation (REC)
Version: 2.0 (February 2020)
Standardized approach for enumerations and code lists.
Key Features:
- Taxonomy-defined enumerations
- Domain member restrictions
- Enumeration linkbase
- Headusable vs. abstract members
- Multiple inheritance support
Benefits:
- Consistent code lists
- Easier taxonomy extensions
- Reduced taxonomy size
- Improved interoperability
Status: Recommendation (REC)
Released: February 2013
Documents changes between taxonomy versions.
Key Features:
- Versioning report format
- Change tracking
- Impact analysis
- Concept-related changes
- Relationship changes
- Namespace changes
Change Types:
- Concept additions/deletions
- Concept modifications
- Relationship changes
- Namespace changes
- Custom extensions
Status: Recommendation (REC)
Central repositories for shared resources.
Current Registries:
-
Unit Types Registry
- Standard unit definitions
- Currency codes (ISO 4217)
- Custom units
-
Functions Registry
- Custom XPath functions for formulas
- Mathematical functions
- String functions
- Date functions
-
Transformation Rules Registry
- Format conversions for iXBRL
- Date format transformations
- Number format transformations
- Boolean transformations
-
Link Role Registry
- Standard link roles
- Custom link role definitions
-
Arc Role Registry
- Standard arc roles
- Custom arc role definitions
Status: Recommendation (REC)
Framework for transaction-level reporting and general ledger data exchange.
Key Features:
- Account hierarchy
- Transaction details
- Journal entries
- Drill-down capabilities
- Multi-level aggregation
Status: Recommendation (REC)
Released: October 2021
Latest Update: December 2025 (Taxonomy Requirements)
Syntax-independent core model for XBRL, simplifying and modernizing the standard.
Key Documents:
- Core Model - Abstract information model
- xBRL-XML Mapping - XML format mapping
- xBRL-JSON Specification - JSON format
- xBRL-CSV Specification - CSV format
- OIM Common - Shared definitions
Simplifications from XBRL 2.1:
- No segment/scenario distinction
- Unified aspect model
- Simpler typed dimensions
- No fraction type
- No "forever" period
- Simplified footnotes
- Consistent date handling
Aspects in OIM:
- Concept
- Entity
- Period (start/end/instant)
- Unit
- Language
- Dimensions (taxonomy-defined)
Design Principles:
- Syntax independence
- Ease of consumption
- Developer-friendly
- Efficient representation
- Lossless transformation between formats
Status: Under Development
Purpose: Authentication and integrity verification
Planned Features:
- Report signing
- Partial signing
- Timestamp support
- Multiple signatures
- Certificate management
Some countries deman XAdES digital signatures (XML digital signatures). This works only with XML based XBRL instances.
Status: Under Development
Purpose: Efficient processing of very large datasets
Planned Features:
- Streaming instance processing
- Memory-efficient validation
- Progressive rendering
- Large file support
¶ Working Group and Work Product Development Process
Documents the specification development process within XBRL International.
Stages:
- Requirements gathering
- Public Working Draft
- Candidate Recommendation
- Recommendation
- Maintenance
Status: Withdrawn
Reason: Superseded by jurisdiction-specific guidance
- OIM Taxonomy Requirements (December 17, 2025)
- Report Packages 1.1 Requirements (December 4, 2025)
- xBRL-CSV Table Constraints (October 7, 2025 - CR)
- XBRL Dimensions Conformance Suite (September 9, 2025)
- XBRL 2.1 Conformance Suite (July 16, 2025)
For detailed technical guidance on implementing these specifications:
- Developer Resources: https://specifications.xbrl.org
- Best Practice Guides: Available for members
- Conformance Suites: Test cases for validation
- Reference Implementations: Open-source tools (e.g., Arelle)
See 03-XBRL-Dependency-Map for detailed dependency relationships between specifications.
If you're updating a Java XBRL processor from 2014-2018:
Major additions since 2018:
- Open Information Model (2021)
- xBRL-JSON (2021)
- xBRL-CSV (2021)
- Extensible Enumerations 2.0 (2020)
- Report Packages (2025)
- Table Constraints (2025)
Consider prioritizing:
- OIM support for modern format interoperability
- xBRL-JSON for web applications
- xBRL-CSV for bulk data
- Updated conformance suites
See 07-XBRL-Changes-Since-2018` for detailed migration guide.