v3.26.1
Material Accounting Policies - Summary of Primary Subsidiaries (Details)
12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Alithya Canada Inc.    
Disclosure of subsidiaries [line items]    
Entity Alithya Canada Inc.  
Jurisdiction Quebec, Canada  
Percentage ownership (in percentage) 100.00% 100.00%
Alithya Consulting Inc.    
Disclosure of subsidiaries [line items]    
Entity Alithya Consulting Inc.  
Jurisdiction Quebec, Canada  
Percentage ownership (in percentage) 100.00% 100.00%
XRM Vision Inc. (a)    
Disclosure of subsidiaries [line items]    
Entity XRM Vision Inc. (a)  
Jurisdiction Quebec, Canada  
Percentage ownership (in percentage) 0.00% 100.00%
Alithya Digital Technology Corporation    
Disclosure of subsidiaries [line items]    
Entity Alithya Digital Technology Corporation  
Jurisdiction Ontario, Canada  
Percentage ownership (in percentage) 100.00% 100.00%
Alithya USA, Inc.    
Disclosure of subsidiaries [line items]    
Entity Alithya USA, Inc.  
Jurisdiction Delaware, USA  
Percentage ownership (in percentage) 100.00% 100.00%
Alithya Financial Solutions, Inc.    
Disclosure of subsidiaries [line items]    
Entity Alithya Financial Solutions, Inc.  
Jurisdiction Delaware, USA  
Percentage ownership (in percentage) 100.00% 100.00%
Alithya Zero2Ten, Inc. (a)    
Disclosure of subsidiaries [line items]    
Entity Alithya Zero2Ten, Inc. (a)  
Jurisdiction Delaware, USA  
Percentage ownership (in percentage) 0.00% 100.00%
Vitalyst, LLC (a)    
Disclosure of subsidiaries [line items]    
Entity Vitalyst, LLC (a)  
Jurisdiction Delaware, USA  
Percentage ownership (in percentage) 0.00% 100.00%
Datum Consulting Group, LLC (b)    
Disclosure of subsidiaries [line items]    
Entity Datum Consulting Group, LLC (b)  
Jurisdiction Indiana, USA  
Percentage ownership (in percentage) 0.00% 100.00%
Alithya France SAS    
Disclosure of subsidiaries [line items]    
Entity Alithya France SAS  
Jurisdiction France  
Percentage ownership (in percentage) 100.00% 100.00%
DCG Team UK Limited (b)    
Disclosure of subsidiaries [line items]    
Entity DCG Team UK Limited (b)  
Jurisdiction United Kingdom  
Percentage ownership (in percentage) 0.00% 100.00%
Alithya Numérique Maroc SARLAU    
Disclosure of subsidiaries [line items]    
Entity Alithya Numérique Maroc SARLAU  
Jurisdiction Morocco  
Percentage ownership (in percentage) 100.00% 100.00%
XRM Vision Maroc SARLAU    
Disclosure of subsidiaries [line items]    
Entity XRM Vision Maroc SARLAU  
Jurisdiction Morocco  
Percentage ownership (in percentage) 100.00% 100.00%
Datum Cybertech India Pvt Ltd. (b)    
Disclosure of subsidiaries [line items]    
Entity Datum Cybertech India Pvt Ltd. (b)  
Jurisdiction India  
Percentage ownership (in percentage) 0.00% 100.00%
eVerge Software and Technology Services Pvt Ltd.    
Disclosure of subsidiaries [line items]    
Entity eVerge Software and Technology Services Pvt Ltd.  
Jurisdiction India  
Percentage ownership (in percentage) 100.00% 0.00%
Alithya Enterpise Solutions, LLC    
Disclosure of subsidiaries [line items]    
Entity Alithya Enterprise Solutions, LLC (formerly Alithya Ranzal LLC)  
Jurisdiction Delaware, USA  
Percentage ownership (in percentage) 100.00% 100.00%
Alithya USA Consulting Services, LLC    
Disclosure of subsidiaries [line items]    
Entity Alithya USA Consulting Services, LLC (formerly Alithya Fullscope Solutions, Inc.)  
Jurisdiction Delaware, USA  
Percentage ownership (in percentage) 100.00% 100.00%
eVerge Intersts, Inc.    
Disclosure of subsidiaries [line items]    
Entity eVerge Interests, Inc. (note 4) (a)  
Jurisdiction Delaware, USA  
Percentage ownership (in percentage) 0.00% 0.00%