v3.26.1
Goodwill and Intangible Assets - Summary of Estimated Remaining Amortization Period for Intangible Assets Acquired on Acquisition (Detail)
₨ in Millions
 12 Months Ended
Mar. 31, 2026
INR (₨)
yr
Disclosure of intangible assets material to entity [line items]  
Net carrying value | ₨ ₨ 29,176
Capco - customer-related intangible [member]  
Disclosure of intangible assets material to entity [line items]  
Estimated remaining amortization period 4.08
Net carrying value | ₨ ₨ 14,013
Capco - marketing-related intangible [member]  
Disclosure of intangible assets material to entity [line items]  
Estimated remaining amortization period 5.08
Net carrying value | ₨ ₨ 5,230
AVT [Member]  
Disclosure of intangible assets material to entity [line items]  
Net carrying value | ₨ ₨ 1,602
Harman Customer Related Intangible [member]  
Disclosure of intangible assets material to entity [line items]  
Estimated remaining amortization period 5.67
Net carrying value | ₨ ₨ 5,650
Harman Marketing Related Intangible [Member]  
Disclosure of intangible assets material to entity [line items]  
Estimated remaining amortization period 2.67
Net carrying value | ₨ ₨ 1,045
Vara Infotech Private Limited [member]  
Disclosure of intangible assets material to entity [line items]  
Net carrying value | ₨ 430
Aggne [Member]  
Disclosure of intangible assets material to entity [line items]  
Net carrying value | ₨ ₨ 392
Rational Interaction, Inc. [Member]  
Disclosure of intangible assets material to entity [line items]  
Estimated remaining amortization period 0.89
Net carrying value | ₨ ₨ 318
Eximius Design, LLC [Member]  
Disclosure of intangible assets material to entity [line items]  
Estimated remaining amortization period 1.4
Net carrying value | ₨ ₨ 371
Convergence Acceleration Solutions, LLC [Member]  
Disclosure of intangible assets material to entity [line items]  
Estimated remaining amortization period 2.03
Net carrying value | ₨ ₨ 125
Bottom of range [member] | AVT [Member]  
Disclosure of intangible assets material to entity [line items]  
Estimated remaining amortization period 0.21
Bottom of range [member] | Vara Infotech Private Limited [member]  
Disclosure of intangible assets material to entity [line items]  
Estimated remaining amortization period 0.5
Bottom of range [member] | Aggne [Member]  
Disclosure of intangible assets material to entity [line items]  
Estimated remaining amortization period 0.87
Top of range [member] | AVT [Member]  
Disclosure of intangible assets material to entity [line items]  
Estimated remaining amortization period 4.72
Top of range [member] | Vara Infotech Private Limited [member]  
Disclosure of intangible assets material to entity [line items]  
Estimated remaining amortization period 3.5
Top of range [member] | Aggne [Member]  
Disclosure of intangible assets material to entity [line items]  
Estimated remaining amortization period 1.87