v3.25.2
Intangible Assets - Summary of Goodwill Impairment Test and Estimated Value in Use after Adjusting The Carrying Values of Assets and Was More Than Carrying Value Of Goodwill (Detail) - USD ($)
$ in Millions
Mar. 31, 2025
Mar. 31, 2024
Wind Power Segment [Member] | Ostro Energy Group [member]    
Disclosure of information for cash-generating units [line items]    
Amount by which unit's recoverable amount exceeds its carrying amount $ 5,615 $ 2,050
Wind Power Segment [Member] | ReNew Vayu Urja (KCT) [member]    
Disclosure of information for cash-generating units [line items]    
Amount by which unit's recoverable amount exceeds its carrying amount 1,527 1,185
Wind Power Segment [Member] | Others [Member]    
Disclosure of information for cash-generating units [line items]    
Amount by which unit's recoverable amount exceeds its carrying amount 2,185 2,318
Solar Power Segment [Member] | Prathamesh Solarfarms [member]    
Disclosure of information for cash-generating units [line items]    
Amount by which unit's recoverable amount exceeds its carrying amount 970 685
Solar Power Segment [Member] | Others [Member]    
Disclosure of information for cash-generating units [line items]    
Amount by which unit's recoverable amount exceeds its carrying amount $ 1,035 $ 911