XML 156 R144.htm IDEA: XBRL DOCUMENT v3.8.0.1
Employee Benefits - Summary of Defined Benefit Plans (Detail) - INR (₨)
₨ in Millions
12 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Mar. 31, 2016
Mar. 31, 2018
Mar. 31, 2017
Disclosure of net defined benefit liability (asset) [line items]          
Defined benefit obligation at the beginning of the year ₨ (351)        
Present value of unfunded obligation       ₨ (147) ₨ (351)
Recognized asset/(liability) (351) ₨ (351)   (147) (351)
Re-measurement of net defined benefit liability/(asset)          
Return on plan assets excluding interest income (501) (692) ₨ (351)    
Defined benefit obligation at the end of the year (147) (351)      
Plan assets [member]          
Disclosure of net defined benefit liability (asset) [line items]          
Defined benefit obligation at the beginning of the year 7,919 6,488      
Acquisitions 28 561      
Recognized asset/(liability) 7,919 6,488 6,488 ₨ 8,507 ₨ 7,919
Expected return on plan assets 483 499      
Employer contributions 59 186      
Benefits paid   (4)      
Re-measurement of net defined benefit liability/(asset)          
Return on plan assets excluding interest income 18 189      
Defined benefit obligation at the end of the year ₨ 8,507 ₨ 7,919 ₨ 6,488