v3.26.1
Intangible Assets - Key Assumptions Used in Impairment Testing (Detail)
Mar. 31, 2026
Mar. 31, 2025
SMBC Consumer Finance Co., Ltd [member]    
Disclosure of impairment loss and reversal of impairment loss [line items]    
Pre-tax discount rate 12.34% 10.12%
Growth rate 1.00% 1.00%
Sumitomo Mitsui DS Asset Management Company, Limited [member]    
Disclosure of impairment loss and reversal of impairment loss [line items]    
Pre-tax discount rate 11.90% 12.30%
Growth rate 2.00% 2.00%
SMFG India Credit Company Limited [member]    
Disclosure of impairment loss and reversal of impairment loss [line items]    
Pre-tax discount rate 16.80% 16.90%
Growth rate 8.00% 8.00%
CCCMK Holdings Co., Ltd. [Member]    
Disclosure of impairment loss and reversal of impairment loss [line items]    
Pre-tax discount rate 11.23%
Growth rate 2.00%