v3.26.1
Equity - Each Component of Other Comprehensive Income and Related Tax Effect Including Non-controlling Interests (Detail) - JPY (¥)
¥ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Items that will not be reclassified to profit or loss, Before-tax:      
Remeasurements of defined benefit plans, Net changes, Before-tax ¥ (10,970) ¥ 33,986 ¥ (30,696)
Net changes in revaluation of financial assets measured at fair value through other comprehensive income, Net changes, Before-tax 179,774 (23,320) (27,034)
Share of other comprehensive income of investments accounted for using the equity method, Net changes, Before-tax 3,398 (7,029) 8,976
Items that may be reclassified subsequently to profit or loss, Before-tax:      
Net changes in revaluation of financial assets measured at fair value through other comprehensive income, Amount incurred during the year, Before-tax (215) 582 149
Net changes in revaluation of financial assets measured at fair value through other comprehensive income, Reclassification to profit or loss, Before-tax 120 (50) (78)
Net changes in revaluation of financial assets measured at fair value through other comprehensive income, Net changes, Before-tax (95) 532 71
Exchange differences on translating foreign operations, Amount incurred during the year, Before-tax 702,846 (162,200) 880,235
Exchange differences on translating foreign operations, Reclassification to profit or loss, Before-tax (921) (125) (5,185)
Exchange differences on translating foreign operations, Net changes, Before-tax 701,925 (162,325) 875,050
Cash flow hedge, Amount incurred during the year, Before-tax 76,045    
Cash flow hedge, Reclassification to profit or loss, Before-tax (60,072)    
Cash flow hedge, Net changes, Before-tax 15,973    
Share of other comprehensive income of investments accounted for using the equity method, Amount incurred during the year, Before-tax 63,775 20,910 57,139
Share of other comprehensive income of investments accounted for using the equity method, Reclassification to profit or loss, Before-tax (3,999) (1,319) 64
Share of other comprehensive income of investments accounted for using the equity method, Net changes, Before-tax 59,776 19,591 57,203
Total other comprehensive income, Before-tax 949,781 (138,565) 883,570
Items that will not be reclassified to profit or loss, Tax benefit (expense):      
Remeasurements of defined benefit plans, Net changes, Tax benefit (expense) (4,076) (7,259) 11,765
Net changes in revaluation of financial assets measured at fair value through other comprehensive income, Net changes, Tax benefit (expense) (48,660) 9,843 1,565
Share of other comprehensive income of investments accounted for using the equity method, Net changes, Tax benefit (expense) 82 530 (676)
Items that may be reclassified subsequently to profit or loss, Tax benefit (expense):      
Net changes in revaluation of financial assets measured at fair value through other comprehensive income, Amount incurred during the year, Tax benefit (expense) 52 (128) (83)
Net changes in revaluation of financial assets measured at fair value through other comprehensive income, Reclassification to profit or loss, Tax benefit (expense) (28) 11 68
Net changes in revaluation of financial assets measured at fair value through other comprehensive income, Net changes, Tax benefit (expense) 24 (117) (15)
Exchange differences on translating foreign operations, Amount incurred during the year, Tax benefit (expense) (26) (2) (2,727)
Exchange differences on translating foreign operations, Reclassification to profit or loss, Tax benefit (expense) 26 2 2,727
Exchange differences on translating foreign operations, Net changes, Tax benefit (expense)
Cash flow hedge, Amount incurred during the year, Tax benefit (expense) (23,574)    
Cash flow hedge, Reclassification to profit or loss, Tax benefit (expense) 18,622    
Cash flow hedge, Net changes, Tax benefit (expense) (4,952)    
Share of other comprehensive income of investments accounted for using the equity method, Amount incurred during the year, Tax benefit (expense) 171 (1,190) (2,850)
Share of other comprehensive income of investments accounted for using the equity method, Reclassification to profit or loss, Tax benefit (expense)
Share of other comprehensive income of investments accounted for using the equity method, Net changes, Tax benefit (expense) 171 (1,190) (2,850)
Total other comprehensive income, Tax benefit (expense) (57,411) 1,807 9,789
Items that will not be reclassified to profit or loss, Net-of-tax:      
Remeasurements of defined benefit plans, Net changes, Net-of-tax (15,046) 26,727 (18,931)
Net changes in revaluation of financial assets measured at fair value through other comprehensive income, Net changes, Net-of-tax 131,114 (13,477) (25,469)
Share of other comprehensive income of investments accounted for using the equity method, Net changes, Net-of-tax 3,480 (6,499) 8,300
Items that may be reclassified subsequently to profit or loss, Net-of-tax:      
Net changes in revaluation of financial assets measured at fair value through other comprehensive income, Amount incurred during the year, Net-of-tax (163) 454 66
Net changes in revaluation of financial assets measured at fair value through other comprehensive income, Reclassification to profit or loss, Net-of-tax 92 (39) (10)
Net changes in revaluation of financial assets measured at fair value through other comprehensive income, Net changes, Net-of-tax (71) 415 56
Exchange differences on translating foreign operations, Amount incurred during the year, Net-of-tax 702,820 (162,202) 877,508
Exchange differences on translating foreign operations, Reclassification to profit or loss, Net-of-tax (895) (123) (2,458)
Exchange differences on translating foreign operations, Net changes, Net-of-tax 701,925 (162,325) 875,050
Cash flow hedge, Amount incurred during the year, Net-of-tax 52,471    
Cash flow hedge, Reclassification to profit or loss, Net-of-tax (41,450)    
Cash flow hedge, Net changes, Net-of-tax 11,021
Share of other comprehensive income of investments accounted for using the equity method, Amount incurred during the year, Net-of-tax 63,946 19,720 54,289
Share of other comprehensive income of investments accounted for using the equity method, Reclassification to profit or loss, Net-of-tax (3,999) (1,319) 64
Share of other comprehensive income of investments accounted for using the equity method, Net changes, Net-of-tax 59,947 18,401 54,353
Total other comprehensive income, net of tax ¥ 892,370 ¥ (136,758) ¥ 893,359