v3.26.1
Financial liabilities - Summary of Financial Liabilities (Detail) - JPY (¥)
¥ in Millions
12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Disclosure of reconciliation of liabilities arising from financing activities [line items]    
Beginning balance ¥ 38,792,879 ¥ 36,561,780
Cash flow 832,992 2,584,995
Acquisitions 549,798 164,348
Changes in foreign currency exchange rates 3,183,234 (535,545)
Other (153,435) 17,301
Ending balance 43,205,469 38,792,879
Current liabilities [Member]    
Disclosure of reconciliation of liabilities arising from financing activities [line items]    
Beginning balance 15,829,516 15,406,284
Cash flow (12,047,232) (10,796,586)
Reclassification 12,618,903 11,440,383
Changes in foreign currency exchange rates 1,309,209 (241,512)
Other (129,292) 20,947
Ending balance 17,581,104 15,829,516
Current liabilities [Member] | Short-term debt [Member]    
Disclosure of reconciliation of liabilities arising from financing activities [line items]    
Beginning balance 5,464,469 5,487,959
Cash flow (90,691) 75,675
Changes in foreign currency exchange rates 455,722 (99,165)
Other (130,417) 0
Ending balance 5,699,083 5,464,469
Current liabilities [Member] | Current portion of long-term debt [Member]    
Disclosure of reconciliation of liabilities arising from financing activities [line items]    
Beginning balance 10,272,900 9,844,870
Cash flow (11,601,270) (10,786,012)
Reclassification 12,179,370 11,336,112
Changes in foreign currency exchange rates 850,496 (141,748)
Other 17,089 19,679
Ending balance 11,718,586 10,272,900
Current liabilities [Member] | Current portion of long-term lease liabilities [Member]    
Disclosure of reconciliation of liabilities arising from financing activities [line items]    
Beginning balance 92,147 73,456
Cash flow (355,271) (86,249)
Reclassification 439,532 104,271
Changes in foreign currency exchange rates 2,991 (599)
Other (15,964) 1,268
Ending balance 163,435 92,147
Non current liabilities [Member]    
Disclosure of reconciliation of liabilities arising from financing activities [line items]    
Beginning balance 22,963,363 21,155,496
Cash flow 12,880,225 13,381,581
Acquisitions 549,798 164,348
Reclassification (12,618,903) (11,440,383)
Changes in foreign currency exchange rates 1,874,025 (294,033)
Other (24,143) (3,646)
Ending balance 25,624,365 22,963,363
Non current liabilities [Member] | Long-term debt [Member]    
Disclosure of reconciliation of liabilities arising from financing activities [line items]    
Beginning balance 22,522,158 20,766,384
Cash flow 12,880,225 13,381,581
Reclassification (12,179,370) (11,336,112)
Changes in foreign currency exchange rates 1,856,234 (290,753)
Other (2,460) 1,059
Ending balance 25,076,787 22,522,158
Non current liabilities [Member] | Long-term lease liabilities [Member]    
Disclosure of reconciliation of liabilities arising from financing activities [line items]    
Beginning balance 441,204 389,112
Acquisitions 549,798 164,348
Reclassification (439,532) (104,271)
Changes in foreign currency exchange rates 17,791 (3,280)
Other (21,683) (4,705)
Ending balance 547,578 441,204
Derivatives [Member]    
Disclosure of reconciliation of liabilities arising from financing activities [line items]    
Beginning balance 37,829 (40,578)
Cash flow (40,982) (5,189)
Changes in foreign currency exchange rates (1,917) (478)
Changes in fair value (24,507) 84,074
Ending balance ¥ (29,578) ¥ 37,829