v3.25.2
Property, Plant and Equipment - Summary of Property, Plant and Equipment (Detail) - JPY (¥)
¥ in Millions
 12 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Disclosure of detailed information about property, plant and equipment [line items]    
Balance at beginning ¥ 14,257,788  
Balance at ending 15,333,693 ¥ 14,257,788
Gross carrying amount [Member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Balance at beginning 32,359,692 29,309,093
Additions 5,746,060 4,692,547
Sales or disposal (3,851,888) (3,578,908)
Foreign currency translation adjustments (316,737) 1,969,916
Other (69,609) (32,956)
Balance at ending 33,867,518 32,359,692
Accumulated depreciation, amortisation and impairment [Member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Balance at beginning (18,101,905) (16,675,119)
Depreciation (2,105,601) (1,957,111)
Impairment losses 0 (19,069)
Sales or disposal 1,553,891 1,496,254
Foreign currency translation adjustments 155,090 (911,486)
Other (35,301) (35,373)
Balance at ending (18,533,826) (18,101,905)
Land [Member] | Gross carrying amount [Member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Balance at beginning 1,441,811 1,426,370
Additions 7,622 5,217
Sales or disposal (22,255) (14,729)
Reclassification from construction in progress 15,842 5,691
Foreign currency translation adjustments 41 27,296
Other (14,940) (8,033)
Balance at ending 1,428,122 1,441,811
Land [Member] | Accumulated depreciation, amortisation and impairment [Member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Balance at beginning (6,985) (7,313)
Sales or disposal 1,244 579
Foreign currency translation adjustments (94) (825)
Other (1,091) 574
Balance at ending (6,927) (6,985)
Buildings [Member] | Gross carrying amount [Member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Balance at beginning 5,884,749 5,464,811
Additions 74,469 136,241
Sales or disposal (60,228) (39,296)
Reclassification from construction in progress 292,601 138,013
Foreign currency translation adjustments (47,461) 153,948
Other 25,932 31,032
Balance at ending 6,170,063 5,884,749
Buildings [Member] | Accumulated depreciation, amortisation and impairment [Member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Balance at beginning (3,753,786) (3,529,186)
Depreciation (169,778) (139,999)
Impairment losses   (208)
Sales or disposal 52,062 34,067
Foreign currency translation adjustments 30,142 (84,432)
Other (25,678) (34,029)
Balance at ending (3,867,037) (3,753,786)
Machinery and equipment [Member] | Gross carrying amount [Member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Balance at beginning 16,469,032 14,796,619
Additions 295,719 581,930
Sales or disposal (561,258) (545,829)
Reclassification from construction in progress 572,844 776,356
Foreign currency translation adjustments (154,892) 919,653
Other (202) (59,696)
Balance at ending 16,621,243 16,469,032
Machinery and equipment [Member] | Accumulated depreciation, amortisation and impairment [Member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Balance at beginning (12,719,614) (11,529,666)
Depreciation (1,039,696) (974,181)
Impairment losses 0 (18,862)
Sales or disposal 516,767 498,703
Foreign currency translation adjustments 109,227 (666,255)
Other (24,281) (29,354)
Balance at ending (13,157,598) (12,719,614)
Vehicles and equipment on operating leases [Member] | Gross carrying amount [Member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Balance at beginning 7,523,911 6,774,427
Additions 3,866,922 2,893,569
Sales or disposal (3,185,673) (2,974,283)
Reclassification from construction in progress 187 236
Foreign currency translation adjustments (94,981) 812,366
Other (58,420) 17,596
Balance at ending 8,051,945 7,523,911
Vehicles and equipment on operating leases [Member] | Accumulated depreciation, amortisation and impairment [Member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Balance at beginning (1,619,009) (1,605,744)
Depreciation (896,127) (842,931)
Sales or disposal 983,818 962,901
Foreign currency translation adjustments 15,759 (162,784)
Other 16,972 29,549
Balance at ending (1,498,586) (1,619,009)
Construction in progress [Member] | Gross carrying amount [Member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Balance at beginning 1,040,188 846,866
Additions 1,501,327 1,075,590
Sales or disposal (22,473) (4,771)
Reclassification from construction in progress (881,473) (920,295)
Foreign currency translation adjustments (19,444) 56,654
Other (21,979) (13,856)
Balance at ending 1,596,145 1,040,188
Construction in progress [Member] | Accumulated depreciation, amortisation and impairment [Member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Balance at beginning (2,510) (3,210)
Impairment losses 0  
Sales or disposal   3
Foreign currency translation adjustments 55 2,810
Other (1,223) (2,112)
Balance at ending ¥ (3,678) ¥ (2,510)