v3.26.1
Property, Plant and Equipment - Summary of Property, Plant and Equipment (Detail) - JPY (¥)
¥ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Disclosure of detailed information about property, plant and equipment [line items]    
Balance at beginning ¥ 15,333,693  
Balance at ending 17,067,365 ¥ 15,333,693
Gross carrying amount [Member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Balance at beginning 33,867,518 32,359,692
Additions 5,758,408 5,746,060
Sales or disposal (3,352,824) (3,851,888)
Foreign currency translation adjustments 1,844,836 (316,737)
Transfer to assets held for sale (1,308,970)  
Other (237,603) (69,609)
Balance at ending 36,571,364 33,867,518
Accumulated depreciation, amortisation and impairment [Member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Balance at beginning (18,533,826) (18,101,905)
Depreciation (2,215,854) (2,105,601)
Impairment losses (8,825)  
Sales or disposal 1,345,122 1,553,891
Foreign currency translation adjustments (900,016) 155,090
Transfer to assets held for sale 826,852  
Other (17,453) (35,301)
Balance at ending (19,504,000) (18,533,826)
Land [Member] | Gross carrying amount [Member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Balance at beginning 1,428,122 1,441,811
Additions 5,806 7,622
Sales or disposal (2,901) (22,255)
Reclassification from construction in progress 57,729 15,842
Foreign currency translation adjustments 27,751 41
Transfer to assets held for sale (165,526)  
Other 644 (14,940)
Balance at ending 1,351,625 1,428,122
Land [Member] | Accumulated depreciation, amortisation and impairment [Member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Balance at beginning (6,927) (6,985)
Sales or disposal 494 1,244
Foreign currency translation adjustments (262) (94)
Transfer to assets held for sale 424  
Other (794) (1,091)
Balance at ending (7,065) (6,927)
Buildings [Member] | Gross carrying amount [Member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Balance at beginning 6,170,063 5,884,749
Additions 122,961 74,469
Sales or disposal (69,841) (60,228)
Reclassification from construction in progress 312,901 292,601
Foreign currency translation adjustments 184,418 (47,461)
Transfer to assets held for sale (428,406)  
Other (7,190) 25,932
Balance at ending 6,284,907 6,170,063
Buildings [Member] | Accumulated depreciation, amortisation and impairment [Member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Balance at beginning (3,867,037) (3,753,786)
Depreciation (219,752) (169,778)
Impairment losses (3,981)  
Sales or disposal 59,041 52,062
Foreign currency translation adjustments (110,778) 30,142
Transfer to assets held for sale 260,039  
Other (2,135) (25,678)
Balance at ending (3,884,604) (3,867,037)
Machinery and equipment [Member] | Gross carrying amount [Member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Balance at beginning 16,621,243 16,469,032
Additions 468,039 295,719
Sales or disposal (615,221) (561,258)
Reclassification from construction in progress 882,157 572,844
Foreign currency translation adjustments 865,647 (154,892)
Transfer to assets held for sale (698,884)  
Other (13,603) (202)
Balance at ending 17,509,377 16,621,243
Machinery and equipment [Member] | Accumulated depreciation, amortisation and impairment [Member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Balance at beginning (13,157,598) (12,719,614)
Depreciation (1,015,844) (1,039,696)
Impairment losses (4,844)  
Sales or disposal 540,537 516,767
Foreign currency translation adjustments (671,336) 109,227
Transfer to assets held for sale 566,214  
Other (16,190) (24,281)
Balance at ending (13,759,061) (13,157,598)
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 8,051,945 7,523,911
Additions 3,657,892 3,866,922
Sales or disposal (2,620,534) (3,185,673)
Reclassification from construction in progress 55 187
Foreign currency translation adjustments 677,356 (94,981)
Transfer to assets held for sale (652)  
Other (60,414) (58,420)
Balance at ending 9,705,647 8,051,945
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 (1,498,586) (1,619,009)
Depreciation (980,258) (896,127)
Sales or disposal 745,050 983,818
Foreign currency translation adjustments (117,577) 15,759
Transfer to assets held for sale 4  
Other 1,273 16,972
Balance at ending (1,850,094) (1,498,586)
Construction in progress [Member] | Gross carrying amount [Member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Balance at beginning 1,596,145 1,040,188
Additions 1,503,710 1,501,327
Sales or disposal (44,327) (22,473)
Reclassification from construction in progress (1,252,842) (881,473)
Foreign currency translation adjustments 89,663 (19,444)
Transfer to assets held for sale (15,502)  
Other (157,040) (21,979)
Balance at ending 1,719,808 1,596,145
Construction in progress [Member] | Accumulated depreciation, amortisation and impairment [Member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Balance at beginning (3,678) (2,510)
Foreign currency translation adjustments (63) 55
Transfer to assets held for sale 172  
Other 393 (1,223)
Balance at ending ¥ (3,175) ¥ (3,678)