v3.26.1
Property, Plant and Equipment - Schedule of Reconciliation of Changes in Property, Plant and Equipment (Details) - JPY (¥)
¥ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning of period ¥ 1,968,209 ¥ 1,989,777
Ending of period 2,120,639 1,968,209
Buildings and structures    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning of period 1,117,720 1,171,629
Ending of period 1,169,518 1,117,720
Machinery and vehicles    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning of period 385,195 395,865
Ending of period 416,109 385,195
Tools, furniture, and fixtures    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning of period 51,587 49,761
Ending of period 53,366 51,587
Land    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning of period 104,119 105,572
Ending of period 108,312 104,119
Construction in progress    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning of period 309,589 266,950
Ending of period 373,334 309,589
Acquisition cost    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning of period 3,273,239 3,210,478
Additions and other increases 200,067 225,155
Transfers 0 0
Disposals and other decreases (58,633) (79,245)
Reclassification to assets held for sale (Note 18) (11,581) (38,803)
Foreign currency translation differences 249,416 (44,345)
Ending of period 3,652,509 3,273,239
Acquisition cost | Buildings and structures    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning of period 1,671,876 1,679,054
Additions and other increases 32,610 37,969
Transfers 31,982 36,236
Disposals and other decreases (15,345) (36,322)
Reclassification to assets held for sale (Note 18) (3,061) (22,552)
Foreign currency translation differences 118,010 (22,509)
Ending of period 1,836,073 1,671,876
Acquisition cost | Machinery and vehicles    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning of period 995,309 981,944
Additions and other increases 24,540 22,271
Transfers 49,066 48,722
Disposals and other decreases (28,536) (29,931)
Reclassification to assets held for sale (Note 18) (7,322) (15,493)
Foreign currency translation differences 78,813 (12,205)
Ending of period 1,111,871 995,309
Acquisition cost | Tools, furniture, and fixtures    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning of period 180,056 164,945
Additions and other increases 10,636 10,480
Transfers 8,640 13,185
Disposals and other decreases (10,213) (5,668)
Reclassification to assets held for sale (Note 18) (1,015) (346)
Foreign currency translation differences 12,798 (2,539)
Ending of period 200,903 180,056
Acquisition cost | Land    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning of period 104,342 105,845
Additions and other increases 274 0
Transfers 56 68
Disposals and other decreases (2,258) 0
Reclassification to assets held for sale (Note 18) (43) (399)
Foreign currency translation differences 6,403 (1,172)
Ending of period 108,774 104,342
Acquisition cost | Construction in progress    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning of period 321,656 278,689
Additions and other increases 132,007 154,435
Transfers (89,744) (98,211)
Disposals and other decreases (2,281) (7,325)
Reclassification to assets held for sale (Note 18) (141) (12)
Foreign currency translation differences 33,392 (5,920)
Ending of period 394,889 321,656
Accumulated depreciation and accumulated impairment losses    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning of period (1,305,030) (1,220,701)
Disposals and other decreases 46,645 52,298
Reclassification to assets held for sale (Note 18) 6,759 25,968
Foreign currency translation differences (91,425) 15,575
Depreciation expenses (173,200) (173,392)
Impairment losses (15,619) (4,778)
Ending of period (1,531,870) (1,305,030)
Accumulated depreciation and accumulated impairment losses | Buildings and structures    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning of period (554,156) (507,425)
Disposals and other decreases 11,481 19,132
Reclassification to assets held for sale (Note 18) 1,005 14,087
Foreign currency translation differences (36,608) 6,892
Depreciation expenses (85,047) (86,344)
Impairment losses (3,230) (498)
Ending of period (666,555) (554,156)
Accumulated depreciation and accumulated impairment losses | Machinery and vehicles    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning of period (610,114) (586,080)
Disposals and other decreases 24,989 24,985
Reclassification to assets held for sale (Note 18) 4,945 11,642
Foreign currency translation differences (43,667) 6,541
Depreciation expenses (68,105) (66,372)
Impairment losses (3,809) (830)
Ending of period (695,761) (610,114)
Accumulated depreciation and accumulated impairment losses | Tools, furniture, and fixtures    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning of period (128,469) (115,184)
Disposals and other decreases 9,840 5,341
Reclassification to assets held for sale (Note 18) 809 192
Foreign currency translation differences (9,395) 1,974
Depreciation expenses (20,048) (20,676)
Impairment losses (273) (116)
Ending of period (147,537) (128,469)
Accumulated depreciation and accumulated impairment losses | Land    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning of period (223) (273)
Disposals and other decreases 0 0
Reclassification to assets held for sale (Note 18) 0 47
Foreign currency translation differences (83) 3
Depreciation expenses 0 0
Impairment losses (156) 0
Ending of period (462) (223)
Accumulated depreciation and accumulated impairment losses | Construction in progress    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning of period (12,068) (11,739)
Disposals and other decreases 334 2,840
Reclassification to assets held for sale (Note 18) 0 0
Foreign currency translation differences (1,672) 166
Depreciation expenses 0 0
Impairment losses (8,150) (3,333)
Ending of period ¥ (21,555) ¥ (12,068)