v3.26.1
Investments Accounted for Using the Equity Method - Combined Financial Information of Affiliates and Joint Ventures (Detail) - JPY (¥)
¥ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Mar. 31, 2023
Disclosure of investments accounted for using equity method [line items]        
Current assets ¥ 13,074,752 ¥ 11,687,762    
Non-current assets 20,434,533 19,088,105    
Total assets 33,509,285 30,775,867 ¥ 29,774,150  
Current liabilities 10,204,480 8,615,157    
Non-current liabilities 11,156,733 9,532,888    
Total liabilities 21,361,213 18,148,045    
Total equity 12,148,072 12,627,822 13,005,872 ¥ 11,502,291
Sales revenue 21,796,610 21,688,767 20,428,802  
Profit (loss) for the year (353,023) 903,034 1,182,590  
Affiliates [member]        
Disclosure of investments accounted for using equity method [line items]        
Current assets 2,505,736 2,050,076    
Non-current assets 2,780,209 2,813,586    
Total assets 5,285,945 4,863,662    
Current liabilities 1,756,448 1,575,802    
Non-current liabilities 723,793 502,367    
Total liabilities 2,480,241 2,078,169    
Total equity 2,805,704 2,785,493    
Sales revenue 4,544,131 4,623,427 4,614,619  
Profit (loss) for the year 29,411 104,021 53,285  
Affiliates [member] | Motorcycle business [member]        
Disclosure of investments accounted for using equity method [line items]        
Current assets 59,611 46,092    
Non-current assets 21,027 18,217    
Total assets 80,638 64,309    
Current liabilities 23,612 19,386    
Non-current liabilities 2,349 1,919    
Total liabilities 25,961 21,305    
Total equity 54,677 43,004    
Sales revenue 191,970 153,727 178,964  
Profit (loss) for the year 17,069 12,978 12,744  
Affiliates [member] | Automobile business [member]        
Disclosure of investments accounted for using equity method [line items]        
Current assets 2,417,433 1,971,257    
Non-current assets 2,733,794 2,770,810    
Total assets 5,151,227 4,742,067    
Current liabilities 1,726,322 1,549,786    
Non-current liabilities 721,007 499,907    
Total liabilities 2,447,329 2,049,693    
Total equity 2,703,898 2,692,374    
Sales revenue 4,334,184 4,451,855 4,425,320  
Profit (loss) for the year 10,378 87,996 38,348  
Affiliates [member] | Power products and other businesses [member]        
Disclosure of investments accounted for using equity method [line items]        
Current assets 28,692 32,727    
Non-current assets 25,388 24,559    
Total assets 54,080 57,286    
Current liabilities 6,514 6,630    
Non-current liabilities 437 541    
Total liabilities 6,951 7,171    
Total equity 47,129 50,115    
Sales revenue 17,977 17,845 10,335  
Profit (loss) for the year 1,964 3,047 2,193  
Joint ventures [member]        
Disclosure of investments accounted for using equity method [line items]        
Current assets 1,357,010 1,308,190    
Non-current assets 735,663 818,072    
Total assets 2,092,673 2,126,262    
Current liabilities 1,224,322 1,202,957    
Non-current liabilities 144,412 153,497    
Total liabilities 1,368,734 1,356,454    
Total equity 723,939 769,808    
Sales revenue 3,134,885 3,909,385 5,111,037  
Profit (loss) for the year (108,666) (29,396) 168,972  
Joint ventures [member] | Motorcycle business [member]        
Disclosure of investments accounted for using equity method [line items]        
Current assets 423,037 383,566    
Non-current assets 182,897 185,883    
Total assets 605,934 569,449    
Current liabilities 371,144 326,185    
Non-current liabilities 68,951 71,439    
Total liabilities 440,095 397,624    
Total equity 165,839 171,825    
Sales revenue 1,226,487 1,181,238 1,103,578  
Profit (loss) for the year 119,253 108,842 100,242  
Joint ventures [member] | Automobile business [member]        
Disclosure of investments accounted for using equity method [line items]        
Current assets 930,195 919,732    
Non-current assets 551,504 631,036    
Total assets 1,481,699 1,550,768    
Current liabilities 852,346 874,653    
Non-current liabilities 71,904 78,792    
Total liabilities 924,250 953,445    
Total equity 557,449 597,323    
Sales revenue 1,902,570 2,723,204 4,003,276  
Profit (loss) for the year (229,264) (139,636) 67,056  
Joint ventures [member] | Power products and other businesses [member]        
Disclosure of investments accounted for using equity method [line items]        
Current assets 3,778 4,892    
Non-current assets 1,262 1,153    
Total assets 5,040 6,045    
Current liabilities 832 2,119    
Non-current liabilities 3,557 3,266    
Total liabilities 4,389 5,385    
Total equity 651 660    
Sales revenue 5,828 4,943 4,183  
Profit (loss) for the year ¥ 1,345 ¥ 1,398 ¥ 1,674