v3.26.1
Shareholders' Equity - Movements of Other Reserves (Detail) - JPY (¥)
¥ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
At beginning of period ¥ 16,488,594 ¥ 16,279,098 ¥ 13,536,965
Gains (losses) arising during the period, before tax 96,497 (37,183) 50,358
Income tax (expense) benefit for changes arising during the period (289,732) 15,442 (510,012)
Reclassification adjustments for (gains) losses included in net profit, before tax 87,581 15,186 110,509
Gains (losses) arising during the period, before tax 361,685 (32,479) 528,441
Share of other comprehensive income (loss) of associates and joint ventures 19,966 40,492 13,210
Share of other comprehensive income (loss) of associates and joint ventures 3,216 (595) (14)
At end of period 18,288,994 16,488,594 16,279,098
Remeasurements of defined benefit plans [member]      
At beginning of period 87,504 159,724 159,584
Gains (losses) arising during the period, before tax 96,497 (37,183) 50,358
Income tax (expense) benefit for changes arising during the period (30,563) 8,168 (15,485)
Amount attributable to non-controlling interests 24 (102) 44
Share of other comprehensive income (loss) of associates and joint ventures 339 (326) 609
Transfer from other reserves to retained earnings (58,805) (42,777) (35,386)
At end of period 94,996 87,504 159,724
Exchange differences on translating foreign operations [member]      
At beginning of period 1,407,837 1,402,658 884,790
Gains (losses) arising during the period, before tax 361,685 (32,479) 528,441
Income tax (expense) benefit for changes arising during the period 12,231 (216) (3,447)
Reclassification adjustments for (gains) losses included in net profit, before tax 39,944 (640) (11,258)
Income tax (expense) benefit for reclassification adjustments (12,231) 196 3,447
Amount attributable to non-controlling interests (711) 46 (3,324)
Share of other comprehensive income (loss) of associates and joint ventures 18,843 38,272 4,009
At end of period 1,827,598 1,407,837 1,402,658
Financial Assets at Fair Value Through OCI Category [member]      
At beginning of period 2,160,119 2,507,275 1,575,193
Gains (losses) arising during the period, before tax 754,045 7,370 1,506,580
Income tax (expense) benefit for changes arising during the period (238,104) (26,668) (454,951)
Reclassification adjustments for (gains) losses included in net profit, before tax 87,581 15,186 110,509
Income tax benefit for reclassification adjustments (28,007) (5,693) (33,994)
Amount attributable to non-controlling interests 197 (37) (106)
Share of other comprehensive income (loss) of associates and joint ventures 4,000 1,951 8,578
Transfer from other reserves to retained earnings (332,603) (339,265) (204,534)
At end of period ¥ 2,407,228 ¥ 2,160,119 ¥ 2,507,275