v3.26.1
Fair value measurements - Schedule of carrying values, fair values and classification within the fair value hierarchy for certain classes of financial instrument (Detail) - JPY (¥)
¥ in Millions
Mar. 31, 2026
Mar. 31, 2025
Liabilities:    
Deposits received at banks ¥ 316,020 ¥ 325,570
Level 1 [Member]    
Assets:    
Cash and cash equivalents [1] 4,299,000 4,424,000
Time deposits [1]
Deposits with stock exchanges and other segregated cash [1]
Loans receivable [1],[2]
Securities purchased under agreements to resell [1]
Securities borrowed [1]
Total Assets [1] 4,299,000 4,424,000
Liabilities:    
Short-term borrowings [1]
Deposits received at banks [1]
Securities sold under agreements to repurchase [1]
Securities loaned [1]
Other secured borrowings [1]
Long-term borrowings [1] 11,000 10,000
Total Liabilities [1] 11,000 10,000
Level 2 [Member]    
Assets:    
Cash and cash equivalents [1]
Time deposits [1] 710,000 642,000
Deposits with stock exchanges and other segregated cash [1] 641,000 448,000
Loans receivable [1],[2] 4,449,000 3,436,000
Securities purchased under agreements to resell [1] 13,195,000 13,991,000
Securities borrowed [1] 4,340,000 4,659,000
Total Assets [1] 23,335,000 23,176,000
Liabilities:    
Short-term borrowings [1] 1,710,000 1,081,000
Deposits received at banks [1] 3,655,000 3,092,000
Securities sold under agreements to repurchase [1] 15,234,000 16,288,000
Securities loaned [1] 2,448,000 1,965,000
Other secured borrowings [1] 384,000 393,000
Long-term borrowings [1] 15,085,000 12,879,000
Total Liabilities [1] 38,516,000 35,698,000
Level 3 [Member]    
Assets:    
Cash and cash equivalents [1]
Time deposits [1]
Deposits with stock exchanges and other segregated cash [1]
Loans receivable [1],[2] 3,291,000 2,584,000
Securities purchased under agreements to resell [1] 15,000 14,000
Securities borrowed [1]
Total Assets [1] 3,306,000 2,598,000
Liabilities:    
Short-term borrowings [1] 43,000 36,000
Deposits received at banks [1] 12,000 14,000
Securities sold under agreements to repurchase [1]
Securities loaned [1]
Other secured borrowings [1]
Long-term borrowings [1] 466,000 496,000
Total Liabilities [1] 521,000 546,000
Carrying value [Member]    
Assets:    
Cash and cash equivalents [1] 4,299,000 4,424,000
Time deposits [1] 710,000 642,000
Deposits with stock exchanges and other segregated cash [1] 641,000 448,000
Loans receivable [1],[2] 7,742,000 6,022,000
Securities purchased under agreements to resell [1] 13,210,000 14,005,000
Securities borrowed [1] 4,340,000 4,659,000
Total Assets [1] 30,942,000 30,200,000
Liabilities:    
Short-term borrowings [1] 1,753,000 1,117,000
Deposits received at banks [1] 3,667,000 3,106,000
Securities sold under agreements to repurchase [1] 15,234,000 16,288,000
Securities loaned [1] 2,448,000 1,965,000
Other secured borrowings [1] 384,000 393,000
Long-term borrowings [1] 15,545,000 13,374,000
Total Liabilities [1] 39,031,000 36,243,000
Fair value [Member]    
Assets:    
Cash and cash equivalents [1] 4,299,000 4,424,000
Time deposits [1] 710,000 642,000
Deposits with stock exchanges and other segregated cash [1] 641,000 448,000
Loans receivable [1],[2] 7,740,000 6,020,000
Securities purchased under agreements to resell [1] 13,210,000 14,005,000
Securities borrowed [1] 4,340,000 4,659,000
Total Assets [1] 30,940,000 30,198,000
Liabilities:    
Short-term borrowings [1] 1,753,000 1,117,000
Deposits received at banks [1] 3,667,000 3,106,000
Securities sold under agreements to repurchase [1] 15,234,000 16,288,000
Securities loaned [1] 2,448,000 1,965,000
Other secured borrowings [1] 384,000 393,000
Long-term borrowings [1] 15,562,000 13,385,000
Total Liabilities [1] ¥ 39,048,000 ¥ 36,254,000
[1] Includes financial instruments which are carried at fair value on a recurring basis.
[2] Carrying values are shown after deducting relevant allowances for credit losses.