XML 72 R57.htm IDEA: XBRL DOCUMENT v3.7.0.1
Fair value measurements - Additional information (Detail) - JPY (¥)
¥ in Billions
 12 Months Ended
Mar. 31, 2017
Mar. 31, 2016
Mar. 31, 2015
Valuation techniques by major class of financial instrument      
Amount of discount or liquidity adjustment in inactive markets  
Valuation adjustment to reflect own creditworthiness 10 23  
Investment in the common stock at fair value through election of the fair value option      
Gains (losses) from changes in fair value of the financial liabilities for which the fair value option was elected, attributable to the change in creditworthiness 15 23 ¥ 2
Differences between the fair value of the aggregate unpaid principal balance (which is contractually principally protected) of loans and receivables, more (less) than the principal balance of such loans and receivables 0 1  
Differences between the fair value of the aggregate unpaid principal balance (which is contractually principally protected) of long-term borrowings more (less) than the principal balance of such long-term borrowings ¥ 41 ¥ 2  
Concentrations of credit risk, percentage 15.00% 20.00%  
Amount of impairment losses within Non-interest expenses-Other   ¥ 2  
Carrying amount of certain listed equity method investments, whichi are recognized impairment losses   ¥ 3  
Ashikaga Holdings Co., Ltd. [Member]      
Investment in the common stock at fair value through election of the fair value option      
Percentage of common stock   36.90% 37.10%
American Century Companies, Inc. [Member]      
Investment in the common stock at fair value through election of the fair value option      
Percentage of economic interest 39.70%    
Recurring | Financial assets (excluding derivative assets) [Member]      
Transfers Between Level 1 and Level 2      
Transfer from Level 1 to Level 2, Assets ¥ 464 ¥ 85  
Transfer from Level 2 to Level 1, Assets 550 87  
Recurring | Trading assets and private equity investments [Member] | Equities [Member]      
Transfers Between Level 1 and Level 2      
Transfer from Level 1 to Level 2, Assets 423 65  
Transfer from Level 2 to Level 1, Assets 387 60  
Recurring | Trading assets and private equity investments [Member] | Investment trust funds and other [Member]      
Transfers Between Level 1 and Level 2      
Transfer from Level 1 to Level 2, Assets 40 20  
Transfer from Level 2 to Level 1, Assets 13 21  
Recurring | Other [Member]      
Transfers Between Level 1 and Level 2      
Transfer from Level 2 to Level 1, Assets 143    
Recurring | Trading liabilities [Member] | Short sales of equities [Member]      
Transfers Between Level 1 and Level 2      
Transfer from Level 1 to Level 2, Liabilities 452 27  
Transfer from Level 2 to Level 1, Liabilities 341 24  
Recurring | Trading liabilities [Member] | Short sales of Investment trust funds and other [Member]      
Transfers Between Level 1 and Level 2      
Transfer from Level 1 to Level 2, Assets 14    
Recurring | Other liabilities [Member]      
Transfers Between Level 1 and Level 2      
Transfer from Level 2 to Level 1, Liabilities 141    
Recurring | Financial liabilities (excluding derivative liabilities) [Member]      
Transfers Between Level 1 and Level 2      
Transfer from Level 1 to Level 2, Liabilities 466 28  
Transfer from Level 2 to Level 1, Liabilities 483 25  
Recurring | Level 3 [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, assets [1] 78 38  
Transfers out of Level 3, liabilities [1] 134 111  
Transfers into Level 3, Assets [1] 125 102  
Transfers into Level 3, Liabilities [1] 143 125  
Recurring | Level 3 [Member] | Financial assets (excluding derivative assets) [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, assets 62 42  
Transfers into Level 3, Assets 118 111  
Recurring | Level 3 [Member] | Trading assets and private equity investments [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, assets [1] 47 42  
Transfers into Level 3, Assets [1] 92 103  
Recurring | Level 3 [Member] | Trading assets and private equity investments [Member] | Equities [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, assets [1] 7 2  
Transfers into Level 3, Assets [1] 9 2  
Recurring | Level 3 [Member] | Trading assets and private equity investments [Member] | Private equity investments [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, assets [1] 1 6  
Transfers into Level 3, Assets [1]  
Recurring | Level 3 [Member] | Trading assets and private equity investments [Member] | Japanese agency and municipal securities [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, assets [1] 0  
Transfers into Level 3, Assets [1] 0  
Recurring | Level 3 [Member] | Trading assets and private equity investments [Member] | Foreign government, agency and municipal securities [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, assets [1] 4 1  
Transfers into Level 3, Assets [1] 5 3  
Recurring | Level 3 [Member] | Trading assets and private equity investments [Member] | Bank and corporate debt securities and loans for trading purposes [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, assets [1] 27 23  
Transfers into Level 3, Assets [1] 62 60  
Recurring | Level 3 [Member] | Trading assets and private equity investments [Member] | Commercial mortgage-backed securities ("CMBS") [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, assets [1] 0  
Transfers into Level 3, Assets [1] 0 1  
Recurring | Level 3 [Member] | Trading assets and private equity investments [Member] | Residential mortgage-backed securities ("RMBS") [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, assets [1] 1  
Transfers into Level 3, Assets [1] 0 8  
Recurring | Level 3 [Member] | Trading assets and private equity investments [Member] | Real estate-backed securities [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, assets [1]  
Transfers into Level 3, Assets [1] 13  
Recurring | Level 3 [Member] | Trading assets and private equity investments [Member] | Collateralized debt obligations ("CDOs") and other [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, assets [1] 7 7  
Transfers into Level 3, Assets [1] 16 16  
Recurring | Level 3 [Member] | Trading assets and private equity investments [Member] | Investment trust funds and other [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, assets [1] 0 3  
Transfers into Level 3, Assets [1] 0 0  
Recurring | Level 3 [Member] | Equity contracts [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, assets [1],[2] 11 (4)  
Transfers into Level 3, Assets [1],[2] 22 1  
Recurring | Level 3 [Member] | Interest rate contracts [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, assets [1],[2] 9 1  
Transfers into Level 3, Assets [1],[2] (15) (1)  
Recurring | Level 3 [Member] | Credit contracts [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, assets [1],[2] 0 (7)  
Transfers into Level 3, Assets [1],[2] (4) (6)  
Recurring | Level 3 [Member] | Foreign exchange contracts [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, assets [1],[2] (4) 6  
Transfers into Level 3, Assets [1],[2] 4 (3)  
Recurring | Level 3 [Member] | Commodity contracts [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, assets [1],[2]  
Transfers into Level 3, Assets [1],[2]  
Recurring | Level 3 [Member] | Derivatives, net [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, assets [1],[2] 16 (4)  
Transfers into Level 3, Assets [1],[2] 7 (9)  
Recurring | Level 3 [Member] | Loans and receivables [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, assets [1] 5  
Transfers into Level 3, Assets [1] 14 8  
Recurring | Level 3 [Member] | Non-trading debt securities [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, assets [1]  
Transfers into Level 3, Assets [1]  
Recurring | Level 3 [Member] | Other [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, assets [1] 10 0  
Transfers into Level 3, Assets [1] 7 0  
Recurring | Level 3 [Member] | Trading liabilities [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, liabilities [1] 5 3  
Transfers into Level 3, Liabilities [1] 3 2  
Recurring | Level 3 [Member] | Trading liabilities [Member] | Equities [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, liabilities [1] 3 2  
Transfers into Level 3, Liabilities [1] 3 1  
Recurring | Level 3 [Member] | Trading liabilities [Member] | Bank and corporate debt securities [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, liabilities [1] 2 1  
Transfers into Level 3, Liabilities [1] 0 1  
Recurring | Level 3 [Member] | Trading liabilities [Member] | Collateralized debt obligations ("CDOs") and other [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, liabilities [1] 0    
Transfers into Level 3, Liabilities [1]    
Recurring | Level 3 [Member] | Trading liabilities [Member] | Investment trust funds and other [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, liabilities [1] 0  
Transfers into Level 3, Liabilities [1] 0  
Recurring | Level 3 [Member] | Short-term borrowings [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, liabilities [1] 4 17  
Transfers into Level 3, Liabilities [1] 7 9  
Recurring | Level 3 [Member] | Payables and deposits [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, liabilities [1] 0  
Transfers into Level 3, Liabilities [1]  
Recurring | Level 3 [Member] | Long-term borrowings [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, liabilities [1] 125 91  
Transfers into Level 3, Liabilities [1] 132 114  
Recurring | Level 3 [Member] | Other liabilities [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, liabilities [1] 0 0  
Transfers into Level 3, Liabilities [1] 1 0  
Recurring | Level 3 [Member] | Financial liabilities (excluding derivative liabilities) [Member]      
Transfers out of / into Level 3      
Transfers out of Level 3, liabilities 134 111  
Transfers into Level 3, Liabilities ¥ 143 ¥ 125  
[1] If financial instruments move from Level 3 to another Level or move from another Level to Level 3, the amount reported in Transfers into Level 3 and Transfers out of Level 3 is the fair value as of the beginning of the quarter during which the movement occurs. Therefore if financial instruments move from another Level to Level 3, all gains/ (losses) during the quarter are included in the table and if financial instruments move from Level 3 to another Level, all gains/ (losses) during the year are excluded from the table.
[2] Each derivative classification includes derivatives with multiple risk underlyings. For example, interest rate contracts include complex derivatives referencing interest rate risk as well as foreign exchange risk or other factors such as prepayment rates. Credit contracts include credit default swaps as well as derivatives referencing corporate and government debt securities.