XML 57 R59.htm IDEA: XBRL DOCUMENT v2.4.0.6
Amortized Cost Basis Amounts, Gross Unrealized Holding Gains, Gross Unrealized Holding Losses and Fair Values of Available-for-Sale Securities and Held-to-Maturity Securities in Each Major Security Type (Detail) (JPY ¥)
In Millions, unless otherwise specified
Dec. 31, 2011
Mar. 31, 2011
Schedule of Investments [Line Items]    
Amortized cost ¥ 912,714 ¥ 907,480
Gross unrealized gains 31,267 31,642
Gross unrealized losses (16,714) (11,605)
Fair value 927,267 927,517
Available-for-sale securities
    
Schedule of Investments [Line Items]    
Amortized cost 869,047 863,785
Gross unrealized gains 28,249 31,230
Gross unrealized losses (16,714) (11,605)
Fair value 880,582 883,410
Available-for-sale securities | Japanese and foreign government bond securities
    
Schedule of Investments [Line Items]    
Amortized cost 172,405 168,818
Gross unrealized gains 1,083 696
Gross unrealized losses (6) (169)
Fair value 173,482 169,345
Available-for-sale securities | Japanese prefectural and foreign municipal bond securities
    
Schedule of Investments [Line Items]    
Amortized cost 57,861 34,907
Gross unrealized gains 849 153
Gross unrealized losses (66) (92)
Fair value 58,644 34,968
Available-for-sale securities | Corporate debt securities
    
Schedule of Investments [Line Items]    
Amortized cost 307,972 292,836
Gross unrealized gains 2,236 1,287
Gross unrealized losses (3,991) (2,091)
Fair value 306,217 292,032
Available-for-sale securities | Specified bonds issued by SPEs in Japan
    
Schedule of Investments [Line Items]    
Amortized cost 162,386 225,393
Gross unrealized gains 644 46
Gross unrealized losses (634) (3,125)
Fair value 162,396 222,314
Available-for-sale securities | CMBS and RMBS in the U.S., and other asset-backed securities
    
Schedule of Investments [Line Items]    
Amortized cost 101,476 87,898
Gross unrealized gains 2,552 3,819
Gross unrealized losses (3,437) (3,843)
Fair value 100,591 87,874
Available-for-sale securities | Other Debt Securities
    
Schedule of Investments [Line Items]    
Amortized cost 7,586 5,518
Gross unrealized losses   (12)
Fair value 7,586 5,506
Available-for-sale securities | Equity securities
    
Schedule of Investments [Line Items]    
Amortized cost 59,361 48,415
Gross unrealized gains 20,885 25,229
Gross unrealized losses (8,580) (2,273)
Fair value 71,666 71,371
Held-to-maturity Securities | Japanese Government Bond Securities
    
Schedule of Investments [Line Items]    
Amortized cost 43,667 43,695
Gross unrealized gains 3,018 412
Fair value ¥ 46,685 ¥ 44,107