Annual report [Section 13 and 15(d), not S-K Item 405]

INVESTMENT SECURITIES - Schedule of present securities assets at fair value, available for sale (Details)

v3.26.1
INVESTMENT SECURITIES - Schedule of present securities assets at fair value, available for sale (Details) - USD ($)
$ in Thousands
Mar. 31, 2026
Mar. 31, 2025
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Total trading securities $ 2,339,100 $ 2,275,286
Total available-for-sale securities, at fair value $ 574,038 $ 473,587
Non-US sovereign debt    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Trade securities, weighted average interest rate 10.06% 11.24%
Total trading securities $ 1,337,577 $ 1,282,450
Available-for-sale securities, weighted average interest rate 8.85% 9.96%
Total available-for-sale securities, at fair value $ 240,453 $ 208,231
Corporate debt    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Trade securities, weighted average interest rate 16.80% 13.93%
Total trading securities $ 793,850 $ 807,985
Available-for-sale securities, weighted average interest rate 16.41% 14.81%
Total available-for-sale securities, at fair value $ 311,604 $ 243,730
Corporate equity    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Trade securities, weighted average interest rate 0.00% 0.00%
Total trading securities $ 166,394 $ 106,227
US sovereign debt    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Trade securities, weighted average interest rate 3.89% 3.99%
Total trading securities $ 33,060 $ 73,787
Available-for-sale securities, weighted average interest rate 2.03% 2.73%
Total available-for-sale securities, at fair value $ 21,981 $ 21,626
Exchange traded notes    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Trade securities, weighted average interest rate 0.00% 0.00%
Total trading securities $ 8,219 $ 4,837
Quoted Prices in Active Markets for Identical Assets    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Total trading securities 1,416,580 1,444,746
Total available-for-sale securities, at fair value 227,144 241,935
Quoted Prices in Active Markets for Identical Assets | Non-US sovereign debt    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Total trading securities 693,830 987,657
Total available-for-sale securities, at fair value 74,055 128,772
Quoted Prices in Active Markets for Identical Assets | Corporate debt    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Total trading securities 542,401 299,123
Total available-for-sale securities, at fair value 131,108 91,537
Quoted Prices in Active Markets for Identical Assets | Corporate equity    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Total trading securities 141,270 81,810
Quoted Prices in Active Markets for Identical Assets | US sovereign debt    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Total trading securities 33,060 73,787
Total available-for-sale securities, at fair value 21,981 21,626
Quoted Prices in Active Markets for Identical Assets | Exchange traded notes    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Total trading securities 6,019 2,369
Significant Other Observable Inputs    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Total trading securities 900,245 812,220
Total available-for-sale securities, at fair value 346,894 231,652
Significant Other Observable Inputs | Non-US sovereign debt    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Total trading securities 643,747 294,793
Total available-for-sale securities, at fair value 166,398 79,459
Significant Other Observable Inputs | Corporate debt    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Total trading securities 250,371 508,862
Total available-for-sale securities, at fair value 180,496 152,193
Significant Other Observable Inputs | Corporate equity    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Total trading securities 3,927 6,097
Significant Other Observable Inputs | US sovereign debt    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Total trading securities 0 0
Total available-for-sale securities, at fair value 0 0
Significant Other Observable Inputs | Exchange traded notes    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Total trading securities 2,200 2,468
Significant unobservable units    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Total trading securities 22,275 18,320
Total available-for-sale securities, at fair value 0 0
Significant unobservable units | Non-US sovereign debt    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Total trading securities 0 0
Total available-for-sale securities, at fair value 0 0
Significant unobservable units | Corporate debt    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Total trading securities 1,078 0
Total available-for-sale securities, at fair value 0 0
Significant unobservable units | Corporate equity    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Total trading securities 21,197 18,320
Significant unobservable units | US sovereign debt    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Total trading securities 0 0
Total available-for-sale securities, at fair value 0 0
Significant unobservable units | Exchange traded notes    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Total trading securities $ 0 $ 0