Quarterly report [Sections 13 or 15(d)]

INVESTMENT SECURITIES - Schedule of amortized cost, unrealized gains and losses accumulated in other comprehensive income, and fair value of available-for-sale securities (Details)

v3.25.3
INVESTMENT SECURITIES - Schedule of amortized cost, unrealized gains and losses accumulated in other comprehensive income, and fair value of available-for-sale securities (Details) - USD ($)
$ in Thousands
Sep. 30, 2025
Mar. 31, 2025
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Assets measured at amortized cost $ 446,079 $ 477,156
Accumulated impairment loss (388) (406)
Unrealized gain/(loss) accumulated in other comprehensive income/(loss) including foreign currency translation adjustments, net (5,890) (3,163)
Assets measured at fair value 439,801 473,587
Corporate debt    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Assets measured at amortized cost 198,580 243,660
Accumulated impairment loss 0 (28)
Unrealized gain/(loss) accumulated in other comprehensive income/(loss) including foreign currency translation adjustments, net (904) 98
Assets measured at fair value 197,676 243,730
Non-US sovereign debt    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Assets measured at amortized cost 225,572 211,628
Accumulated impairment loss (388) (378)
Unrealized gain/(loss) accumulated in other comprehensive income/(loss) including foreign currency translation adjustments, net (4,970) (3,019)
Assets measured at fair value 220,214 208,231
U.S. sovereign debt    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Assets measured at amortized cost 21,927 21,868
Accumulated impairment loss 0 0
Unrealized gain/(loss) accumulated in other comprehensive income/(loss) including foreign currency translation adjustments, net (16) (242)
Assets measured at fair value $ 21,911 $ 21,626