v3.26.1
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
Jun. 30, 2026
Mar. 31, 2026
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Assets measured at amortized cost $ 685,931 $ 570,844
Accumulated impairment loss (495) (376)
Unrealized loss accumulated in other comprehensive (loss)/income including foreign currency translation adjustments, net 1,348 3,570
Assets measured at fair value 686,784 574,038
Corporate debt    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Assets measured at amortized cost 419,121 304,548
Accumulated impairment loss 0 0
Unrealized loss accumulated in other comprehensive (loss)/income including foreign currency translation adjustments, net 3,569 7,056
Assets measured at fair value 422,690 311,604
Non-US sovereign debt    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Assets measured at amortized cost 244,687 244,312
Accumulated impairment loss (495) (376)
Unrealized loss accumulated in other comprehensive (loss)/income including foreign currency translation adjustments, net (2,183) (3,483)
Assets measured at fair value 242,009 240,453
U.S. sovereign debt    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Assets measured at amortized cost 22,123 21,984
Accumulated impairment loss 0 0
Unrealized loss accumulated in other comprehensive (loss)/income including foreign currency translation adjustments, net (38) (3)
Assets measured at fair value $ 22,085 $ 21,981