v3.26.1
Income Taxes - Schedule of Reconciliation of Income Tax Expense (Details) - USD ($)
$ in Thousands
12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Amount      
Statutory tax rate $ 0 $ 0 $ 0
Foreign rate differential   (112,413) 1,196,877
Nondeductible/(nontaxable) changes in the fair value of investments and loss from equity method investments   (12,813) 15,431
Taxable intercompany income/(deductible intercompany expense) (123,074)    
Nondeductible changes in the fair value of the Earn-Out Shares   (27,597) (1,337,102)
Valuation allowance   134,855 43,754
Other   (2,058) 0
Intercompany reorganization 138,465    
Reversal of certain deferred tax assets   25,062 87,262
Nondeductible executive compensation   54,558 19,727
Tax deficiencies (excess tax benefits) from stock-based compensation   (16,676) (21,668)
Research tax credits   (31,840) (22,863)
Permanent disallowed IPR&D   0 0
Other permanent adjustments   37,096 40,085
Total income tax expense $ 133,329 $ 48,174 $ 21,503
Percent      
Income tax benefit at Bermuda statutory tax rate 0.00% 0.00% 0.00%
Foreign rate differential   16.50% 26.20%
Nondeductible/(nontaxable) changes in the fair value of investments and loss from equity method investments   1.90% 0.30%
Taxable intercompany income/(deductible intercompany expense) 46.50%    
Nondeductible changes in the fair value of the Earn-Out Shares   4.00% (29.30%)
Valuation allowance   (19.80%) 1.00%
Other   0.30% 0.00%
Intercompany reorganization (52.30%)    
Reversal of certain deferred tax assets   (3.70%) 2.00%
Nondeductible executive compensation   (0.080) 0.004
Tax deficiencies (excess tax benefits) from stock-based compensation   2.40% (0.50%)
Research tax credits   4.70% (0.50%)
Permanent disallowed IPR&D   0.00% 0.00%
Other permanent adjustments   (5.40%) 0.90%
Total income tax expense (50.40%) (7.10%) 0.50%
United Kingdom      
Amount      
Foreign rate differential $ 16,177    
Nondeductible/(nontaxable) changes in the fair value of investments and loss from equity method investments (27,488)    
Nontaxable income (16,606)    
Nondeductible changes in the fair value of the Earn-Out Shares 11,926    
Valuation allowance 142,562    
Other $ (3,524)    
Percent      
Foreign rate differential (6.10%)    
Nondeductible/(nontaxable) changes in the fair value of investments and loss from equity method investments 10.40%    
Nontaxable income 6.30%    
Nondeductible changes in the fair value of the Earn-Out Shares (4.50%)    
Valuation allowance (53.90%)    
Other 1.30%    
Switzerland      
Amount      
Foreign rate differential $ 2,086    
Valuation allowance (112,256)    
Other 544    
Cantonal and communal taxes 39,289    
Deductible federal taxes (13,590)    
Reversal of certain deferred tax assets $ 25,351    
Percent      
Foreign rate differential (0.80%)    
Valuation allowance 42.40%    
Other (0.20%)    
Cantonal and communal taxes (14.80%)    
Deductible federal taxes 0.051    
Reversal of certain deferred tax assets (9.60%)    
United States      
Amount      
Foreign rate differential $ (74,930)    
Taxable intercompany income/(deductible intercompany expense) 160,909    
Valuation allowance 44,916    
Other 7,888    
Nondeductible executive compensation 60,323    
Tax deficiencies (excess tax benefits) from stock-based compensation (34,482)    
Foreign-derived intangible income (26,310)    
Income/(loss) from disregarded entities (64,511)    
Research tax credits $ (20,336)    
Percent      
Foreign rate differential 28.30%    
Taxable intercompany income/(deductible intercompany expense) (60.80%)    
Valuation allowance (17.00%)    
Other (2.90%)    
Nondeductible executive compensation (0.228)    
Tax deficiencies (excess tax benefits) from stock-based compensation 13.00%    
Foreign-derived intangible income 9.90%    
Income/(loss) from disregarded entities 24.40%    
Research tax credits 7.70%