Income Taxes - Reconciliation of Benefit from (Provision for) Income Taxes to Amount Computed by Applying Statutory Federal Income Tax Rate to Income (Loss) before Income Taxes (Detail) - USD ($) $ in Thousands		12 Months Ended
		Mar. 31, 2026		Mar. 31, 2025	Mar. 31, 2024
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
U.S. federal statutory tax rate		$ (22,008)		$ 114,512	$ 250,728
State and local income taxes, net of federal income tax effect		(6,532)	[1]	8,908	28,621
Foreign effective tax rate differential, net of valuation allowance				(9,185)	6,199
Withholding taxes				(6,852)	(4,981)
Tax credits				16,004	28,574
Effect of changes in tax laws or rates enacted in the current period		(10,061)
Global intangible low-taxed income (GILTI)		(43,061)
Inclusion of foreign disregarded entities		(3,451)
Subpart F income		(45,418)
Base Erosion and Anti-Abuse Tax (BEAT)				(30,448)
Effect of cross-border tax laws, other		1,324
Research and development tax credits		10,558
Changes in valuation allowances		48,628
Non-deductible compensation		(3,594)		(2,459)	(5,240)
Non-deductible transaction costs				(40)	(18,911)
Non-deductible meals and entertainment				(1,112)	(1,077)
Stock-based compensation				(12,932)	(12,182)
Nontaxable or nondeductible Items, other		(8,507)
Changes in prior period worldwide unrecognized tax benefits		3,029
Unremitted subsidiary gains		(4,380)		(7,043)	(1,586)
Other		(2,346)		(7,514)	2,256
Total (provision for) benefit from income taxes		$ (116,223)		941	139,474
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. federal statutory tax rate		21.00%
State and local income taxes, net of federal income tax effect, percent	[1]	6.00%
Effect of changes in tax laws or rates enacted in the current period, percent		10.00%
Global intangible low-taxed income (GILTI), percent		41.00%
Inclusion of foreign disregarded entities, percent		3.00%
Subpart F income, percent		43.00%
Effect of cross-border tax laws, other, percent		(1.00%)
Research and development tax credits, percent		(10.00%)
Changes in valuation allowances, percent		(46.00%)
Nondeductible compensation, percent		3.00%
Nontaxable or nondeductible Items, other, percent		8.00%
Changes in unrecognized tax benefits, percent		(3.00%)
Unremitted subsidiary gains, percent		4.00%
Other, percent		2.00%
Effective income tax rate reconciliation, percent, total		111.00%
United Kingdom [Member]
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
Foreign effective tax rate differential, net of valuation allowance		$ (5,053)
Interest on overpaid taxes, net of income tax effect		5,146
Other		$ 5,635
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Statutory tax rate difference		5.00%
Interest on overpaid taxes, net of income tax effect, percent		(5.00%)
Other, percent		(5.00%)
Canada [Member]
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
State and local income taxes, net of federal income tax effect		$ (20,332)
Foreign effective tax rate differential, net of valuation allowance		10,226
Capital gain partial exemption on sale of Navarino UK		12,605
Tax audit adjustments		(5,619)
Withholding taxes		(8,993)
Other		$ (3,050)
Effective Income Tax Rate Reconciliation, Percent [Abstract]
State and local income taxes, net of federal income tax effect, percent		19.00%
Statutory tax rate difference		(10.00%)
Capital gain partial exemption on sale of Navarino UK, percent		(12.00%)
Tax audit adjustments, percent		5.00%
Withholding taxes, perecent		9.00%
Other, percent		3.00%
United States [Member]
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
Changes in valuation allowances				(49,566)	(105,968)
State [Member]
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
Effect of changes in tax laws or rates enacted in the current period				(452)	292
Changes in valuation allowances				$ (10,880)	$ (27,251)
Other Foreign Jurisdictions [Member]
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
Foreign effective tax rate differential, net of valuation allowance		$ (20,969)
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Statutory tax rate difference		20.00%

[1] State taxes in Virginia and Maryland made up the majority (greater than 50 percent) of the tax effect in this category.