Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Apr. 30, 2023	Apr. 30, 2022	Apr. 30, 2021	Apr. 30, 2020
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 19,284,000	$ 6,059,000	$ 7,720,000
Recognize penalties and interests accrued on unrecognized tax benefits (less than)	200,000	300,000	100,000
Accrued interest and penalties, amount	200,000	300,000
Dividend withholding tax from foreign jurisdictions	3,100,000
Deferred Tax Assets, Valuation Allowance	(575,557,000)	(498,996,000)
Net operating loss carryforward	533,051,000	458,733,000
Tax credits	28,048,000	28,467,000
Unrecognized tax benefits	18,157,000	16,622,000	13,656,000	$ 9,706,000
Unrecognized tax benefits that would impact the effective tax rate before consideration of valuation allowance	0
Operating Loss Carryforwards [Line Items]
Valuation allowance for deferred tax assets	575,557,000	498,996,000
Net operating loss carryforward	533,051,000	458,733,000
Tax credits	28,048,000	28,467,000
Unrecognized tax benefits	18,157,000	16,622,000	$ 13,656,000	$ 9,706,000
Unrecognized tax benefits that would impact the effective tax rate before consideration of valuation allowance	0
Valuation Allowance [Line Items]
Valuation allowance for deferred tax assets	575,557,000	498,996,000
Canada Revenue Agency
Income Tax Disclosure [Abstract]
Tax credits	600,000
Operating Loss Carryforwards [Line Items]
Tax credits	600,000
Dutch | Tax and Customs Administration, Netherlands
Income Tax Disclosure [Abstract]
Net operating loss carryforward	1,000,000,000
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward	1,000,000,000
U.S. Federal | IRS
Income Tax Disclosure [Abstract]
Net operating loss carryforward	973,400,000
Tax credits	20,400,000
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward	973,400,000
Tax credits	20,400,000
U.S. Federal | Her Majesty's Revenue and Customs (HMRC)
Income Tax Disclosure [Abstract]
Net operating loss carryforward	74,500,000
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward	74,500,000
U.S. State Income Tax
Income Tax Disclosure [Abstract]
Net operating loss carryforward	665,000,000
Tax credits	5,800,000
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward	665,000,000
Tax credits	5,800,000
NETHERLANDS
Income Tax Disclosure [Abstract]
Deferred Tax Assets, Valuation Allowance	(283,300,000)	(203,200,000)
Valuation allowance, net deferred tax assets, jurisdictions increased	80,100,000	53,800,000
Operating Loss Carryforwards [Line Items]
Valuation allowance for deferred tax assets	283,300,000	203,200,000
Valuation allowance, net deferred tax assets, jurisdictions increased	80,100,000	53,800,000
Valuation Allowance [Line Items]
Valuation allowance for deferred tax assets	283,300,000	203,200,000
United Kingdom
Income Tax Disclosure [Abstract]
Deferred Tax Assets, Valuation Allowance	(19,500,000)	(19,500,000)
Valuation allowance, net deferred tax assets, jurisdictions increased	100,000	5,100,000
Operating Loss Carryforwards [Line Items]
Valuation allowance for deferred tax assets	19,500,000	19,500,000
Valuation allowance, net deferred tax assets, jurisdictions increased	100,000	5,100,000
Valuation Allowance [Line Items]
Valuation allowance for deferred tax assets	19,500,000	19,500,000
United States
Income Tax Disclosure [Abstract]
Deferred Tax Assets, Valuation Allowance	(272,700,000)	(276,300,000)
Valuation allowance, net deferred tax assets, jurisdictions increased	3,600,000	30,300,000
Operating Loss Carryforwards [Line Items]
Valuation allowance for deferred tax assets	272,700,000	276,300,000
Valuation allowance, net deferred tax assets, jurisdictions increased	3,600,000	30,300,000
Valuation Allowance [Line Items]
Valuation allowance for deferred tax assets	272,700,000	$ 276,300,000
Other countries
Income Tax Disclosure [Abstract]
Cumulative earnings	146,300,000
Operating Loss Carryforwards [Line Items]
Cumulative earnings	$ 146,300,000