Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Jul. 31, 2020	Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2015
Current Provision [Abstract]
US - Federal		$ (6,631)	$ 1,145	$ 2,384
International		43,269	37,494	52,518
State and local		1,359	172	2,536
Total current provision		37,997	38,811	57,438
Deferred (benefit) provision [Abstract]
US - Federal		(11,996)	(8,476)	335
International		1,175	(15,022)	(7,630)
State and local		480	(4,118)	(5,454)
Total deferred (benefit)		(10,341)	(27,616)	(12,749)
Total provision		27,656	11,195	44,689
Foreign and domestic pretax income (loss) [Abstract]
International		202,490	104,185	204,326
United States		(26,578)	(167,277)	8,626
Income (loss) before taxes		$ 175,912	$ (63,092)	$ 212,952
Effective income tax rate reconciliation [Abstract]
US federal statutory rate		21.00%	21.00%	21.00%	35.00%
Cost of higher taxes on non-US income		1.10%	4.80%	0.90%
State income taxes, net of US federal tax benefit		0.80%	3.30%	(1.30%)
US NOL carryback under CARES Act		(8.00%)	0.00%	0.00%
Deferred tax (benefit) from US Tax Act		0.00%	0.00%	0.10%
Tax credits and related benefits		(0.50%)	(1.10%)	(0.80%)
Impairment of goodwill and intangibles		0.00%	(42.30%)	0.00%
Other		1.30%	(3.40%)	1.10%
Effective income tax rate		15.70%	(17.70%)	21.00%
Refund in connection with NOL carryback		$ 20,700
Tax benefit resulting from NOL carryback		14,000
Increase in official UK statutory rate		$ 3,500
Increase in official UK statutory rate		2.00%
Increase in state income tax expense due to increase in deferred tax liabilities		$ 3,200
Increase in state income tax expense due to increase in deferred tax liabilities		1.80%
Accounting for uncertainty in income taxes [Abstract]
Accruals for interest and penalties		$ 700	$ 600
Interest expense on reserves for unrecognized and recognized tax benefits		200	200
Total amount of unrecognized tax benefits that, if recognized, would reduce the Company's income tax provision		7,400	6,200
Reconciliation of unrecognized tax benefits [Roll Forward]
Balance, beginning of period	$ 6,194	6,194	7,659
Additions for current year tax positions		3,626	694
Additions for prior year tax positions		511	0
Reductions for prior year tax positions		(163)	(655)
Foreign translation adjustment			(15)
Foreign translation adjustment		57
Payments and settlements		(215)	(56)
Reductions for lapse of statute of limitations		(866)	(1,433)
Balance, end of period		9,144	6,194	$ 7,659
Significant components of deferred tax assets and liabilities [Abstract]
Net operating losses		19,433	17,966
Reserve for sales returns and doubtful accounts		3,838	2,638
Accrued employee compensation		32,835	20,114
Foreign and federal credits		5,129	31,487
Other accrued expenses		16,092	11,827
Retirement and post-employment benefits		30,039	37,927
Total gross deferred tax assets		107,366	121,959
Less valuation allowance		(4,855)	(23,287)
Total deferred tax assets		102,511	98,672
Prepaid expenses and other current assets		(459)	(1,142)
Unremitted foreign earnings		(2,485)	(1,985)
Intangible and fixed assets		(260,559)	(205,882)
Total deferred tax liabilities		(263,503)	(209,009)
Net deferred tax liabilities		(160,992)	(110,337)
Reported As [Abstract]
Deferred tax assets		11,911	8,790
Deferred tax liabilities		(172,903)	(119,127)
Net deferred tax liabilities		(160,992)	$ (110,337)
UK [Member]
Income Taxes [Abstract]
Non-cash deferred tax expense from re-measurement of net deferred tax liabilities	$ 3,500
UK [Member] | Minimum [Member]
Income Taxes [Abstract]
Foreign statutory tax rate	17.00%
UK [Member] | Maximum [Member]
Income Taxes [Abstract]
Foreign statutory tax rate	19.00%
US [Member]
Income Taxes [Abstract]
Non-cash deferred tax expense from re-measurement of net deferred tax liabilities		3,200
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Estimated taxes upon repatriation		2,500
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Apportioned state net operating loss carryforwards		115,000
Apportioned state net operating loss carryforwards, tax effected value		$ 6,500
State and Local Jurisdiction [Member] | Minimum [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards, expiration period		5 years
State and Local Jurisdiction [Member] | Maximum [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards, expiration period		19 years