Basis of Presentation - Narrative (Details) - USD ($)	3 Months Ended						9 Months Ended
	Jan. 31, 2022	Oct. 31, 2021	Jul. 31, 2021	Jan. 31, 2021	Oct. 31, 2020	Jul. 31, 2020	Jan. 31, 2022	Jan. 31, 2021
Finite-Lived Intangible Assets [Line Items]
Operating income	$ 5,224,000			$ 30,279,000			$ 17,213,000	$ 92,549,000
Net income (loss)	$ (49,257,000)	$ 2,030,000	$ 2,981,000	$ 18,445,000	$ 23,122,000	$ 16,059,000	$ (44,246,000)	$ 57,626,000
Earnings per share, basic (in usd per share)	$ (2.97)			$ 1.09			$ (2.67)	$ 3.39
Earnings per share, diluted (in usd per share)	$ (2.97)			$ 1.08			$ (2.67)	$ 3.38
Impairment charges related to goodwill	$ 0			$ 0			$ 0	$ 0
Revision of Prior Period, Change in Accounting Principle, Adjustment
Finite-Lived Intangible Assets [Line Items]
Operating income	4,100,000						9,300,000
Net income (loss)	$ 3,000,000						$ 6,800,000
Earnings per share, basic (in usd per share)	$ 0.18						$ 0.41
Earnings per share, diluted (in usd per share)	$ 0.18						$ 0.41
Other intangible assets
Finite-Lived Intangible Assets [Line Items]
Impairment charges related to other intangible assets	$ 0			$ 0			$ 0	$ 0
Maximum
Finite-Lived Intangible Assets [Line Items]
Intangible assets estimated useful lives							6 years