Segments - Reconciliation of Net Income to Adjusted EBITDA (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Segments
Net income	$ (41,456)	$ 10,879	$ 29,138	$ 24,820	$ 16,625	$ 5,815	$ 24,912	$ 8,650	$ 23,381	$ 56,002	$ 62,971
Interest expense									67,718	73,677	31,395
Write-off of debt discount and deferred financing fees									1,331		74
Interest income									(88)	(66)	(177)
Provision for income taxes									22,944	14,039	20,883
Depreciation expense									51,332	46,456	24,075
Amortization expense									65,201	71,003	41,455
Impairment of goodwill	63,100								63,074
Stock appreciation expense									1,572	2,730	2,318
Redeemable noncontrolling interests									520	1,188	1,868
Equity-based compensation									7,060	3,906	1,695
Severance and other permitted costs									5,733	8,152	581
Transaction costs (acquisitions and other)									2,414	7,858	3,370
Loss (gain) on disposal and impairment of assets									658	(525)	(509)
Effects of fair value adjustments to inventory									575	4,176	324
Change in fair value of financial instruments								$ 5,700		6,395	6,125
Gain on legal settlement	(14,000)								(14,029)
Secondary public offering costs									363		1,525
Debt transaction costs										678	1,285
Adjusted EBITDA									299,759	$ 295,669	$ 199,258
Impairment	$ 1,900								$ 1,900