Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2019
Cash flows from operating activities:
Net income	$ 105,560	$ 23,381	$ 56,002
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	108,125	116,533	117,459
Impairment of goodwill	0	63,074	0
Write-off and amortization of debt discount and debt issuance costs	7,568	4,541	3,332
Equity-based compensation	12,872	8,970	7,643
(Gain) loss on disposal and impairment of assets	(1,011)	658	(525)
Change in fair value of financial instruments	0	0	6,395
Deferred income taxes	(10,329)	926	(17,487)
Other items, net	1,552	4,110	5,984
Changes in assets and liabilities net of effects of acquisitions:
Trade accounts and notes receivable	(101,617)	50,215	(18,039)
Inventories	(46,660)	(4,579)	5,137
Prepaid expenses and other assets	(2,621)	6,623	(4,842)
Accounts payable	65,446	31,499	31,269
Accrued compensation and employee benefits	4,477	4,740	6,631
Other accrued expenses and liabilities	9,942	(7,612)	(5,344)
Cash provided by operating activities	153,304	303,079	193,615
Cash flows from investing activities:
Purchases of property and equipment	(29,873)	(25,193)	(18,770)
Proceeds from sale of assets	2,262	2,229	1,170
Acquisition of businesses, net of cash acquired	(35,976)	(24,136)	(583,092)
Cash used in investing activities	(63,587)	(47,100)	(600,692)
Cash flows from financing activities:
Repayments on revolving credit facilities	(102,189)	(837,424)	(937,176)
Borrowings from revolving credit facilities	14,750	880,698	981,148
Payments of principal on long-term debt	(8,754)	(109,968)	(9,968)
Payments of principal on finance lease obligations	(30,371)	(25,275)	(19,474)
Borrowings from term loan	511,000	0	996,840
Repayments of term loan	(869,427)	0	(571,840)
Issuance of Senior Notes	350,000	0	0
Repurchases of common stock	(4,160)	0	(16,520)
Payments for contingent consideration	0	(11,133)	0
Debt issuance costs	(6,299)	(1,286)	(7,933)
Proceeds from exercises of stock options	7,559	11,793	2,538
Payments for taxes related to net share settlement of equity awards	(807)	(532)	(50)
Proceeds from issuance of stock pursuant to employee stock purchase plan	2,076	1,793	1,405
Cash (used in) provided by financing activities	(136,622)	(91,334)	418,970
Effect of exchange rates on cash and cash equivalents	3,008	(1,074)	(992)
(Decrease) increase in cash and cash equivalents	(43,897)	163,571	10,901
Cash and cash equivalents, beginning of year	210,909	47,338	36,437
Cash and cash equivalents, end of year	167,012	210,909	47,338
Supplemental cash flow disclosures:
Cash paid for income taxes	46,417	29,761	19,351
Cash paid for interest	49,650	63,745	66,435
Supplemental schedule of noncash activities:
Assets acquired under finance lease	27,400	50,484	111,826
Issuance of installment notes associated with equity-based compensation liability awards	$ 590	$ 5,163	$ 5,356