Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2017
Cash flows from operating activities:
Net income	$ 56,002	$ 62,971	$ 48,886
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	117,459	65,530	69,240
Write-off and amortization of debt discount and debt issuance costs	3,332	2,851	9,793
Provision for losses on accounts and notes receivable	617	(622)	(122)
Provision for obsolescence of inventory	432	106	425
Effects of fair value adjustments to inventory	4,176	324	946
Increase in fair value of contingent consideration	759	195	(1,484)
Equity-based compensation	7,643	5,745	3,142
Gain on sale and disposal of assets	(525)	(509)	(336)
Change in fair value of financial instruments	6,395	6,125	382
Deferred income taxes	(17,487)	(16,224)	(20,114)
Changes in assets and liabilities net of effects of acquisitions:
Trade accounts and notes receivable	(13,586)	(11,752)	(20,400)
Inventories	5,137	(35,098)	(19,336)
Prepaid expenses and other assets	(4,842)	(3,109)	(1,476)
Accounts payable	26,816	11,365	(3,763)
Accrued compensation and employee benefits	6,631	(236)	4,440
Derivative liability	(10,778)
Other accrued expenses and liabilities	5,434	3,601	(2,308)
Cash provided by operating activities	193,615	91,263	67,915
Cash flows from investing activities:
Purchases of property and equipment	(18,770)	(23,741)	(11,083)
Proceeds from sale of assets	1,170	2,865	3,995
Acquisition of businesses, net of cash acquired	(583,092)	(28,333)	(150,428)
Cash used in investing activities	(600,692)	(49,209)	(157,516)
Cash flows from financing activities:
Repayments on the revolving credit facility	(937,176)	(617,230)	(1,011,925)
Borrowings from the revolving credit facility	981,148	513,878	1,013,365
Payments of principal on long-term debt	(9,968)	(5,776)	(4,584)
Payments of principal on capital lease obligations	(19,474)	(6,132)	(5,208)
Proceeds from issuance of common stock in initial public offering, net of underwriting discounts			156,941
Repayments of term loan			(160,000)
Borrowings from term loan	996,840	577,616	481,225
Repayments from term loan	(571,840)	(477,616)	(381,225)
Repurchases of common stock	(16,520)
Debt issuance costs	(7,933)	(3,283)	(3,844)
Payments for taxes related to net share settlement of equity awards	(50)	(1,441)
Proceeds from exercises of stock options	2,538	477	345
Other financing activities	1,405	(671)
Cash provided by (used in) financing activities	418,970	(20,178)	85,090
Effect of exchange rates on cash and cash equivalents	(992)
Increase (decrease) in cash and cash equivalents	10,901	21,876	(4,511)
Cash and cash equivalents, beginning of year	36,437	14,561	19,072
Cash and cash equivalents, end of year	47,338	36,437	14,561
Supplemental cash flow disclosures:
Cash paid for income taxes	19,351	38,954	49,163
Cash paid for interest	66,435	28,613	26,443
Supplemental schedule of noncash activities:
Assets acquired under capital lease	111,826	9,086	9,410
Issuance of installment notes associated with equity-based compensation liability awards	5,356	12,433	5,352
Increase (decrease) in insurance claims payable and insurance recoverable	$ 619	$ (2,362)	$ 1,876