Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2022	Apr. 30, 2021	Apr. 30, 2020
Cash flows from operating activities:
Income from continuing operations	$ 194,494	$ 243,571	$ 27,653
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	30,073	31,575	31,972
Loss on sale/disposition of assets	625	154	419
Provision for losses/(recoveries) on notes and accounts receivable	689	(739)	(585)
Impairment of long-lived tangible assets	86	0	0
Deferred income taxes	(2,125)	447	(260)
Change in fair value of contingent consideration	0	0	100
Stock-based compensation expense	4,536	4,706	2,357
Changes in operating assets and liabilities:
Accounts receivable	4,058	(5,824)	(198)
Inventories	(58,183)	25,264	(911)
Prepaid expenses and other current assets	2,839	(852)	(3,124)
Income taxes	480	(3,643)	6,196
Accounts payable	(26,957)	25,540	4,043
Accrued payroll and incentives	(10)	4,933	(5,831)
Accrued profit sharing	(902)	12,248	(355)
Accrued expenses and deferred revenue	(9,725)	(24,633)	21,755
Accrued warranty	(361)	(1,098)	(1,126)
Other assets	2,561	1,579	1,131
Other non-current liabilities	(4,364)	4,032	(2,401)
Cash provided by operating activities - continuing operations	137,814	317,260	80,835
Cash (used in)/provided by operating activities - discontinued operations	0	(1,926)	13,901
Net cash provided by operating activities	137,814	315,334	94,736
Cash flows from investing activities:
Refunds on machinery and equipment	0	310	0
Receipts from note receivable	0	0	786
Payments to acquire patents and software	(283)	(632)	(429)
Proceeds from sale of property and equipment	139	113	0
Payments to acquire property and equipment	(23,972)	(22,052)	(12,441)
Cash used by investing activities - continuing operations	(24,116)	(22,261)	(12,084)
Cash used by investing activities - discontinued operations	0	(1,143)	(1,874)
Net cash used in investing activities	(24,116)	(23,404)	(13,958)
Cash flows from financing activities:
Proceeds from loans and notes payable	0	25,000	228,225
Cash paid for debt issuance costs	0	(450)	(875)
Payments on finance lease obligation	(1,087)	(996)	(900)
Payments on notes and loans payable	0	(185,000)	(224,600)
Distribution to discontinued operations	0	(25,000)	0
Payments to acquire treasury stock	(90,000)	(110,000)	0
Dividend distribution	(15,035)	(8,223)	0
Proceeds from exercise of options to acquire common stock, including employee stock purchase plan	1,719	3,154	2,127
Payment of employee withholding tax related to restricted stock units	(1,584)	(2,243)	(597)
Cash (used in)/provided by financing activities - continuing operations	(105,987)	(303,758)	3,380
Cash used in financing activities - discontinued operations	0	(166)	0
Net cash (used in)/provided by financing activities	(105,987)	(303,924)	3,380
Net (decrease)/increase in cash and cash equivalents	7,711	(11,994)	84,158
Cash and cash equivalents, beginning of period	113,017	125,011	40,853
Cash and cash equivalents, end of period	120,728	113,017	125,011
Supplemental disclosure of cash flow information Cash paid for:
Interest	2,219	3,306	11,103
Income taxes	59,183	80,874	6,935
Supplemental Disclosure of Non-cash Investing and Financing Activities:
Purchases of property and equipment included in accounts payable	408	746	436
Machinery and equipment on deposit placed into service	0	1,855	0
ASU 2016-02
Supplemental disclosure of cash flow information Cash paid for:
Changes in other assets for operating lease obligations	0	0	11,821
Change in property and equipment	0	0	3,276
Changes in finance lease liabilities	0	0	(4,245)
Changes in lease liabilities for operating lease obligations	$ 0	$ 0	$ 12,790