CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Apr. 30, 2023	Apr. 30, 2022	Apr. 30, 2021
Preferred Stock [Member]
Statement [Line Items]
Beginning balance, value			$ 2
Beginning balance, shares			1,648
Cumulative-effect adjustment from modified retrospective adoption of ASU 2020-06
Series E preferred stock dividends paid ($2.705 per share)
Conversion of Series E preferred stock to common stock
Conversion of Series E preferred stock to common stock, shares			(28)
Redemption of Series E preferred stock			$ (2)
Redemption of Series E preferred stock, shares			(1,620)
Common stock issued, net of issuance costs of $2,359
Common stock issued under equity compensation plans
Equity component of convertible senior notes
Purchase of capped calls related to convertible senior notes
Stock-based compensation expense
Net income
Ending balance, value
Ending balance, shares
Common Stock [Member]
Statement [Line Items]
Beginning balance, value	$ 62	$ 61	$ 56
Beginning balance, shares	61,807	61,069	56,483
Cumulative-effect adjustment from modified retrospective adoption of ASU 2020-06
Series E preferred stock dividends paid ($2.705 per share)
Conversion of Series E preferred stock to common stock
Conversion of Series E preferred stock to common stock, shares			34
Redemption of Series E preferred stock
Common stock issued, net of issuance costs of $2,359			$ 4
Common stock issued, net of issuance costs of $2,359, shares			3,833
Common stock issued under equity compensation plans	$ 1	$ 1	$ 1
Common stock issued under equity compensation plans, shares	885	738	719
Equity component of convertible senior notes
Purchase of capped calls related to convertible senior notes
Stock-based compensation expense
Net income
Ending balance, value	$ 63	$ 62	$ 61
Ending balance, shares	62,692	61,807	61,069
Additional Paid-in Capital [Member]
Statement [Line Items]
Beginning balance, value	$ 605,841	$ 637,534	$ 612,909
Cumulative-effect adjustment from modified retrospective adoption of ASU 2020-06		(42,431)
Series E preferred stock dividends paid ($2.705 per share)			$ (4,455)
Conversion of Series E preferred stock to common stock
Redemption of Series E preferred stock			$ (40,488)
Common stock issued, net of issuance costs of $2,359			32,137
Common stock issued under equity compensation plans	3,405	3,358	3,983
Equity component of convertible senior notes			42,431
Purchase of capped calls related to convertible senior notes			(12,837)
Stock-based compensation expense	10,978	7,380	3,854
Net income
Ending balance, value	620,224	605,841	637,534
Retained Earnings [Member]
Statement [Line Items]
Beginning balance, value	(431,377)	(559,859)	(571,071)
Cumulative-effect adjustment from modified retrospective adoption of ASU 2020-06		810
Series E preferred stock dividends paid ($2.705 per share)
Conversion of Series E preferred stock to common stock
Redemption of Series E preferred stock
Common stock issued, net of issuance costs of $2,359
Common stock issued under equity compensation plans
Equity component of convertible senior notes
Purchase of capped calls related to convertible senior notes
Stock-based compensation expense
Net income	560	127,672	11,212
Ending balance, value	(430,817)	(431,377)	(559,859)
Beginning balance, value	174,526	77,736	41,896
Cumulative-effect adjustment from modified retrospective adoption of ASU 2020-06		(41,621)
Series E preferred stock dividends paid ($2.705 per share)			$ (4,455)
Conversion of Series E preferred stock to common stock
Redemption of Series E preferred stock			$ (40,490)
Common stock issued, net of issuance costs of $2,359			32,141
Common stock issued under equity compensation plans	3,406	3,359	3,984
Equity component of convertible senior notes			42,431
Purchase of capped calls related to convertible senior notes			(12,837)
Stock-based compensation expense	10,978	7,380	3,854
Net income	560	127,672	11,212
Ending balance, value	$ 189,470	$ 174,526	$ 77,736