Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended			6 Months Ended		12 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Mar. 31, 2024
Cash flows from operating activities:
Net income (loss)	$ 9,027		$ 21,462	$ (434,349)	$ 17,262
Adjustments to reconcile net income (loss) to cash provided by (used in) operating activities:
Depreciation and amortization				32,505	38,410
Operating lease right-of-use asset amortization				5,227	5,218
Gain on divestiture of a business	0		(3,806)	0	(3,806)
Loss on disposal of fixed assets				15	45
Share-based compensation expense				36,084	38,289
Change in fair value of derivative investment				0	(206)
Goodwill impairment	0	$ 427,000	0	426,967	0		$ 217,300
Deferred income taxes				(24,819)	(21,411)
Other gains				(7,633)	(82)
Changes in assets and liabilities
Accounts receivable and unbilled costs				73,697	(8,952)
Inventories and deferred costs				(3,213)	(1,211)
Prepaid expenses and other assets				(4,697)	(7,666)
Accounts payable				(516)	(1,109)
Accrued compensation and other expenses				(6,264)	(49,851)
Operating lease liabilities				(5,915)	(5,908)
Income taxes payable				194	(2,948)
Deferred revenue				(52,584)	(44,805)
Net cash provided by (used in) operating activities				34,699	(48,731)
Cash flows from investing activities:
Purchase of marketable securities and investments				(20,999)	(41,920)
Proceeds from sales and maturity of marketable securities				25,290	30,162
Purchase of fixed assets				(2,150)	(3,498)
Purchase of intangible assets				(1,290)	0
Proceeds from divestiture of a business				0	8,283
Net cash provided by (used in) investing activities				851	(6,973)
Cash flows from financing activities:
Issuance of common stock under stock plans				2	2
Treasury stock repurchases				(25,257)	(31,137)
Tax withholding on restricted stock units				(13,499)	(18,718)
Repayment of long-term debt				(25,000)	0
Net cash used in financing activities				(63,754)	(49,853)
Effect of exchange rate changes on cash and cash equivalents				1,885	(1,293)
Net decrease in cash and cash equivalents				(26,319)	(106,850)
Cash and cash equivalents, beginning of period		$ 389,674		389,674	386,794	$ 279,944	386,794
Cash and cash equivalents, end of period	$ 363,355		$ 279,944	363,355	279,944	$ 363,355	$ 389,674
Supplemental disclosures:
Cash paid for interest				2,693	3,192
Cash paid for income taxes				22,176	41,250
Non-cash transactions:
Transfers of inventory to fixed assets				1,020	1,814
Additions to property, plant and equipment included in accounts payable				86	400
Issuance of common stock under employee stock plans				4,577	6,006
Unsettled share repurchases, included in accounts payable				$ 0	$ 43