Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2021
Cash flows from operating activities:
Net income	$ 59,648	$ 35,874	$ 19,352
Adjustments to reconcile net income to cash provided by operating activities, net of the effects of acquisitions:
Depreciation and amortization	85,918	95,784	105,828
Loss on extinguishment of debt	0	596	0
Operating lease right-of-use assets	10,598	10,292	10,004
Loss on disposal of fixed assets	49	5	236
Share-based compensation expense associated with equity awards	61,986	56,074	51,892
Change in fair value of derivative instrument	1,380	0	0
Net change in fair value of contingent and contractual liabilities	0	(837)	0
Deferred income taxes	(54,032)	(12,681)	(23,804)
Other gains	(1)	(11)	(196)
Changes in assets and liabilities
Accounts receivable and unbilled costs	4,897	49,322	16,878
Inventories	9,007	(7,996)	(2,043)
Prepaid expenses and other assets	5,039	(13,001)	11,483
Accounts payable	(5,549)	4,211	(1,734)
Accrued compensation and other expenses	12,071	2,391	31,955
Operating lease liabilities	(11,927)	(12,060)	(10,307)
Income taxes payable	165	(3,087)	6,684
Deferred revenue	(22,599)	91,137	(2,307)
Net cash provided by operating activities	156,650	296,013	213,921
Cash flows from investing activities:
Purchase of marketable securities	(114,513)	(78,367)	(15,673)
Proceeds from maturity of marketable securities	140,462	20,569	56,806
Purchase of fixed assets	(10,487)	(10,350)	(11,986)
Purchase of intangible assets	(161)	(50)	(4,537)
Decrease (increase) in deposits	3	(155)	88
Net cash provided by (used in) investing activities	15,304	(68,353)	24,698
Cash flows from financing activities:
Issuance of common stock under stock plans	2	2	2
Payment of contingent consideration	0	0	(1,748)
Treasury stock repurchases	(150,039)	(35,653)	(3,275)
Tax withholding on restricted stock units	(19,393)	(15,691)	(13,286)
Payment of debt issuance costs	0	(3,660)	0
Repayment of long-term debt	(250,000)	(350,000)	(100,000)
Proceeds from issuance of long-term debt	0	350,000	0
Proceeds from collection of contingent consideration, financing activities	0	837	0
Net cash used in financing activities	(419,430)	(54,165)	(118,307)
Effect of exchange rate changes on cash and cash equivalents	(1,891)	(4,510)	6,627
Net (decrease) increase in cash and cash equivalents	(249,367)	168,985	126,939
Cash and cash equivalents and restricted cash, beginning of year	636,161	467,176	340,237
Cash and cash equivalents and restricted cash, end of year	386,794	636,161	467,176
Supplemental disclosures of cash flow information:
Cash paid for interest	8,063	4,962	7,685
Cash paid for income taxes	55,924	31,702	11,472
Non-cash transactions:
Transfers of inventory to fixed assets	1,371	2,657	1,530
Additions to property, plant and equipment included in accounts payable	56	197	333
Issuance of common stock under employee stock purchase plans	$ 14,353	$ 14,582	$ 14,429