Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net income (loss)	$ 19,352	$ (2,754)	$ (73,324)
Adjustments to reconcile net income (loss) to cash provided by operating activities, net of the effects of acquisitions:
Depreciation and amortization	105,828	116,104	137,878
Operating lease right-of-use assets	10,004	10,504
Loss on divestiture of business	0	0	7,660
Loss on disposal of fixed assets	236	16	260
Deal related compensation expense and accretion charges	0	0	102
Share-based compensation expense associated with equity awards	51,892	50,861	56,328
Net change in fair value of contingent and contractual liabilities	0	798	1,614
Accretion of contingent consideration	0	(36)	(119)
Impairment charge	0	0	35,871
Deferred income taxes	(23,804)	(9,821)	(33,442)
Other gains	(196)	(152)	(152)
Changes in assets and liabilities
Accounts receivable and unbilled costs	16,878	21,472	(22,180)
Due from related party	0	0	172
Inventories	(2,043)	1,501	5,321
Prepaid expenses and other assets	11,483	13,839	3,034
Accounts payable	(1,734)	(4,288)	(3,876)
Accrued compensation and other expenses	31,955	32,812	19,964
Operating lease liabilities	(10,307)	(13,077)
Due to related party	0	0	234
Income taxes payable	6,684	(919)	(639)
Deferred revenue	(2,307)	8,163	15,132
Net cash provided by operating activities	213,921	225,023	149,838
Cash flows from investing activities:
Purchase of marketable securities	(15,673)	(117,383)	(229,769)
Proceeds from maturity of marketable securities	56,806	144,322	230,433
Purchase of fixed assets	(11,986)	(19,922)	(23,392)
Purchase of intangible assets	(4,537)	0	0
Payments related to the divestiture of business	0	0	(3,293)
Acquisition of businesses, net of cash acquired	0	(11,347)	0
Decrease (increase) in deposits	88	(31)	(97)
Collection of contingent consideration	0	52	0
Capitalized software development costs	0	0	(134)
Net cash provided by (used in) investing activities	24,698	(4,309)	(26,252)
Cash flows from financing activities:
Issuance of common stock under stock plans	2	2	3
Payment of contingent consideration	(1,748)	0	(2,851)
Treasury stock repurchases	(3,275)	(175,000)	(14,468)
Tax withholding on restricted stock units	(13,286)	(11,872)	(11,969)
Repayment of long-term debt	(100,000)	(100,000)	(50,000)
Net cash used in financing activities	(118,307)	(286,870)	(79,285)
Effect of exchange rate changes on cash and cash equivalents	6,627	(3,427)	(5,212)
Net increase (decrease) in cash and cash equivalents	126,939	(69,583)	39,089
Cash and cash equivalents and restricted cash, beginning of year	340,237	409,820	370,731
Cash and cash equivalents and restricted cash, end of year	467,176	340,237	409,820
Supplemental disclosures of cash flow information:
Cash paid for interest	7,685	17,644	23,281
Cash paid for income taxes	11,472	13,061	13,381
Non-cash transactions:
Transfers of inventory to fixed assets	1,530	2,290	2,152
Additions to property, plant and equipment included in accounts payable	333	255	455
Issuance of common stock under employee stock purchase plans	14,429	14,227	15,074
Contingent consideration related to acquisition, included in accrued other	0	1,800	0
Tenant improvement allowance	0	0	10,171
Initial fair value of contingent consideration received as partial consideration for divestiture of business	$ 0	$ 0	$ 2,257