Summary Financial Information (Consolidated Statements of Cash Flows ) (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Operating activities:
Net cash provided by (used for) operating activities	$ 106,795	$ 79,499	$ 69,661
Investing activities:
Proceeds from sales of marketable securities	5,380	3,266	653
Purchases of marketable securities	(5,747)	(2,604)	(327)
Capital expenditures	(9,432)	(12,288)	(14,515)
Financing activities:
Proceeds from issuance of common stock	6,000	4,152	6,332
Repayment of debt	(51,113)	(65,088)	(60,144)
Fees related to debt repricing/refinancing and equity offerings	0	0	(619)
Other	(768)	(2,190)	(1,413)
Net cash provided by (used for) financing activities	(51,551)	(67,778)	(59,502)
Effect of exchange rate changes on cash	(1,925)	(6,429)	7,569
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 114,700	$ 71,343	$ 63,565	$ 78,429