Note 7 - Debt, Credit Facility and Leases - Debt Summary (Details) - Senior Notes [Member] - USD ($) $ in Thousands	Dec. 31, 2021	Mar. 31, 2021
Principal	$ 513,051	$ 513,605
Unamortized discount/premium and issuance costs	(4,956)	(4,753)
Long-term debt balance	508,095	508,852
The 2028 Senior Notes [Member]
Principal	475,000	475,000
Unamortized discount/premium and issuance costs	(5,552)	(5,324)
Long-term debt balance	469,448	469,676
IQ Notes [Member]
Principal	38,051	38,605
Unamortized discount/premium and issuance costs	596	571
Long-term debt balance	$ 38,647	$ 39,176

Amount, excluding unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

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