Note 11 - Stock Plans - Schedule of Treasury Stock Transactions (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Treasury shares at the beginning of period (in shares)	6,008	5,368	6,020	5,368
Balance	$ 52,465		$ 53,140	$ 58,842
Treasury shares purchased (in shares)	0	652	0	652
Treasury shares reissued (in shares)	(47)	0	(59)	0
Reissuance of treasury stock	$ 0		$ 0
Treasury shares at the end of period (in shares)	5,961	6,020	5,961	6,020
Balance	$ 53,777	$ 52,601	$ 53,777	$ 52,601
Treasury Stock, Common [Member]
Balance	(82,321)	(76,794)	(82,423)	(76,794)
Treasury shares purchased	0	(5,629)	0	(5,629)
Reissuance of treasury stock	394	0	496	0
Balance	$ (81,927)	$ (82,423)	$ (81,927)	$ (82,423)