Note 7 - Restricted Stock - Non-vested Restricted Stock (Details) shares in Thousands	12 Months Ended
	Mar. 31, 2021 shares
Non-vested restricted stock outstanding at March 31, 2020 (in shares)	183
Restricted stock granted (in shares)	106
Restricted stock vested (in shares)	(126)
Restricted stock forfeited or expired (in shares)	(3)
Non-vested restricted stock outstanding at March 31, 2021 (in shares)	160
Employee Plan [Member]
Non-vested restricted stock outstanding at March 31, 2020 (in shares)	109
Restricted stock granted (in shares)	68
Restricted stock vested (in shares)	(76)
Restricted stock forfeited or expired (in shares)	(3)
Non-vested restricted stock outstanding at March 31, 2021 (in shares)	98
Director Plan [Member]
Non-vested restricted stock outstanding at March 31, 2020 (in shares)	74
Restricted stock granted (in shares)	38
Restricted stock vested (in shares)	(50)
Restricted stock forfeited or expired (in shares)	0
Non-vested restricted stock outstanding at March 31, 2021 (in shares)	62