Note 3 - Valuation and Qualifying Accounts (Tables)

12 Months Ended

Mar. 31, 2022

Notes Tables

Valuation and Qualifying Accounts [Table Text Block]

	Year Ended March 31,
	2022			2021			2020
Allowance for doubtful accounts:
Balance at beginning of period	$	39		$	59		$	39
Provision for doubtful accounts		165			130			191
Write-off of uncollectible accounts receivable		(165	)		(150	)		(171	)
Balance at end of year	$	39		$	39		$	59