Note 5 - Income Taxes (Tables)

12 Months Ended

Mar. 31, 2018

Notes Tables

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

	March 31,
	2018			2017
Deferred tax assets:
Accrued expenses	$	346		$	474
Deferred stock compensation		353			334
Bad debt and inventory reserves		22			29
Total deferred tax assets		721			837
Deferred tax liabilities:
Property and equipment		1,717			1,925
Total net deferred taxes	$	(996	)	$	(1,088	)

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

	Year Ended March 31,
	2018			2017		2016
Current taxes
Federal	$	15,012		$	11,095	$	10,982
State		1,586			1,059		1,041
Total current taxes		16,598			12,154		12,023
Deferred taxes
Federal		(83	)		1,781		(21	)
State		(9	)		170		(2	)
Total deferred taxes		(92	)		1,951		(23	)
Total provision for income taxes	$	16,506		$	14,105	$	12,000

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

	Year Ended March 31,
	2018			2017			2016
Income taxes at U.S. statutory rates	$	16,943		$	13,274		$	11,399
State income taxes, net of federal tax benefit		1,078			858			675
Restricted stock windfall adjustment		(1,086	)
Reduction of deferred tax liability due to rate reduction					(430	)
Permanent differences		1			1			(23	)
Other		-			(28	)		(51	)
Total provision for income taxes	$	16,506		$	14,105		$	12,000