Note 16 - Income Tax (Benefit) Provision (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

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

	2019			2018			2017
Income before taxes - U.S.	$	79,795		$	60,177		$	16,649
Income tax provision:
Federal
Current		(2,811	)		7,105			6,185
Deferred		(4,006	)		(1,389	)		(12,632	)
State and other
Current		(430	)		1,167			610
Deferred		(1,139	)		136			(1,025	)
Total	$	(8,386	)	$	7,019		$	(6,862	)

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

	2019		2018		2017
Amount computed using the statutory rate	21.0%		21.0%		35.0%
Section 199 manufacturing deduction	-		-		(0.5%	)
Small Agri-biodiesel Producer Tax Credit	(3.0%	)	(1.6%	)	-
Federal BTC benefit	(23.4%	)	(12.9%	)	-
State BTC benefit	(5.8%	)	(3.3%	)	-
Credit for increasing research activities	(0.2%	)	(0.2%	)	(0.8%	)
Dividends received deduction	(0.4%	)	(0.6%	)	(5.2%	)
State income taxes, net	4.0%		4.2%		2.8%
State research credits	(0.9%	)	-		-
State rate change impact	(1.6%	)	-		-
Tax expense recorded as an increase in unrecognized tax benefit	-		5.3%		1.1%
Tax Cuts and Jobs Act of 2017 impact	-		-		(72.5%	)
Other	(0.2%	)	(0.2%	)	(1.1%	)
Income tax (benefit) provision	(10.5%	)	11.7%		(41.2%	)

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

	2019			2018
Deferred tax assets
Compensation	$	267		$	30
Inventory reserves		650			458
Self-insurance		103			63
Asset retirement obligation		199			209
Deferred revenue		4,427			5,015
Federal net operating loss carryforwards		3,121			1
State net operating loss carryforwards		363			-
Accrued expenses		1,684			1,653
Stock-based compensation		41			108
State credit carryforwards		343			-
Derivative instruments		56			-
Other		-			130
Total deferred tax assets		11,254			7,667
Deferred tax liabilities
Available-for-sale securities, unrealized gains		(79	)		-
Derivative instruments		-			(86	)
LIFO inventory		(2,860	)		(3,389	)
Depreciation		(19,891	)		(22,010	)
Marketable securities, unrealized gains		(1,334	)		-
Other		(55	)		(208	)
Total deferred tax liabilities		(24,219	)		(25,693	)
Net deferred tax liabilities	$	(12,965	)	$	(18,026	)

Summary of Income Tax Contingencies [Table Text Block]

	2019			2018		2017
Balance at January 1	$	2,804		$	-	$	2,056
Increases to tax positions taken in the current year		-			-		-
Increases to tax positions taken in a prior year		-			2,804		-
Decrease due to resolution of tax positions taken in a prior year		(2,804	)		-		(2,056	)
Balance at December 31	$	-		$	2,804	$	-