Note 10 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Notes Tables

Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]

	December 31,
	2017		2016		2015
Domestic	$	117,273	$	91,597	$	71,323
International		24,552		35,942		18,242
Total	$	141,825	$	127,539	$	89,565

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

	December 31,
	2017			2016		2015
Current:
Federal	$	25,201		$	21,167	$	2,577
International		5,674			10,491		10,076
Total current		30,875			31,658		12,653
Deferred:
Federal	$	7,615		$	8,350	$	22,005
International		(429	)		206		(2,269	)
Total deferred		7,186			8,556		19,736
Total income tax expense	$	38,061		$	40,214	$	32,389

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

	December 31,
	2017			2016			2015
Income tax provision at U.S federal statutory rate	$	49,639		$	44,638		$	31,347
State and local taxes, net of federal income tax benefit		(207	)		(2,310	)		(2,450	)
Effect of foreign income taxed at rates other than the U.S. federal statutory rate		(1,989	)		(1,154	)		989
Foreign income inclusions		-			-			5,017
Tax credits		(100	)		(200	)		(4,685	)
Net change in valuation allowance		(315	)		1,673			3,134
Domestic production deduction		(3,347	)		(2,327	)		(1,958	)
Share-based payment compensation		(5,236	)		-			-
Changes in tax laws		117			-			-
Permanent items and other		(501	)		(106	)		995
Total	$	38,061		$	40,214		$	32,389

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

	December 31,
	2017			2016
Deferred tax assets:
Inventory	$	1,522		$	2,769
Environmental		3,635			5,776
Net operating loss carryforwards		11,447			13,272
Employee benefits		11,245			16,155
Property, plant and equipment		5,007			4,448
Other		3,712			7,352
Total gross deferred tax assets		36,568			49,772
Valuation allowance		(11,824	)		(11,459	)
Total deferred tax assets	$	24,744		$	38,313
Deferred tax liabilities:
Property, plant and equipment		(15,275	)		(17,709	)
Intangibles and other		(8,537	)		(10,583	)
Unremitted foreign earnings		-			(635	)
Foreign tax allocation reserve		(2,710	)		(2,471	)
Other		(2,830	)		(775	)
Total deferred tax liabilities	$	(29,352	)	$	(32,173	)
Net deferred tax assets	$	(4,608	)	$	6,140
Classified as follows in the consolidated balance sheet:
Non-current deferred tax asset		3,198			13,061
Non-current deferred tax liability		(7,806	)		(6,921	)
Total	$	(4,608	)	$	6,140

Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]

	2017			2016			2015
Balance at January 1	$	1,778		$	1,492		$	1,643
Gross increases related to current period tax positions		215			687			281
Gross decreases related to prior period tax positions		(52	)		(84	)		(52	)
Expirations of statute of limitations for the assessment of taxes		(353	)		(257	)		(241	)
Settlements		(134	)		-			-
Foreign currency translation		200			(60	)		(139	)
Balance at December 31	$	1,654		$	1,778		$	1,492