Note 6 - Segment Reporting - Segment Information (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Net sales		$ 331,814	$ 286,535
Total adjusted EBITDA		47,658	49,809
Interest expense		(10,788)	(11,035)
Depreciation and amortization		(12,597)	(12,793)
Non-cash write-down and other adjustments (1)	[1]	(166)	127
Non-cash share-based compensation expense (2)	[2]	(2,632)	(2,485)
Transaction costs and credit facility fees (3)	[3]	(316)	(523)
Business optimization expenses (4)	[4]	(100)	(7,106)
Other		41	(63)
Income before provision for income taxes		21,100	15,931
Domestic [Member]
Net sales		248,497	248,017
Total adjusted EBITDA		42,846	46,860
International [Member]
Net sales		83,317	38,518
Total adjusted EBITDA		$ 4,812	$ 2,949

[1] Includes gains/losses on disposal of assets, unrealized mark-to-market adjustments on commodity contracts, and certain foreign currency and purchase accounting related adjustments.

[2] Represents share-based compensation expense to account for stock options, restricted stock and other stock awards over their respective vesting periods.

[3] Represents transaction costs incurred directly in connection with any investment, as defined in our credit agreement; equity issuance, debt issuance or refinancing; together with certain fees relating to our senior secured credit facilities.

[4] Represents charges relating to business optimization and restructuring costs.