Note 7 - Segment Reporting - Segment Information (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Total adjusted EBITDA		$ 454,115	$ 424,552	$ 317,300
Interest expense		(41,544)	(40,956)	(42,667)
Depreciation and amortization		(60,767)	(47,408)	(51,988)
Non-cash write-down and other adjustments (1)	[1]	(240)	(3,532)	(2,923)
Non-cash share-based compensation expense (2)	[2]	(16,694)	(14,563)	(10,205)
Gain (Loss) on Extinguishment of Debt, Total	[3]	(926)	(1,332)	0
Loss on pension settlement (4)	[4]	(10,920)	0	0
Transaction costs and credit facility fees (5)	[5]	(2,724)	(3,883)	(2,145)
Business optimization expenses (6)	[6]	(1,572)	(952)	(2,912)
Other		879	(850)	(761)
Total before tax		319,607	311,076	203,699
Assets		2,665,669	2,426,314	2,025,965
Depreciation and Amortization		60,909	47,408	51,988
Capital expenditures		60,802	47,601	33,261
Domestic [Member]
Total adjusted EBITDA		428,667	388,495	282,450
Assets		2,123,251	1,868,554	1,612,607
Depreciation and Amortization		46,145	35,586	37,962
Capital expenditures		36,007	38,242	29,258
International [Member]
Total adjusted EBITDA		25,448	36,057	34,850
Assets		542,418	557,760	413,358
Depreciation and Amortization		14,764	11,822	14,026
Capital expenditures		$ 24,795	$ 9,359	$ 4,003

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

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

[3] Represents the non-cash write-off of original issue discount and deferred financing costs due to a voluntary prepayment of Term Loan debt.

[4] Represents pre-tax settlement charges related to the termination of the Company’s domestic pension plan in the fourth quarter of 2019.

[5] 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.

[6] Represents severance and other non-recurring restructuring charges related to the consolidation of certain of our facilities.