Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time, classified as current.

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Aggregate net gain (loss) on all derivative instruments recognized in earnings during the period, before tax effects.

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Note 1 - Summary of Significant Interim Accounting Policies (Details Textual) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($) shares	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) shares	Jun. 30, 2017 USD ($)	Mar. 31, 2018 USD ($)	Mar. 01, 2018 USD ($)	Jan. 01, 2018 USD ($)	Dec. 31, 2017 USD ($)	Jan. 03, 2017 USD ($)	Jul. 01, 2014 USD ($)
Subsidiary of Limited Liability Company or Limited Partnership, Ownership Interest			99.00%
Amortization of Intangible Assets, Total	$ 1,100	$ 600	$ 1,800	$ 1,100
Advertising Expense	200	100	200	100
Selling, General and Administrative Expense, Total	$ 23,327	16,994	$ 44,509	34,423
Derivative, Notional Amount										$ 14,300
Number of Reportable Segments			3
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant \| shares	3,497,119		3,497,119
Revenue from Contract with Customer, Excluding Assessed Tax, Total	$ 82,392	65,604	$ 155,479	126,591
Revenue, Remaining Performance Obligation, Amount	0		0
Contract with Customer, Asset, Net, Current, Total	46,826		46,826		$ 46,800		$ 43,300
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Revenue from Contract with Customer, Excluding Assessed Tax, Total	(2,939)		790
Accounting Standards Update 2014-09 [Member]
Selling, General and Administrative Expense, Total			706
Revenue from Contract with Customer, Excluding Assessed Tax, Total			$ 42,880
Cumulative Tax Adjustments Payment, Period			4 years
Accounting Standards Update 2014-09 [Member] \| Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Selling, General and Administrative Expense, Total	(90)		$ (22)
Revenue from Contract with Customer, Excluding Assessed Tax, Total	(2,939)		790
Contract with Customer, Asset, Net, Current, Total	46,826		46,826
Accounting Standards Update 2014-09 [Member] \| Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption							$ 11,200
Interest Rate Swap [Member]
Derivative, Notional Amount	18,000		18,000			$ 18,000
Foreign Exchange Contract [Member]
Derivative, Notional Amount									$ 1,800
Foreign Exchange Contract [Member] \| Selling, General and Administrative Expenses [Member]
Gain (Loss) on Derivative Instruments, Net, Pretax, Total		100		(100)
Shipping and Handling [Member]
Selling, General and Administrative Expense, Total	$ 3,300	$ 2,700	$ 6,000	$ 5,400