Note 13 - Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accrued expenses	$ 22,758	$ 18,982
Deferred revenue	10,645	9,389
Inventories	10,159	9,772
Pension obligations	7,512	7,684
Stock-based compensation	7,291	7,974
Operating loss and credit carryforwards	20,927	15,677
Other	2,822	2,842
Valuation allowance	(4,362)	(1,523)
Total deferred tax assets	77,752	70,797
Goodwill and intangible assets	58,133	12,455
Depreciation	25,194	19,507
Debt refinancing costs	7,193	7,732
Prepaid expenses	1,173	1,241
Total deferred tax liabilities	91,693	40,935
Net deferred tax assets (liabilities)	$ (13,941)
Net deferred tax assets (liabilities)		$ 29,862