Note 5 - Supplemental Balance Sheet Information (Details Textual) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounts Receivable, Credit Loss Expense (Reversal)	[1]	$ 500	$ (1,930)	$ 8,188
Depreciation, Total		19,300	19,300	21,000
Restructuring 2016 and 2017 [Member]
Accounts Receivable, Credit Loss Expense (Reversal)		$ 500	$ (100)	$ 5,300

[1] The Company recorded bad debt expense (reversals) of $0.5 million, less than ($0.1) million and $5.3 million in 2020, 2019 and 2018, respectively, as part of the restructuring efforts (see Note 4) and was primarily due to the exiting of certain low-return businesses mainly in foreign locations.