Note 4 - Restructuring (Details Textual) $ in Thousands	3 Months Ended				9 Months Ended				12 Months Ended	26 Months Ended
	Sep. 30, 2019 USD ($)		Sep. 30, 2018 USD ($)		Sep. 30, 2019 USD ($)		Sep. 30, 2018 USD ($)		Dec. 31, 2017 USD ($)	Sep. 30, 2019 USD ($)
Restructuring Charges, Total	$ 1,400		$ 1,200		$ 5,500		$ 4,500
Restructuring Charges, Non-Cash					6,419		5,891
Restructuring 2017 [Member]
Restructuring Charges Pre Tax										$ 157,600
Restructuring Charges, Net of Tax										140,900
Payments for Restructuring					$ 9,739	[1]	9,424	[2]		37,300
Restructuring Reserve, Settled without Cash										120,300
Goodwill and Intangible Asset Impairment, Total									$ 86,400
Accounts Receivable, Allowance for Credit Loss, Writeoff										$ 33,900
Restructuring and Related Cost, Expected Number of Positions Eliminated										500
Restructuring and Related Cost, Expected Number of Additional Positions Eliminated					30
Restructuring Charges, Total	8,607	[3]	7,423	[4]	$ 17,989	[5]	15,580	[6]
Restructuring Charges, Cash	3,100		2,300		11,600		7,400
Restructuring Charges, Non-Cash	5,500		$ 5,100		6,419		$ 8,150
Restructuring 2017 [Member] | Minimum [Member]
Restructuring and Related Cost, Expected Cost, Total	$ 5,000				$ 5,000					$ 5,000

[1] Refers to cash utilized to settle charges during the first nine months of 2019.

[2] Refers to cash utilized to settle charges during the first nine months of 2018.

[3] Total pre-tax restructuring charges for the quarter ended September 30, 2019, include cash charges of $3.1 million and non-cash charges of $5.5 million. Cash charges consist of charges incurred during the quarter that will be settled in cash, either during the current period or future periods.

[4] Total pre-tax restructuring charges for the quarter ended September 30, 2018, include cash charges of $2.3 million and non-cash charges of $5.1 million. Cash charges consist of charges incurred during the quarter that will be settled in cash, either during the current period or future periods.

[5] Total pre-tax restructuring charges include cash charges of $11.6 million and non-cash charges of $6.4 million. Cash charges consist of charges incurred during the period that will be settled in cash, either during the current period or future periods.

[6] Total pre-tax restructuring charges include cash charges of $7.4 million and non-cash charges of $8.2 million. Cash charges consist of charges incurred during the period that will be settled in cash, either during the current period or future periods.