Note 4 - Restructuring (Details Textual) $ in Thousands	3 Months Ended				6 Months Ended				12 Months Ended	23 Months Ended
	Jun. 30, 2019 USD ($)		Jun. 30, 2018 USD ($)		Jun. 30, 2019 USD ($)		Jun. 30, 2018 USD ($)		Dec. 31, 2017 USD ($)	Jun. 30, 2019 USD ($)
Restructuring Charges, Total	$ 3,000		$ 1,500		$ 4,100		$ 3,300
Restructuring Charges, Non-Cash					1,409		2,980
Restructuring 2017 [Member]
Restructuring Charges Pre Tax										$ 149,000
Restructuring Charges, Net of Tax										135,900
Payments for Restructuring					$ 5,942	[1]	6,481	[2]		34,300
Restructuring Reserve, Settled without Cash										114,700
Goodwill and Intangible Asset Impairment, Total									$ 86,400
Accounts Receivable, Allowance for Credit Loss, Writeoff										$ 28,400
Restructuring and Related Cost, Expected Number of Positions Eliminated										480
Restructuring and Related Cost, Expected Number of Additional Positions Eliminated					30
Restructuring Charges, Total	6,516	[3]	2,913	[4]	$ 9,382	[5]	8,157	[6]
Restructuring Charges, Cash	5,400		2,300		8,500		5,200
Restructuring Charges, Non-Cash	1,100		$ 600		900		$ 2,980
Restructuring 2017 [Member] | Minimum [Member]
Restructuring and Related Cost, Expected Cost, Total	5,000				5,000					$ 5,000
Restructuring 2017 [Member] | Maximum [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 six months of 2019.

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

[3] Total pre-tax restructuring charges for the quarter ended June 30, 2019, include cash charges of $5.4 million and non-cash charges of $1.1 million. Cash charges consist of charges incurred during the quarter that will be settled in cash, either during the current period or future periods.

[4] Total pre-tax restructuring charges for the quarter ended June 30, 2018, include cash charges of $2.3 million and non-cash charges of $0.6 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 $8.5 million and non-cash charges of $0.9 million. Cash charges consist of charges incurred during the quarter that will be settled in cash, either during the current period or future periods.

[6] Total pre-tax restructuring charges include cash charges of $5.2 million and non-cash charges of $3.0 million. Cash charges consist of charges incurred during the quarter that will be settled in cash, either during the current period or future periods.