Note 5 - Goodwill and Other Intangible Assets - Changes in Carrying Amount of Goodwill (Details) - USD ($)		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015
Balance as of January 1		$ 687,404,000	$ 687,778,000
Effect of foreign currency translation		(4,833,000)	(3,375,000)
Balance as of December 31		683,683,000	687,404,000
Trade NTE [Member]
Goodwill resulting from business combinations		191,000
Mostra [Member]
Goodwill resulting from business combinations	[1],[2]	654,000
Goodwill, Purchase Accounting Adjustments	[1],[2]		(380,000)
City Tech [Member]
Goodwill resulting from business combinations	[1]
Goodwill, Purchase Accounting Adjustments	[1]		(29)
Olson [Member]
Goodwill resulting from business combinations	[1],[2]	$ 267,000	3,410,000
Goodwill, Purchase Accounting Adjustments			$ 3,400,000

[1] During the year ended December 31, 2015, the Company recorded changes to goodwill representing adjustments during the measurement-period (up to one year from the date of an acquisition) as well as new information related to acquisitions during the year ended December 31, 2014. These goodwill adjustments were not significant to our previously reported operating results or financial position. See further discussion of the Company's business combinations in "Note 6-Business Combinations."

[2] During the year ended December 31, 2016, the Company recorded changes to goodwill representing adjustments for deferred tax balances relating to acquired assets and liabilities. These balances were not significant to our previously reported operating results or financial position.