Note 5 - Goodwill and Intangible Assets (Details) - Goodwill $ in Thousands	9 Months Ended
	Sep. 30, 2015 USD ($)	[1]
Goodwill [Line Items]
Goodwill balance	$ 495,679
Goodwill acquired during the year	5,208
Adjustments to prior year acquisitions	470
Effect of foreign currency translation	(11,825)
Goodwill balance	489,532
UNITED STATES
Goodwill [Line Items]
Goodwill balance	401,560
Goodwill acquired during the year	5,063
Adjustments to prior year acquisitions	$ 470
Effect of foreign currency translation
Goodwill balance	$ 407,093
CANADA
Goodwill [Line Items]
Goodwill balance	17,178
Goodwill acquired during the year	$ 145
Adjustments to prior year acquisitions
Effect of foreign currency translation	$ (3,143)
Goodwill balance	14,180
UNITED KINGDOM
Goodwill [Line Items]
Goodwill balance	$ 38,354
Goodwill acquired during the year
Adjustments to prior year acquisitions
Effect of foreign currency translation	$ (982)
Goodwill balance	37,372
AUSTRALIA
Goodwill [Line Items]
Goodwill balance	$ 38,587
Goodwill acquired during the year
Adjustments to prior year acquisitions
Effect of foreign currency translation	$ (7,700)
Goodwill balance	$ 30,887

[1] Goodwill recorded in connection with certain tax benefits to be realized in the Company's U.S. income tax returns has been reflected in the United States segment.