Note 5 - Goodwill and Intangible Assets (Details) - Goodwill $ in Thousands		6 Months Ended
		Jun. 30, 2015 USD ($)
Goodwill [Line Items]
Goodwill balance	[1]	$ 495,679
Goodwill acquired during the year	[1]	4,654
Adjustments to prior year acquisitions	[1]	471
Effect of foreign currency translation	[1]	(4,322)
Goodwill balance	[1]	496,482
UNITED STATES
Goodwill [Line Items]
Goodwill balance	[1]	401,560
Goodwill acquired during the year	[1]	4,654
Adjustments to prior year acquisitions	[1]	$ 471
Effect of foreign currency translation	[1]
Goodwill balance	[1]	$ 406,685
CANADA
Goodwill [Line Items]
Goodwill balance	[1]	$ 17,178
Goodwill acquired during the year	[1]
Adjustments to prior year acquisitions	[1]
Effect of foreign currency translation	[1]	$ (1,551)
Goodwill balance	[1]	15,627
UNITED KINGDOM
Goodwill [Line Items]
Goodwill balance	[1]	$ 38,354
Goodwill acquired during the year	[1]
Adjustments to prior year acquisitions	[1]
Effect of foreign currency translation	[1]	$ 495
Goodwill balance	[1]	38,849
AUSTRALIA
Goodwill [Line Items]
Goodwill balance	[1]	$ 38,587
Goodwill acquired during the year	[1]
Adjustments to prior year acquisitions	[1]
Effect of foreign currency translation	[1]	$ (3,266)
Goodwill balance	[1]	$ 35,321

[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.