Note 13 - Segment and Geographical Information (Details) - Segment Information - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
2013
Revenues		$ 819,567	$ 775,615	$ 616,016
Segment profit	[1]	140,745	132,140	97,461
Depreciation and amortization expense		55,691	60,280	62,748
Capital expenditures		(11,190)	(10,894)	(6,544)
Total assets	[2]	1,051,681	930,144	732,513
Long-lived assets	[2],[3]	678,321	662,334	512,579
UNITED STATES
2013
Revenues		511,324	468,419	374,817
Segment profit	[1]	82,751	76,065	46,934
Depreciation and amortization expense		36,101	34,302	31,787
Capital expenditures		(7,171)	(7,687)	(3,197)
Total assets	[2]	637,469	577,974	396,635
Long-lived assets	[2],[3]	467,664	473,800	315,748
CANADA
2013
Revenues		37,473	32,889	31,131
Segment profit	[1]	5,413	4,673	5,137
Depreciation and amortization expense		853	2,824	9,518
Capital expenditures		(248)	(37)	(19)
Total assets	[2]	26,970	25,807	30,061
Long-lived assets	[2],[3]	16,063	18,178	23,056
UNITED KINGDOM
2013
Revenues		190,204	189,755	143,418
Segment profit	[1]	34,786	32,921	29,439
Depreciation and amortization expense		9,270	12,048	11,566
Capital expenditures		(1,380)	(1,254)	(1,781)
Total assets	[2]	304,917	239,260	221,681
Long-lived assets	[2],[3]	134,464	96,635	100,796
AUSTRALIA
2013
Revenues		80,566	84,552	66,650
Segment profit	[1]	17,795	18,481	15,951
Depreciation and amortization expense		9,467	11,106	9,877
Capital expenditures		(2,390)	(1,916)	(1,547)
Total assets	[2]	82,325	87,103	84,136
Long-lived assets	[2],[3]	$ 60,130	$ 73,721	$ 72,979

[1] For segment purposes, the Company defines "segment profit" as earnings before interest expenses, income taxes, depreciation and amortization, share-based compensation expenses, acquisition-related transaction costs and other expenses. A consolidated reconciliation from segment profit to income from operations is included below.

[2] Total assets and long-lived assets include goodwill. 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.

[3] Long-lived assets are noncurrent assets excluding deferred tax assets and deferred financing costs.