Note 13 - Segment and Geographical Information (Details) - Segment Information - USD ($) $ in Thousands		3 Months Ended				6 Months Ended
		Jun. 30, 2015		Jun. 30, 2014		Jun. 30, 2015		Jun. 30, 2014		Dec. 31, 2014
Note 13 - Segment and Geographical Information (Details) - Segment Information [Line Items]
Revenues	[1]	$ 208,738		$ 196,445		$ 405,054		$ 369,473
Segment profit	[1]	36,357		34,579		68,309		62,589
Depreciation and amortization expense	[1]	13,729		14,858		28,577		29,200
Capital expenditures	[1]	(2,614)		(2,899)		(4,843)		(3,610)
Six months ended June 30, 2014
Total assets		1,061,185	[1],[2]	949,692	[1],[2]	1,061,185	[1],[2]	949,692	[1],[2]	$ 930,144
Long-lived assets	[1],[2],[3]	652,565		703,751		652,565		703,751
UNITED STATES
Note 13 - Segment and Geographical Information (Details) - Segment Information [Line Items]
Revenues	[1]	132,125		117,343		253,843		223,392
Segment profit	[1]	22,752		20,629		42,274		36,583
Depreciation and amortization expense	[1]	9,071		8,169		18,482		15,888
Capital expenditures	[1]	(1,653)		(2,462)		(3,323)		(2,864)
Six months ended June 30, 2014
Total assets	[1],[2]	699,371		575,153		699,371		575,153
Long-lived assets	[1],[2],[3]	472,161		486,176		472,161		486,176
CANADA
Note 13 - Segment and Geographical Information (Details) - Segment Information [Line Items]
Revenues	[1]	9,672		8,578		17,621		16,085
Segment profit	[1]	1,350		1,165		1,984		2,263
Depreciation and amortization expense	[1]	108		711		690		1,522
Capital expenditures	[1]	(55)		(8)		(169)		(9)
Six months ended June 30, 2014
Total assets	[1],[2]	24,212		28,904		24,212		28,904
Long-lived assets	[1],[2],[3]	16,041		21,411		16,041		21,411
UNITED KINGDOM
Note 13 - Segment and Geographical Information (Details) - Segment Information [Line Items]
Revenues	[1]	46,012		48,665		93,456		90,718
Segment profit	[1]	7,482		8,378		15,182		15,459
Depreciation and amortization expense	[1]	2,097		3,094		4,480		6,269
Capital expenditures	[1]	(245)		(228)		(434)		(517)
Six months ended June 30, 2014
Total assets	[1],[2]	251,876		244,176		251,876		244,176
Long-lived assets	[1],[2],[3]	97,286		107,338		97,286		107,338
AUSTRALIA
Note 13 - Segment and Geographical Information (Details) - Segment Information [Line Items]
Revenues	[1]	20,929		21,859		40,134		39,278
Segment profit	[1]	4,773		4,407		8,869		8,284
Depreciation and amortization expense	[1]	2,453		2,885		4,925		5,521
Capital expenditures	[1]	(661)		(201)		(917)		(220)
Six months ended June 30, 2014
Total assets	[1],[2]	85,726		101,459		85,726		101,459
Long-lived assets	[1],[2],[3]	$ 67,077		$ 88,826		$ 67,077		$ 88,826

[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.