Note 3 - Acquisitions (Details) - Preliminary Allocation of Purchase Price, 2014 - USD ($)		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Note 3 - Acquisitions (Details) - Preliminary Allocation of Purchase Price, 2014 [Line Items]
Goodwill	[1]	$ 508,297,000	$ 495,679,000	$ 369,312,000
2014 Acquisitions [Member]
Note 3 - Acquisitions (Details) - Preliminary Allocation of Purchase Price, 2014 [Line Items]
Equipment and leasehold improvements		886,000
Goodwill		136,504,000
Net deferred tax liability associated with step-up in book basis		(9,041,000)
Assets acquired and liabilities assumed, net		3,406,000
Totals		194,773,000	194,800,000
2014 Acquisitions [Member] | Scenario, Previously Reported [Member]
Note 3 - Acquisitions (Details) - Preliminary Allocation of Purchase Price, 2014 [Line Items]
Equipment and leasehold improvements			886,000
Goodwill			136,034,000
Net deferred tax liability associated with step-up in book basis			(9,041,000)
Assets acquired and liabilities assumed, net			3,785,000
Totals			194,682,000
2014 Acquisitions [Member] | Scenario, Adjustment [Member]
Note 3 - Acquisitions (Details) - Preliminary Allocation of Purchase Price, 2014 [Line Items]
Goodwill			470,000
Assets acquired and liabilities assumed, net			(379,000)
Totals		91,000	91,000
Customer Relationships [Member] | 2014 Acquisitions [Member]
Note 3 - Acquisitions (Details) - Preliminary Allocation of Purchase Price, 2014 [Line Items]
Intangible assets		50,216,000
Customer Relationships [Member] | 2014 Acquisitions [Member] | Scenario, Previously Reported [Member]
Note 3 - Acquisitions (Details) - Preliminary Allocation of Purchase Price, 2014 [Line Items]
Intangible assets			50,216,000
Trade Names [Member] | 2014 Acquisitions [Member]
Note 3 - Acquisitions (Details) - Preliminary Allocation of Purchase Price, 2014 [Line Items]
Intangible assets		10,342,000
Trade Names [Member] | 2014 Acquisitions [Member] | Scenario, Previously Reported [Member]
Note 3 - Acquisitions (Details) - Preliminary Allocation of Purchase Price, 2014 [Line Items]
Intangible assets			10,342,000
Noncompete Agreements [Member] | 2014 Acquisitions [Member]
Note 3 - Acquisitions (Details) - Preliminary Allocation of Purchase Price, 2014 [Line Items]
Intangible assets		590,000
Noncompete Agreements [Member] | 2014 Acquisitions [Member] | Scenario, Previously Reported [Member]
Note 3 - Acquisitions (Details) - Preliminary Allocation of Purchase Price, 2014 [Line Items]
Intangible assets			590,000
Technology-Based Intangible Assets [Member] | 2014 Acquisitions [Member]
Note 3 - Acquisitions (Details) - Preliminary Allocation of Purchase Price, 2014 [Line Items]
Intangible assets		$ 1,870,000
Technology-Based Intangible Assets [Member] | 2014 Acquisitions [Member] | Scenario, Previously Reported [Member]
Note 3 - Acquisitions (Details) - Preliminary Allocation of Purchase Price, 2014 [Line Items]
Intangible assets			$ 1,870,000

[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.