Note 2 - Significant Accounting Policies - Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Accumulated depreciation and amortization	$ (514,929)	$ (453,521)
Total	1,159,595	1,135,805
Land [Member]
Property and equipment, gross	129,805	126,123
Building and Building Improvements [Member]
Property and equipment, gross	$ 404,679	377,070
Building and Building Improvements [Member] \| Minimum [Member]
Property and equipment, estimated life (Year)	10 years
Building and Building Improvements [Member] \| Maximum [Member]
Property and equipment, estimated life (Year)	39 years
Leasehold Improvements [Member]
Property and equipment, gross	$ 26,765	26,925
Leasehold Improvements [Member] \| Minimum [Member]
Property and equipment, estimated life (Year)	2 years
Leasehold Improvements [Member] \| Maximum [Member]
Property and equipment, estimated life (Year)	39 years
Machinery and Equipment [Member]
Property and equipment, gross	$ 65,694	67,558
Machinery and Equipment [Member] \| Minimum [Member]
Property and equipment, estimated life (Year)	5 years
Machinery and Equipment [Member] \| Maximum [Member]
Property and equipment, estimated life (Year)	20 years
Furniture and Fixtures [Member]
Property and equipment, gross	$ 63,475	73,912
Furniture and Fixtures [Member] \| Minimum [Member]
Property and equipment, estimated life (Year)	3 years
Furniture and Fixtures [Member] \| Maximum [Member]
Property and equipment, estimated life (Year)	15 years
Transportation Equipment [Member]
Property and equipment, gross	$ 81,158	73,156
Transportation Equipment [Member] \| Minimum [Member]
Property and equipment, estimated life (Year)	2 years
Transportation Equipment [Member] \| Maximum [Member]
Property and equipment, estimated life (Year)	15 years
Vehicles [Member]
Property and equipment, gross	$ 894,905	832,661
Vehicles [Member] \| Minimum [Member]
Property and equipment, estimated life (Year)	2 years
Vehicles [Member] \| Maximum [Member]
Property and equipment, estimated life (Year)	8 years
Construction in Progress [Member]
Property and equipment, gross	$ 8,043	$ 11,921

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.14)
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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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-Subparagraph (SX 210.5-02(13))
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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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-Section S99
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
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