Note 8 - Inventories (Details) - Inventories (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Raw materials:
Raw materials	$ 158,679	$ 154,691
Total	199,129	189,680
Drilling fluids [Member]
Raw materials:
Raw materials	157,846	153,901
Mats [Member]
Raw materials:
Raw materials	833	790
Finished goods- mats	932	914
Blended Drilling Fluids Components [Member]
Raw materials:
Blended drilling fluids components	$ 39,518	$ 34,075

Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date of merchandise or goods held by the company that are readily available for sale.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.6(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 330

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SAB TOPIC 5.BB)

-URI http://asc.fasb.org/extlink&oid=27011343&loc=d3e100047-122729

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 6

-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 5

-Section BB

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant