Note 3 - Inventories (Details) (U.S. Barite Ore [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2013
U.S. Barite Ore [Member]
Note 3 - Inventories (Details) [Line Items]
Increase (Decrease) in Raw Materials, Packaging Materials and Supplies Inventories	$ 20.8

The increase (decrease) during the reporting period in the value of raw materials, packaging materials and supplies held in inventory.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Name:	us-gaap_IncreaseDecreaseInRawMaterialsPackagingMaterialsAndSuppliesInventories
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration