The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 159

-Paragraph 18

-Subparagraph f

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 18

-Paragraph 20

-Subparagraph a (1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Acquisitions and Divestitures (Details Textual) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended		3 Months Ended				3 Months Ended
	Apr. 30, 2012	Apr. 30, 2012 Common Stock [Member]	Mar. 31, 2012 Cordillera Energy Partners [Member] acre	Jan. 31, 2012 Cordillera Energy Partners [Member]	Mar. 31, 2012 Burrup Holdings Limited [Member]	Jan. 31, 2012 Burrup Holdings Limited [Member]	Mar. 31, 2012 Yara International [Member]
Business Acquisition [Line Items]
Business combination land acquired in acres			312,000
Raising net proceeds, common stock	6,272,667	6,272,667
Cash consideration			$ 2,500	$ 200
Percentage of ownership					49.00%
Ownership percentage by other party							51.00%
Amount paid for acquisition						$ 439