Basis Of Presentation (Details)	6 Months Ended
Jun. 30, 2011
Basis Of Presentation
Company's membership interest percentage in joint venture	99.00%
Number of mining complexes operated	24

The number of units or percentage investment held in the subsidiary by the limited liability company or limited partnership.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 22
-Article 12

Name:	us-gaap_SubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipOwnershipInterest
Namespace Prefix:	us-gaap
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration