Basis Of Presentation (Narrative) (Details)	3 Months Ended
Mar. 31, 2012
Basis Of Presentation [Abstract]
Number of mining complexes operated	23
Company's membership interest percentage in joint venture	99.00%

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