Commitments and Contingencies Commitments and Contingencies, Environmental Contingencies (Details)	Jun. 30, 2013 Federal Clean Water Act Regulation	Jul. 31, 2013 New Mexico Greenhouse Gas (GHG) Regulations Regulation
Environmental Requirements [Abstract]
Number of potential regulatory options under the proposed Effluent Limitations Guidelines rule	4
Number of New Mexico GHG emission regulations which were repealed		2