Business Combinations And Other Acquisitions (Acquisition Of Coal Properties) (Narrative) (Details) (USD $)			1 Months Ended	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	May 31, 2012 Daviess And McLean Counties In Kentucky [Member]	Mar. 31, 2013 Daviess And McLean Counties In Kentucky [Member] T	Sep. 30, 2012 Daviess And McLean Counties In Kentucky [Member]	Jun. 30, 2012 Daviess And McLean Counties In Kentucky [Member]
Business Acquisition [Line Items]
Acquisition of mineral rights			$ 1,500,000		$ 1,600,000
Contingent additional payments			3,000,000
Accrued expenses	17,689,000	22,178,000		400,000		2,000,000
Potential payment not recorded as currently not probable						$ 1,000,000
Coal tonnage				32,000,000