COMMITMENTS AND CONTINGENCIES (Summary Of Standby Letters Of Credit) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014		Jun. 30, 2014	Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013	Dec. 31, 2012
Standby Letters of Credit
Long term debt	$ 2,006,113	[1]		$ 2,522,413	[1]	$ 2,523,552	[1]
Reclamation/restoration requirements	228,468		225,117	228,234		233,561		222,851	150,072
Standby Letters of Credit [Member]
Standby Letters of Credit
Risk management insurance	32,839
Reclamation/restoration requirements	6,199
Total	53,268
Industrial revenue bonds | Standby Letters of Credit [Member]
Standby Letters of Credit
Long term debt	$ 14,230

[1] This note matures in 2021, has a stated interest rate of 8.85% and an effective interest rate of 8.88%.