DEBT (Narrative) (Details) (USD $)	1 Months Ended	9 Months Ended			9 Months Ended			1 Months Ended		9 Months Ended
	Mar. 31, 2014	Sep. 30, 2014	Sep. 30, 2013	Jun. 30, 2011	Sep. 30, 2014 Standby Letters of Credit [Member]	Sep. 30, 2014 Minimum Standby Letters of Credit [Member]	Sep. 30, 2014 Maximum Standby Letters of Credit [Member]	Jun. 30, 2013 Medium-term Notes	Jan. 31, 2013 Medium-term Notes	Sep. 30, 2014 Medium-term Notes	Sep. 30, 2014 6.50% notes due 2016	Sep. 30, 2014 7.50% notes due 2021	Sep. 30, 2014 10.125% notes due 2015	Sep. 30, 2014 10.375% notes due 2018	Sep. 30, 2014 7.00% notes due 2018	Sep. 30, 2014 6.40% notes due 2017	Sep. 30, 2014 7.15% notes due 2037	Sep. 30, 2014 Line of Credit	Sep. 30, 2014 Line of Credit Minimum	Sep. 30, 2014 Line of Credit Maximum
Debt Instrument [Line Items]
Required periodic principal payment		$ 0						$ 140,444,000	$ 10,000,000
Debt instrument face amount				500,000,000
Debt purchased, amount		506,366,000									374,999,000					131,367,000
Maturity year										2021	2016	2021	2015	2018	2018	2017	2037
Interest rate				6.50%				6.30%	8.70%	8.85%	6.50%	7.50%	10.125%	10.375%	7.00%	6.40%	7.15%
Amount of bank credit facility																		500,000,000
Facility expiration date																		Mar. 25, 2019
Commitment fee						0.25%	0.40%
Borrowing capacity		446,732,000
Applicable margin for LIBOR based borrowing					0.175%													1.75%	1.50%	2.25%
Total consideration paid for debt	579,659,000	649,711,000	306,493,000
Premium paid for purchase of debt		71,829,000
Transaction cost related to termination of debt		1,464,000
Other benefit related to debt purchase		344,000
Cost of debt purchase		$ 72,949,000	$ 0
Debt to EBITDA ratio		3.5
EBITDA to net cash interest expense ratio		3.0