LONG-TERM DEBT AND LEASE OBLIGATIONS (Details 2) (USD $)				9 Months Ended
	Sep. 30, 2013 9.25% senior notes due 2015	Dec. 31, 2012 9.25% senior notes due 2015	Sep. 30, 2013 Credit Agreement	Sep. 30, 2013 Credit Agreement Initial six months period	Sep. 30, 2013 Credit Agreement Period after six months Low end of range	Sep. 30, 2013 Credit Agreement Period after six months High end of range	Sep. 30, 2013 Credit Agreement Base rate Initial six months period	Sep. 30, 2013 Credit Agreement Base rate Period after six months	Sep. 30, 2013 Credit Agreement Base rate Period after six months Low end of range	Sep. 30, 2013 Credit Agreement Base rate Period after six months High end of range	Sep. 30, 2013 Credit Agreement LIBOR Initial six months period	Sep. 30, 2013 Credit Agreement LIBOR Period after six months	Sep. 30, 2013 Credit Agreement LIBOR Period after six months Low end of range	Sep. 30, 2013 Credit Agreement LIBOR Period after six months High end of range
LONG-TERM DEBT AND LEASE OBLIGATIONS
Revolving credit facility, maximum borrowing capacity			$ 800,000,000
Revolving credit facility, maximum borrowing capacity after increase subject to certain conditions			1,000,000,000
Line of credit facility, subfacility maximum available capacity			300,000,000
Outstanding principal amount of notes that must be repaid or refinanced on or before November 3, 2014 to extend the maturity date of the credit facility		238,000,000
Base rate used to calculate interest rate							base rate	base rate			LIBOR	LIBOR
Margin on variable rate (as a percent)							1.25%		1.00%	1.50%	2.25%		2.00%	2.50%
Unused commitment fee (as a percent)				0.438%	0.375%	0.50%
Interest rate, stated percentage	9.25%	9.25%
Outstanding cash borrowings			210,000,000
Interest rate on borrowings (as a percent)			2.39%
Standby letters of credit outstanding			152,000,000
Amount available for borrowing under revolving credit facility			$ 415,000,000