LONG-TERM DEBT AND LEASE OBLIGATIONS (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended				3 Months Ended										3 Months Ended
	Mar. 31, 2014	Mar. 31, 2014 9 1/4%, due 2015	Dec. 31, 2013 9 1/4%, due 2015	Mar. 31, 2014 Credit Agreement	Mar. 31, 2014 Credit Agreement Low end of range	Mar. 31, 2014 Credit Agreement High end of range	Mar. 31, 2014 Credit Agreement Base rate	Mar. 31, 2014 Credit Agreement Base rate Low end of range	Mar. 31, 2014 Credit Agreement Base rate High end of range	Mar. 31, 2014 Credit Agreement LIBOR	Mar. 31, 2014 Credit Agreement LIBOR Low end of range	Mar. 31, 2014 Credit Agreement LIBOR High end of range	Mar. 31, 2014 Letter of Credit Facility	Mar. 07, 2014 Letter of Credit Facility	Mar. 31, 2014 Letter of Credit Facility High end of range
LONG-TERM DEBT AND LEASE OBLIGATIONS
Revolving credit facility, maximum borrowing capacity				$ 1,000										$ 180
Line of credit facility, subfacility maximum available capacity				300
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
Interest rate, stated percentage		9.25%	9.25%
Carrying amount		474	474
Base rate used to calculate interest rate							base rate			LIBOR			base
Margin on variable rate (as a percent)								1.00%	1.50%		2.00%	2.50%	0.88%
Unused commitment fee (as a percent)					0.375%	0.50%							0.50%
Outstanding cash borrowings				170									180
Interest rate on borrowings (as a percent)	1.875%			2.62%
Standby letters of credit outstanding				5
Amount available for borrowing under revolving credit facility				825
Borrowing capacity after increase subject to certain conditions														$ 200
Number of business days after notice, for reimbursement of amount drawn.															3 days
Unused commitment fee after step down															0.375%
Secured debt to EBITDA ratio	3.00
Issuance fee (percentage)	0.125%