CREDIT FACILITIES AND LONG-TERM DEBT (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Credit facility and long-term debt
Long-term debt	$ 700		$ 700		$ 742
Less: current portion of long-term debt	3		3		3
Noncurrent portion of long-term debt	697		697		739
Senior Credit Facility due 2016
Credit facility and long-term debt
Long-term debt	321		321		363
Maximum borrowing capacity	500		500
Remaining borrowing capacity	179		179
Line of credit facility, base rate	LIBOR	LIBOR	LIBOR	LIBOR
Debt interest rate (as a percent)	1.63%		1.63%
Debt average interest rate (as a percent)	1.62%	0.90%	1.64%	0.90%
Debt average interest rate, after hedging activity (as a percent)		3.50%		3.70%
Debt interest rate, at period end, prior to hedging activities (as a percent)		0.60%		0.60%
4.65% Senior Notes due 2021
Credit facility and long-term debt
Long-term debt	349		349		349
Debt interest rate (as a percent)			4.65%
6.89% Series C Senior Notes due 2012
Credit facility and long-term debt
Long-term debt	3		3		3
Debt interest rate (as a percent)	6.89%		6.89%
3.82% Series D Senior Notes due 2017
Credit facility and long-term debt
Long-term debt	$ 27		$ 27		$ 27
Debt interest rate (as a percent)	3.82%		3.82%