CREDIT FACILITIES AND LONG-TERM DEBT (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Credit facility and long-term debt
Long-term debt	$ 692		$ 692		$ 742
Less: current portion of long-term debt	3		3		3
Noncurrent portion of long-term debt	689		689		739
Senior Credit Facility due 2016
Credit facility and long-term debt
Stated interest rate (as a percent)	1.61%		1.61%
Long-term debt	313		313		363
Maximum borrowing capacity	500		500
Amount outstanding under credit facility					363
Remaining borrowing capacity	187		187
Line of credit facility, base rate	LIBOR	LIBOR	LIBOR	LIBOR
Debt average interest rate (as a percent)	1.62%	0.90%	1.63%	0.80%
Debt average interest rate, after hedging activity (as a percent)		3.40%		2.70%
Debt interest rate, at period end, prior to hedging activities (as a percent)		1.10%		1.10%
4.65% Senior Notes due 2021
Credit facility and long-term debt
Stated interest rate (as a percent)	4.65%		4.65%		4.65%
Long-term debt	349		349		349
6.89% Series C Senior Notes due 2012
Credit facility and long-term debt
Stated interest rate (as a percent)	6.89%		6.89%		6.89%
Long-term debt	3		3		3
3.82% Series D Senior Notes due 2017
Credit facility and long-term debt
Stated interest rate (as a percent)	3.82%		3.82%		3.82%
Long-term debt	$ 27		$ 27		$ 27