CREDIT FACILITIES AND LONG-TERM DEBT (Details) (USD $) In Millions, unless otherwise specified					3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Senior Credit Facility due 2017	Dec. 31, 2012 Senior Credit Facility due 2017	Mar. 31, 2013 Senior Credit Facility due 2017 LIBOR-based borrowings	Mar. 31, 2012 Senior Credit Facility due 2017 LIBOR-based borrowings	Mar. 31, 2013 Senior revolving credit facility	Dec. 31, 2012 Senior revolving credit facility	Mar. 31, 2013 4.65% Senior Notes due 2021	Dec. 31, 2012 4.65% Senior Notes due 2021	Mar. 31, 2013 3.82% Series D Senior Notes due 2017	Dec. 31, 2012 3.82% Series D Senior Notes due 2017
Credit facility and long-term debt
Stated interest rate (as a percent)									4.65%	4.65%	3.82%	3.82%
Total long-term debt	$ 685	$ 688	$ 309	$ 312					$ 349	$ 349	$ 27	$ 27
Less: current portion of long-term debt	3	3
Long-term debt	682	685
Maximum borrowing capacity							500
Amount outstanding under credit facility							309	312
Remaining borrowing capacity							$ 191
Line of credit facility, base rate					LIBOR	LIBOR
Debt average interest rate (as a percent)					1.46%	1.65%
Debt interest rate at end of period (as a percent)					1.46%	1.63%