CASH DISTRIBUTIONS (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
CASH DISTRIBUTIONS
Quarterly cash distributions (in dollars per unit)	$ 0.78	$ 0.77	$ 2.32	$ 2.27
Cash distribution	$ 43	$ 42	$ 127	$ 113