EMPLOYEE BENEFIT PLANS - NET PENSION EXPENSE (DETAILS) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Qualified Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	$ 12	$ 9	$ 23	$ 19
Interest cost	18	18	36	37
Expected return on assets	(28)	(23)	(55)	(47)
Amortization of prior service cost	0	0	0	(1)
Recognized actuarial loss	11	10	21	20
Net pension expense	13	14	25	28
Nonqualified Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	1	0	1	0
Interest cost	0	1	1	1
Expected return on assets	0	0	0	0
Amortization of prior service cost	0	0	0	0
Recognized actuarial loss	0	0	0	0
Net pension expense	1	1	2	1
Postretirement Medical Benefits [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	1	1	2	2
Interest cost	1	2	2	3
Expected return on assets	0	0	0	0
Amortization of prior service cost	0	0	0	0
Recognized actuarial loss	0	0	0	0
Net pension expense	$ 2	$ 3	$ 4	$ 5