EMPLOYEE BENEFIT PLANS - FUNDED STATUS (DETAILS) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Qualified Defined Benefit [Member]
Benefit obligation
Beginning of year	$ 1,709	$ 1,873
Service cost	33	46	38
Interest cost	81	73	73
Defined Benefit Plan, Settlements, Benefit Obligation	0	0
Actuarial (gain) loss	298	(226)
Benefits paid	(71)	(57)
End of year	2,050	1,709	1,873
Accumulated benefit obligation	1,909	1,603
Plan assets at fair value
Beginning of year	1,769	1,538
Actual return on plan assets	219	205
Employer contributions	0	83
Benefits paid	(71)	(57)
End of year	1,917	1,769	1,538
Funded status (unfunded)	(133)	60
Percent funded	94.00%	104.00%
Defined Benefit Plan, Settlements, Plan Assets	0	0
Postretirement Medical Benefits [Member]
Benefit obligation
Beginning of year	89	117
Service cost	3	5	5
Interest cost	4	4	5
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments	(25)	0
Actuarial (gain) loss	12	(35)
Benefits paid	(2)	(2)
End of year	81	89	117
Plan assets at fair value
Beginning of year	0	0
Employer contributions	2	2
Benefits paid	(2)	(2)
End of year	0	0	0
Funded status (unfunded)	(81)	(89)
Sick Leave [Domain] | Postretirement Medical Benefits [Member]
Benefit obligation
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments	(5)
Special Charges [Member] | Postretirement Medical Benefits [Member]
Benefit obligation
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments	$ (20)