EMPLOYEE BENEFITS - Schedule of Net Periodic (Income) Cost (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended	12 Months Ended
	Sep. 01, 2014	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Service cost		$ 3	[1]	$ 3	$ 42
Interest cost		52	[1]	53	63
Expected return on plan assets		(73)	[1]	(73)	(84)
Amortization of actuarial loss		10	[1]	14	38
Amortization of prior service cost		0	[1]	0	(1)
Settlement		0	[1]	0	92
Net periodic pension (income) cost		(8)	[1]	(3)	150
Qualified Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost		3	[1]	3	42
Interest cost		47	[1]	48	58
Expected return on plan assets		(73)	[1]	(73)	(84)
Amortization of actuarial loss		9	[1]	13	35
Amortization of prior service cost		0	[1]	0	(1)
Settlement		0	[1]	0	92
Net periodic pension (income) cost		(14)	[1]	(9)	142
Assets transferred to Affiliate plans	129	129	[2]	0	0
Liabilities transferred to Affiliate plans	148	148
Non-Qualified Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost		0	[1]	0	0
Interest cost		5	[1]	5	5
Expected return on plan assets		0	[1]	0	0
Amortization of actuarial loss		1	[1]	1	3
Amortization of prior service cost		0	[1]	0	0
Settlement		0	[1]	0	0
Net periodic pension (income) cost		6	[1]	6	8
Assets transferred to Affiliate plans		0	[2]	0	0
Liabilities transferred to Affiliate plans	$ 7	$ 7

[1] Results for the period September 1, 2014 through December 31, 2014 excluded $129 million in qualified plan assets, $148 million in qualified plan liabilities and $7 million in non-qualified plan liabilities transferred to Affiliates on September 1, 2014.

[2] December 31, 2014 amounts excluded $129 million in qualified plan assets, $148 million in qualified plan liabilities and $7 million in non-qualified plan liabilities transferred to Affiliates on September 1, 2014.