EMPLOYEE RETIREMENT PLANS - Net Periodic Pension Cost for Defined-benefit Pension Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net periodic pension cost for the company's defined-benefit pension plans
Pre-tax net loss from accumulated other comprehensive income (loss) into net periodic pension cost	$ 21
Qualified
Net periodic pension cost for the company's defined-benefit pension plans
Service cost	3	$ 3	$ 3
Interest cost	49	47	47
Expected return on plan assets	(44)	(46)	(45)
Amortization of net loss	17	18	11
Net periodic pension cost	25	22	16
Non-Qualified
Net periodic pension cost for the company's defined-benefit pension plans
Interest cost	7	7	7
Amortization of net loss	2	3	2
Net periodic pension cost	$ 9	$ 10	$ 9