EMPLOYEE RETIREMENT PLANS - Amounts in Consolidated Balance Sheets (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Amounts in the company's consolidated balance sheets
Accrued liabilities	$ (50)	$ (52)
Qualified
Amounts in the company's consolidated balance sheets
Other assets	1	2
Accrued liabilities	(1)	(1)
Other liabilities	(266)	(339)
Total net liability	(266)	(338)
Non-Qualified
Amounts in the company's consolidated balance sheets
Other assets	0	0
Accrued liabilities	(13)	(12)
Other liabilities	(157)	(158)
Total net liability	$ (170)	$ (170)