EMPLOYEE RETIREMENT PLANS - Qualified Defined-benefit Pension Plan Assets at Fair Value by Level within the Fair Value Hierarchy (Details) - Qualified - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value
Total assets at fair value	$ 717	$ 658	$ 691
Total asset at net asset value	185	123
UNITED STATES | Common and Preferred Stocks
Fair Value
Total assets at fair value	260	253
Total asset at net asset value	118	93
UNITED STATES | Private Equity and Hedge Funds
Fair Value
Total assets at fair value	37	52
Total asset at net asset value		3
UNITED STATES | Corporate Debt Securities
Fair Value
Total assets at fair value	57	44
Total asset at net asset value	2
UNITED STATES | Government and Other Debt Securities
Fair Value
Total assets at fair value	50	67
UNITED STATES | Common Collective Trust Fund
Fair Value
Total assets at fair value	4	4
UNITED STATES | Short-Term and other Investments
Fair Value
Total assets at fair value	2	2
International | Common and Preferred Stocks
Fair Value
Total assets at fair value	90	69
Total asset at net asset value	16	7
International | Private Equity and Hedge Funds
Fair Value
Total assets at fair value	56	24
Total asset at net asset value	32	4
International | Corporate Debt Securities
Fair Value
Total assets at fair value	43	48
Total asset at net asset value	17	16
International | Government and Other Debt Securities
Fair Value
Total assets at fair value	80	53
International | Short-Term and other Investments
Fair Value
Total assets at fair value	38	42
Level 1
Fair Value
Total assets at fair value	323	291
Level 1 | UNITED STATES | Common and Preferred Stocks
Fair Value
Total assets at fair value	142	127
Level 1 | UNITED STATES | Corporate Debt Securities
Fair Value
Total assets at fair value	27	18
Level 1 | UNITED STATES | Government and Other Debt Securities
Fair Value
Total assets at fair value	46	64
Level 1 | UNITED STATES | Short-Term and other Investments
Fair Value
Total assets at fair value	2	2
Level 1 | International | Common and Preferred Stocks
Fair Value
Total assets at fair value	74	55
Level 1 | International | Government and Other Debt Securities
Fair Value
Total assets at fair value	27	23
Level 1 | International | Short-Term and other Investments
Fair Value
Total assets at fair value	5	2
Level 2
Fair Value
Total assets at fair value	130	156
Level 2 | UNITED STATES | Common and Preferred Stocks
Fair Value
Total assets at fair value		33
Level 2 | UNITED STATES | Corporate Debt Securities
Fair Value
Total assets at fair value	28	26
Level 2 | UNITED STATES | Government and Other Debt Securities
Fair Value
Total assets at fair value	4	3
Level 2 | UNITED STATES | Common Collective Trust Fund
Fair Value
Total assets at fair value	4	4
Level 2 | International | Common and Preferred Stocks
Fair Value
Total assets at fair value		7
Level 2 | International | Corporate Debt Securities
Fair Value
Total assets at fair value	26	32
Level 2 | International | Government and Other Debt Securities
Fair Value
Total assets at fair value	53	30
Level 2 | International | Short-Term and other Investments
Fair Value
Total assets at fair value	15	21
Level 3
Fair Value
Total assets at fair value	79	88
Level 3 | UNITED STATES | Private Equity and Hedge Funds
Fair Value
Total assets at fair value	37	49
Level 3 | International | Private Equity and Hedge Funds
Fair Value
Total assets at fair value	24	20
Level 3 | International | Short-Term and other Investments
Fair Value
Total assets at fair value	$ 18	$ 19