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, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value
Total Assets at Fair Value	$ 658	$ 691	$ 659
US | Common and Preferred Stocks
Fair Value
Total Assets at Fair Value	253	252
US | Private Equity and Hedge Funds
Fair Value
Total Assets at Fair Value	52	59
US | Corporate Debt Securities
Fair Value
Total Assets at Fair Value	44	48
US | Government and Other Debt Securities
Fair Value
Total Assets at Fair Value	67	66
US | Common Collective Trust Fund
Fair Value
Total Assets at Fair Value	4	5
US | Short-Term and other Investments
Fair Value
Total Assets at Fair Value	2	1
International | Common and Preferred Stocks
Fair Value
Total Assets at Fair Value	69	65
International | Private Equity and Hedge Funds
Fair Value
Total Assets at Fair Value	24	27
International | Corporate Debt Securities
Fair Value
Total Assets at Fair Value	48	75
International | Government and Other Debt Securities
Fair Value
Total Assets at Fair Value	53	51
International | Short-Term and other Investments
Fair Value
Total Assets at Fair Value	42	42
Assets at Fair Value (Level 1)
Fair Value
Total Assets at Fair Value	291	292
Assets at Fair Value (Level 1) | US | Common and Preferred Stocks
Fair Value
Total Assets at Fair Value	127	136
Assets at Fair Value (Level 1) | US | Corporate Debt Securities
Fair Value
Total Assets at Fair Value	18	15
Assets at Fair Value (Level 1) | US | Government and Other Debt Securities
Fair Value
Total Assets at Fair Value	64	64
Assets at Fair Value (Level 1) | US | Short-Term and other Investments
Fair Value
Total Assets at Fair Value	2
Assets at Fair Value (Level 1) | International | Common and Preferred Stocks
Fair Value
Total Assets at Fair Value	55	50
Assets at Fair Value (Level 1) | International | Government and Other Debt Securities
Fair Value
Total Assets at Fair Value	23	24
Assets at Fair Value (Level 1) | International | Short-Term and other Investments
Fair Value
Total Assets at Fair Value	2	3
Level 2
Fair Value
Total Assets at Fair Value	272	295
Level 2 | US | Common and Preferred Stocks
Fair Value
Total Assets at Fair Value	126	116
Level 2 | US | Corporate Debt Securities
Fair Value
Total Assets at Fair Value	26	33
Level 2 | US | Government and Other Debt Securities
Fair Value
Total Assets at Fair Value	3	2
Level 2 | US | Common Collective Trust Fund
Fair Value
Total Assets at Fair Value	4	5
Level 2 | US | Short-Term and other Investments
Fair Value
Total Assets at Fair Value		1
Level 2 | International | Common and Preferred Stocks
Fair Value
Total Assets at Fair Value	14	15
Level 2 | International | Corporate Debt Securities
Fair Value
Total Assets at Fair Value	48	75
Level 2 | International | Government and Other Debt Securities
Fair Value
Total Assets at Fair Value	30	27
Level 2 | International | Short-Term and other Investments
Fair Value
Total Assets at Fair Value	21	21
Level 3
Fair Value
Total Assets at Fair Value	95	104
Level 3 | US | Private Equity and Hedge Funds
Fair Value
Total Assets at Fair Value	52	59
Level 3 | International | Private Equity and Hedge Funds
Fair Value
Total Assets at Fair Value	24	27
Level 3 | International | Short-Term and other Investments
Fair Value
Total Assets at Fair Value	$ 19	$ 18