EMPLOYEE RETIREMENT PLANS - Qualified Defined-benefit Pension Plan Assets at Fair Value by Level within the Fair Value Hierarchy (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Private Equity And Hedge Funds [Member]
Fair Value
Private equity funds	$ 19,000,000	$ 93,000,000
Qualified
Fair Value
Private equity funds	780,000,000	670,000,000	$ 695,000,000
Valued at NAV	464,000,000	376,000,000
Fair Value, Inputs, Level 1 | Qualified
Fair Value
Private equity funds	239,000,000	184,000,000
Fair Value, Inputs, Level 2 | Qualified
Fair Value
Private equity funds	58,000,000	51,000,000
Fair Value, Inputs, Level 3 | Qualified
Fair Value
Private equity funds	19,000,000	59,000,000
UNITED STATES | Qualified | Common And Preferred Stock [Member]
Fair Value
Private equity funds	167,000,000	102,000,000
Valued at NAV	82,000,000	21,000,000
UNITED STATES | Qualified | Private Equity And Hedge Funds [Member]
Fair Value
Private equity funds	2,000,000	32,000,000
Valued at NAV	0	0
UNITED STATES | Qualified | Corporate Debt Securities [Member]
Fair Value
Private equity funds	198,000,000	136,000,000
Valued at NAV	124,000,000	102,000,000
UNITED STATES | Qualified | US Treasury and Government [Member]
Fair Value
Private equity funds	151,000,000	132,000,000
Valued at NAV	148,000,000	130,000,000
UNITED STATES | Qualified | Common Collective Trust Fund [Member]
Fair Value
Private equity funds	4,000,000	4,000,000
Valued at NAV	0	0
UNITED STATES | Qualified | Short Term And Other Investments [Member]
Fair Value
Private equity funds	2,000,000	1,000,000
Valued at NAV	0	0
UNITED STATES | Fair Value, Inputs, Level 1 | Qualified | Common And Preferred Stock [Member]
Fair Value
Private equity funds	85,000,000	81,000,000
UNITED STATES | Fair Value, Inputs, Level 1 | Qualified | Private Equity And Hedge Funds [Member]
Fair Value
Private equity funds	0	0
UNITED STATES | Fair Value, Inputs, Level 1 | Qualified | Corporate Debt Securities [Member]
Fair Value
Private equity funds	74,000,000	34,000,000
UNITED STATES | Fair Value, Inputs, Level 1 | Qualified | US Treasury and Government [Member]
Fair Value
Private equity funds	0	0
UNITED STATES | Fair Value, Inputs, Level 1 | Qualified | Common Collective Trust Fund [Member]
Fair Value
Private equity funds	0	0
UNITED STATES | Fair Value, Inputs, Level 1 | Qualified | Short Term And Other Investments [Member]
Fair Value
Private equity funds	2,000,000	1,000,000
UNITED STATES | Fair Value, Inputs, Level 2 | Qualified | Common And Preferred Stock [Member]
Fair Value
Private equity funds	0	0
UNITED STATES | Fair Value, Inputs, Level 2 | Qualified | Private Equity And Hedge Funds [Member]
Fair Value
Private equity funds	0	0
UNITED STATES | Fair Value, Inputs, Level 2 | Qualified | Corporate Debt Securities [Member]
Fair Value
Private equity funds	0	0
UNITED STATES | Fair Value, Inputs, Level 2 | Qualified | US Treasury and Government [Member]
Fair Value
Private equity funds	3,000,000	2,000,000
UNITED STATES | Fair Value, Inputs, Level 2 | Qualified | Common Collective Trust Fund [Member]
Fair Value
Private equity funds	4,000,000	4,000,000
UNITED STATES | Fair Value, Inputs, Level 2 | Qualified | Short Term And Other Investments [Member]
Fair Value
Private equity funds	0	0
UNITED STATES | Fair Value, Inputs, Level 3 | Qualified | Common And Preferred Stock [Member]
Fair Value
Private equity funds	0	0
UNITED STATES | Fair Value, Inputs, Level 3 | Qualified | Private Equity And Hedge Funds [Member]
Fair Value
Private equity funds	2,000,000	32,000,000
UNITED STATES | Fair Value, Inputs, Level 3 | Qualified | Corporate Debt Securities [Member]
Fair Value
Private equity funds	0	0
UNITED STATES | Fair Value, Inputs, Level 3 | Qualified | US Treasury and Government [Member]
Fair Value
Private equity funds	0	0
UNITED STATES | Fair Value, Inputs, Level 3 | Qualified | Common Collective Trust Fund [Member]
Fair Value
Private equity funds	0	0
UNITED STATES | Fair Value, Inputs, Level 3 | Qualified | Short Term And Other Investments [Member]
Fair Value
Private equity funds	0	0
Foreign Plan [Member] | Qualified | Common And Preferred Stock [Member]
Fair Value
Private equity funds	157,000,000	126,000,000
Valued at NAV	110,000,000	89,000,000
Foreign Plan [Member] | Qualified | Private Equity And Hedge Funds [Member]
Fair Value
Private equity funds	17,000,000	61,000,000
Valued at NAV	0	34,000,000
Foreign Plan [Member] | Qualified | Corporate Debt Securities [Member]
Fair Value
Private equity funds	1,000,000	1,000,000
Valued at NAV	0	0
Foreign Plan [Member] | Qualified | Debt Security, Government, Non-US [Member]
Fair Value
Private equity funds	67,000,000	62,000,000
Valued at NAV	0	0
Foreign Plan [Member] | Qualified | Buy-in Annuity [Member]
Fair Value
Private equity funds	12,000,000	11,000,000
Valued at NAV	0	0
Foreign Plan [Member] | Qualified | Short Term And Other Investments [Member]
Fair Value
Private equity funds	2,000,000	2,000,000
Valued at NAV	0	0
Foreign Plan [Member] | Fair Value, Inputs, Level 1 | Qualified | Common And Preferred Stock [Member]
Fair Value
Private equity funds	47,000,000	37,000,000
Foreign Plan [Member] | Fair Value, Inputs, Level 1 | Qualified | Private Equity And Hedge Funds [Member]
Fair Value
Private equity funds	0	0
Foreign Plan [Member] | Fair Value, Inputs, Level 1 | Qualified | Corporate Debt Securities [Member]
Fair Value
Private equity funds	0	0
Foreign Plan [Member] | Fair Value, Inputs, Level 1 | Qualified | Debt Security, Government, Non-US [Member]
Fair Value
Private equity funds	29,000,000	29,000,000
Foreign Plan [Member] | Fair Value, Inputs, Level 1 | Qualified | Buy-in Annuity [Member]
Fair Value
Private equity funds	0	0
Foreign Plan [Member] | Fair Value, Inputs, Level 1 | Qualified | Short Term And Other Investments [Member]
Fair Value
Private equity funds	2,000,000	2,000,000
Foreign Plan [Member] | Fair Value, Inputs, Level 2 | Qualified | Common And Preferred Stock [Member]
Fair Value
Private equity funds	0	0
Foreign Plan [Member] | Fair Value, Inputs, Level 2 | Qualified | Private Equity And Hedge Funds [Member]
Fair Value
Private equity funds	0	0
Foreign Plan [Member] | Fair Value, Inputs, Level 2 | Qualified | Corporate Debt Securities [Member]
Fair Value
Private equity funds	1,000,000	1,000,000
Foreign Plan [Member] | Fair Value, Inputs, Level 2 | Qualified | Debt Security, Government, Non-US [Member]
Fair Value
Private equity funds	38,000,000	33,000,000
Foreign Plan [Member] | Fair Value, Inputs, Level 2 | Qualified | Buy-in Annuity [Member]
Fair Value
Private equity funds	12,000,000	11,000,000
Foreign Plan [Member] | Fair Value, Inputs, Level 2 | Qualified | Short Term And Other Investments [Member]
Fair Value
Private equity funds	0	0
Foreign Plan [Member] | Fair Value, Inputs, Level 3 | Qualified | Common And Preferred Stock [Member]
Fair Value
Private equity funds	0	0
Foreign Plan [Member] | Fair Value, Inputs, Level 3 | Qualified | Private Equity And Hedge Funds [Member]
Fair Value
Private equity funds	17,000,000	27,000,000
Foreign Plan [Member] | Fair Value, Inputs, Level 3 | Qualified | Corporate Debt Securities [Member]
Fair Value
Private equity funds	0	0
Foreign Plan [Member] | Fair Value, Inputs, Level 3 | Qualified | Debt Security, Government, Non-US [Member]
Fair Value
Private equity funds	0	0
Foreign Plan [Member] | Fair Value, Inputs, Level 3 | Qualified | Buy-in Annuity [Member]
Fair Value
Private equity funds	0	0
Foreign Plan [Member] | Fair Value, Inputs, Level 3 | Qualified | Short Term And Other Investments [Member]
Fair Value
Private equity funds	$ 0	$ 0