EMPLOYEE BENEFITS - Fair Value of Plan Assets (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		$ 114	$ 104
Investments measured at net asset value	[1]	1,024	918
Managed portfolio | Cash and money market funds
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value			2
Managed portfolio | U.S. government obligations
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		8	10
Managed portfolio | Non-U.S. government obligations
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		2
Managed portfolio | Municipal obligations
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		1	2
Managed portfolio | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		102	89
Managed portfolio | Asset-backed securities
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		1	1
Level 1
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		0	0
Level 1 | Managed portfolio | Cash and money market funds
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value			0
Level 1 | Managed portfolio | U.S. government obligations
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		0	0
Level 1 | Managed portfolio | Non-U.S. government obligations
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		0
Level 1 | Managed portfolio | Municipal obligations
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		0	0
Level 1 | Managed portfolio | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		0	0
Level 1 | Managed portfolio | Asset-backed securities
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		0	0
Level 2
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		114	104
Level 2 | Managed portfolio | Cash and money market funds
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value			2
Level 2 | Managed portfolio | U.S. government obligations
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		8	10
Level 2 | Managed portfolio | Non-U.S. government obligations
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		2
Level 2 | Managed portfolio | Municipal obligations
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		1	2
Level 2 | Managed portfolio | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		102	89
Level 2 | Managed portfolio | Asset-backed securities
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		1	1
Level 3
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		0	0
Level 3 | Managed portfolio | Cash and money market funds
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value			0
Level 3 | Managed portfolio | U.S. government obligations
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		0	0
Level 3 | Managed portfolio | Non-U.S. government obligations
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		0
Level 3 | Managed portfolio | Municipal obligations
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		0	0
Level 3 | Managed portfolio | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		0	0
Level 3 | Managed portfolio | Asset-backed securities
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		0	0
Investment
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		$ 1,138	$ 1,022

[1] Certain investments that were measured at net asset value per share (or its equivalent) have not been classified in the fair value hierarchy.