COMMITMENTS AND CONTINGENCIES - Schedule of ASU Leases (Topic 840) disclosures for prior periods (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Operating Leases
Operating leases, future minimum payments, due current	$ 61	$ 54
Operating leases, future minimum payments, due in two and three years	64	81
Operating leases, future minimum payments, due in four and five years	53	57
Operating leases, future minimum payments, due thereafter	42	41
Total	220	233
Finance Leases
Capital leases, future minimum payments due, next twelve months	1	1
Capital leases, future minimum payments due in two and three years	3	3
Capital leases, future minimum payments due in four and five years	4	3
Capital leases, future minimum payments due thereafter	32	34
Total	40	41
Net rental expenses	$ 76	82
Capital leases imputed interest rate	4.40%
Capital lease imputed interest rate amount	$ 16	$ 18