LEASES - Rent Expense and Sublease Rental Income in 2018 (Details) $ in Millions	12 Months Ended
Dec. 31, 2018 USD ($)
Rent Expense and Sublease Rental Income
Rent expense	$ 167
Sublease rental income	(32)
Net rent expense	$ 135

The amount of revenue recognized for the period under subleasing arrangements.

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 20
-Section 55
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=121577943&loc=d3e41620-112719

Name:	us-gaap_OperatingLeasesIncomeStatementSubleaseRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration