SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Effect of Adoption of ASU 2014-09 on Statement of Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Significant Accounting Policies [Line Items]
Net income	$ 317	$ 503	$ 667	$ 420	$ 114	$ 485	$ 489	$ 371	$ 1,907	$ 1,459	$ 808
Other comprehensive (loss) income:
Foreign currency translation adjustments									(391)	478	(311)
Derivative instrument adjustments, net of tax									12	(14)	1
Unrealized (loss) gain on available-for-sale securities, net of tax									0	(2)	2
Pension and postretirement adjustments, net of tax									(8)	7	5
Reclassification of losses, net of tax									17	11	2
Total other comprehensive (loss) income, net of tax									(370)	480	(301)
Comprehensive income									$ 1,537	1,939	507
As Previously Reported
Significant Accounting Policies [Line Items]
Net income		$ 483	$ 610	$ 398						1,372	780
Other comprehensive (loss) income:
Foreign currency translation adjustments										478	(311)
Derivative instrument adjustments, net of tax										(14)	1
Unrealized (loss) gain on available-for-sale securities, net of tax										(2)	2
Pension and postretirement adjustments, net of tax										7	5
Reclassification of losses, net of tax										11	2
Total other comprehensive (loss) income, net of tax										480	(301)
Comprehensive income										1,852	479
Accounting Standards Update 2014-09 | Adoption of ASU
Significant Accounting Policies [Line Items]
Net income										87	28
Other comprehensive (loss) income:
Foreign currency translation adjustments										0	0
Derivative instrument adjustments, net of tax										0	0
Unrealized (loss) gain on available-for-sale securities, net of tax										0	0
Pension and postretirement adjustments, net of tax										0	0
Reclassification of losses, net of tax										0	0
Total other comprehensive (loss) income, net of tax										0	0
Comprehensive income										$ 87	$ 28