COMPREHENSIVE INCOME (LOSS) - BALANCES INCLUDED IN AOCI, NET OF TAX, IN THE CONSOLIDATED BALANCE SHEETS (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	$ 5,034	$ 4,890	$ 4,935	$ 4,608	$ 4,649	$ 5,048	$ 4,935	$ 5,048
Tax benefit (expense)		0
Net (decrease) increase in other comprehensive loss	(56)	43	(90)	67	68	(112)	(103)	23
Ending Balance	5,063	5,034	4,890	4,720	4,608	4,649	5,063	4,720
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(511)	(554)	(464)	(646)	(714)	(602)	(464)	(602)
Other comprehensive (loss) income before reclassifications and tax impact	(50)	35	(68)	47	62	(108)
Tax benefit (expense)	(11)	3	(26)	17	5	(6)
Other comprehensive (loss) income, net of tax, before reclassifications	(61)	38	(94)	64	67	(114)
Amounts reclassified from accumulated other comprehensive income, net of tax	5	5	4	3	1	2
Net (decrease) increase in other comprehensive loss	(56)	43	(90)	67	68	(112)
Ending Balance	(567)	(511)	(554)	(579)	(646)	(714)	(567)	(579)
Foreign Currency Translation Gain (Loss)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(249)	(286)	(187)	(414)	(489)	(370)	(187)	(370)
Other comprehensive (loss) income before reclassifications and tax impact	(59)	31	(74)	67	77	(117)
Tax benefit (expense)	(9)	6	(25)	17	(2)	(2)
Other comprehensive (loss) income, net of tax, before reclassifications	(68)	37	(99)	84	75	(119)
Amounts reclassified from accumulated other comprehensive income, net of tax	0	0	0	0	0	0
Net (decrease) increase in other comprehensive loss	(68)	37	(99)	84	75	(119)
Ending Balance	(317)	(249)	(286)	(330)	(414)	(489)	(317)	(330)
Gain (Loss) on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(23)	(27)	(25)	(23)	(23)	(11)	(25)	(11)
Other comprehensive (loss) income before reclassifications and tax impact	6	3	(6)	(3)	0	(16)
Tax benefit (expense)	(1)	(2)	2	(2)	0	4
Other comprehensive (loss) income, net of tax, before reclassifications	5	1	(4)	(5)	0	(12)
Amounts reclassified from accumulated other comprehensive income, net of tax	3	3	2	1	0	0
Net (decrease) increase in other comprehensive loss	8	4	(2)	(4)	0	(12)
Ending Balance	(15)	(23)	(27)	(27)	(23)	(23)	(15)	(27)
Gain (Loss) on Net Investment and Fair Value Hedges
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(112)	(112)	(119)	(92)	(84)	(101)	(119)	(101)
Other comprehensive (loss) income before reclassifications and tax impact	3	1	9	(17)	(15)	25
Tax benefit (expense)	(1)	(1)	(2)	2	7	(8)
Other comprehensive (loss) income, net of tax, before reclassifications	2	0	7	(15)	(8)	17
Amounts reclassified from accumulated other comprehensive income, net of tax	0	0	0	0	0	0
Net (decrease) increase in other comprehensive loss	2	0	7	(15)	(8)	17
Ending Balance	(110)	(112)	(112)	(107)	(92)	(84)	(110)	(107)
Pension Liability Gain (Loss)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(127)	(129)	(133)	(117)	(118)	(120)	(133)	(120)
Other comprehensive (loss) income before reclassifications and tax impact	0	0	3	0	0	0
Tax benefit (expense)	0		(1)	0	0	0
Other comprehensive (loss) income, net of tax, before reclassifications	0	0	2	0	0	0
Amounts reclassified from accumulated other comprehensive income, net of tax	2	2	2	2	1	2
Net (decrease) increase in other comprehensive loss	2	2	4	2	1	2
Ending Balance	$ (125)	$ (127)	$ (129)	$ (115)	$ (117)	$ (118)	$ (125)	$ (115)