GOODWILL AND INTANGIBLE ASSETS - Other Intangibles (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross	$ 82	$ 34
Accumulated Amortization	14	3
Net	$ 68	31
Acquired technology
Finite-Lived Intangible Assets [Line Items]
Useful life	7 years
Gross	$ 21	20
Accumulated Amortization	4	1
Net	17	19
Acquired relationships
Finite-Lived Intangible Assets [Line Items]
Gross	37	11
Accumulated Amortization	5	1
Net	$ 32	10
Naming Rights
Finite-Lived Intangible Assets [Line Items]
Useful life	10 years
Gross	$ 11	0
Accumulated Amortization	1	0
Net	10	0
Other
Finite-Lived Intangible Assets [Line Items]
Gross	13	3
Accumulated Amortization	4	1
Net	$ 9	$ 2
Minimum | Acquired relationships
Finite-Lived Intangible Assets [Line Items]
Useful life	5 years
Minimum | Other
Finite-Lived Intangible Assets [Line Items]
Useful life	2 years
Maximum | Acquired relationships
Finite-Lived Intangible Assets [Line Items]
Useful life	15 years
Maximum | Other
Finite-Lived Intangible Assets [Line Items]
Useful life	7 years