INCOME TAXES - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Loss Carryforwards [Line Items]
Increase in tax provision from remeasurement to deferred tax asset due to Tax Reform Law			$ 133
Decrease to tax provision from revisions of Tax Reform Law estimates		$ 39
Benefit on sale of business	$ 0	272	0
Net operating losses to carryforward related to prior acquisitions	114
Valuation allowances on net operating loss carryforwards related to prior acquisitions	45	$ 54
Puerto Rico
Operating Loss Carryforwards [Line Items]
Repatriation tax for undistributed foreign earnings			$ 10
Capital Loss Carryforward
Operating Loss Carryforwards [Line Items]
Capital loss carryforward	$ 2