LEGAL PROCEEDINGS - Securities and RICO Class Actions and Related Matters (Details) $ in Millions			1 Months Ended	3 Months Ended	12 Months Ended
	Dec. 16, 2019 USD ($)	Dec. 07, 2017 insurance_policy_period	Oct. 31, 2015 case	Mar. 31, 2020 USD ($) group case	Dec. 31, 2019 USD ($) group action	Dec. 31, 2015 case	Sep. 13, 2019 shareholder	Sep. 10, 2019 shareholder	Feb. 15, 2019 entity
Canada
Loss Contingencies [Line Items]
Number of suits filed						6
Canada | Violation of Canadian Provincial Securities Legislation
Loss Contingencies [Line Items]
Number of suits filed but not yet served | action					2
Number of entities, exercised opt-out right, pursuing action | entity									1
US Securities Litigation | New Jersey
Loss Contingencies [Line Items]
Number of groups of investors filing action | group					35
Number of claims dismissed				2
Number of groups of investors filing action, remain pending | group				33
US Securities Litigation | New Jersey | Unfavorable Regulatory Action
Loss Contingencies [Line Items]
Number of suits filed			4
Insurance Coverage Lawsuit
Loss Contingencies [Line Items]
Number of distinct insurance policy periods | insurance_policy_period		2
Derivative Lawsuits
Loss Contingencies [Line Items]
Number of alleged stockholders, filed lawsuits | shareholder							2	2
Settled Litigation | US Securities Litigation | New Jersey
Loss Contingencies [Line Items]
Settlement, agreed to pay | $	$ 1,210			$ 1,010	$ 1,210