CREDIT LOSSES - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease to equity	$ (571,090)	$ (572,395)	$ (571,522)	$ (551,611)
Impact of ASC 326 Adoption
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease to equity		3,298
Tax impact for change in accounting principle	1,109
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease to equity	$ (258,972)	(259,903)	$ (196,583)	$ (182,148)
Retained Earnings | Impact of ASC 326 Adoption
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease to equity		3,298
Tax impact for change in accounting principle		$ 1,109