BASIS OF PRESENTATION AND CONSOLIDATION - Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Jan. 01, 2023	Dec. 31, 2022
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses on off-balance sheet credit exposures	$ 616,938	$ 585,364	$ 519,158		$ 508,955
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses on off-balance sheet credit exposures	$ 412,190	$ 388,033	$ 330,673		$ 330,275
Retained Earnings | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses on off-balance sheet credit exposures				$ (17,825)