DERIVATIVES (Offsetting of Financial Assets) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Offsetting Assets [Line Items]
Gross Amounts of Recognized Assets, Total derivatives subject to a master netting arrangement or similar arrangement	$ 1,628,951	$ 553,289
Gross Amounts Offset in the Condensed Consolidated Balance Sheet, Total Derivative Assets	602	435
Net Amounts of Assets Presented in the Condensed Consolidated Balance Sheet, Total derivatives subject to a master netting arrangement or similar arrangement	1,628,349	552,854
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet, Collateral Received, Total Derivative Assets	156,560	69,227
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet, Net Amount, Total derivatives subject to a master netting arrangement or similar arrangement	1,471,789	483,627
Total derivatives not subject to a master netting arrangement or similar arrangement	16,435	3,042
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet, Collateral Received	0
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet, Net Amount	16,435	3,042
Gross Amounts of Recognized Assets, Total Derivative Assets	1,645,386	556,331
Net Amounts of Assets Presented in the Condensed Consolidated Balance Sheet, Total Derivative Assets	1,644,784	555,896
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet, Collateral Received, Total Derivative Assets	156,560	69,227
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet - Net Amount, Total Derivative Assets	1,488,224	486,669
Other derivative activities
Offsetting Assets [Line Items]
Gross Amounts of Recognized Assets, Total derivatives subject to a master netting arrangement or similar arrangement	1,378,524	524,258
Gross Amounts Offset in the Condensed Consolidated Balance Sheet, Total Derivative Assets	602	435
Net Amounts of Assets Presented in the Condensed Consolidated Balance Sheet, Total derivatives subject to a master netting arrangement or similar arrangement	1,377,922	523,823
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet, Collateral Received, Total Derivative Assets	11,880	51,437
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet, Net Amount, Total derivatives subject to a master netting arrangement or similar arrangement	1,366,042	472,386
Cash flow hedges
Offsetting Assets [Line Items]
Gross Amounts of Recognized Assets, Total derivatives subject to a master netting arrangement or similar arrangement	250,427	29,031
Gross Amounts Offset in the Condensed Consolidated Balance Sheet, Total Derivative Assets	0	0
Net Amounts of Assets Presented in the Condensed Consolidated Balance Sheet, Total derivatives subject to a master netting arrangement or similar arrangement	250,427	29,031
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet, Collateral Received, Total Derivative Assets	144,680	17,790
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet, Net Amount, Total derivatives subject to a master netting arrangement or similar arrangement	$ 105,747	$ 11,241