SECURITIES (Securities with Continuous Loss Position) (Details) $ in Thousands	Mar. 31, 2022 USD ($) numberOfSecurities	Dec. 31, 2021 USD ($) numberOfSecurities
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 1,806,218	$ 1,359,199
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	660,540	811,239
Debt Securities, Available-for-sale, Unrealized Loss Position	2,466,758	2,170,438
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	107,337	38,379
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	66,468	12,715
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 173,805	$ 51,094
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | numberOfSecurities	219	97
U.S. Government and agency obligations
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 101,620	$ 0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	26,851	71,306
Debt Securities, Available-for-sale, Unrealized Loss Position	128,471	71,306
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	182	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	574	621
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	756	621
Municipal bonds
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	159,886	40,397
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	0	8,541
Debt Securities, Available-for-sale, Unrealized Loss Position	159,886	48,938
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	16,238	221
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	99
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	16,238	320
Corporate bonds
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	83,374	8,009
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	0	9,938
Debt Securities, Available-for-sale, Unrealized Loss Position	83,374	17,947
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	2,196	121
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	62
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	2,196	183
Mortgage-backed or related securities
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	1,352,151	1,307,411
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	633,689	721,454
Debt Securities, Available-for-sale, Unrealized Loss Position	1,985,840	2,028,865
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	88,005	38,028
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	65,894	11,933
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	153,899	49,961
Asset-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	109,187	3,382
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	0	0
Debt Securities, Available-for-sale, Unrealized Loss Position	109,187	3,382
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	716	9
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 716	$ 9