SECURITIES (Securities with Continuous Loss Position) (Details) $ in Thousands	Sep. 30, 2021 USD ($) numberOfSecurities	Dec. 31, 2020 USD ($) numberOfSecurities
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 1,611,688	$ 189,078
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	88,017	58,616
Debt Securities, Available-for-sale, Unrealized Loss Position	1,699,705	247,694
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	40,591	1,135
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	1,743	1,004
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 42,334	$ 2,139
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions \| numberOfSecurities	84	54
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	$ 40,115	$ 3,126
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	33,447	50,603
Debt Securities, Available-for-sale, Unrealized Loss Position	73,562	53,729
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	39	8
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	561	927
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	600	935
Municipal bonds
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	60,522	495
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	0	0
Debt Securities, Available-for-sale, Unrealized Loss Position	60,522	495
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	788	2
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	788	2
Corporate bonds
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	7,937	3,586
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	0	0
Debt Securities, Available-for-sale, Unrealized Loss Position	7,937	3,586
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	63	79
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	63	79
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	1,503,114	181,871
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	54,570	2,337
Debt Securities, Available-for-sale, Unrealized Loss Position	1,557,684	184,208
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	39,701	1,046
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	1,182	14
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 40,883	1,060
Asset-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months		0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer		5,676
Debt Securities, Available-for-sale, Unrealized Loss Position		5,676
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		63
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss		$ 63

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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