SECURITIES (Schedule of Securities) (Details) - USD ($)	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Schedule of Securities [Line Items]
Debt Securities, Trading, Amortized Cost	$ 27,203,000		$ 27,203,000
Securities—trading	27,886,000		26,981,000
Debt Securities, Available-for-sale, Amortized Cost, Total	3,391,472,000		3,653,160,000
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1,650,000		36,927,000
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	298,700,000		51,094,000
Debt Securities, Available-for-sale, Allowance for Credit Loss	0		0
Debt Securities, Available-for-sale	3,094,422,000		3,638,993,000
Held-to-maturity Securities, Amortized Cost	1,152,189,000		521,355,000
Held-to-maturity Securities, Gross Unrealized Gains	499,000		21,917,000
Held-to-maturity Securities, Gross Unrealized Losses	116,387,000		1,419,000
Securities—held-to-maturity	1,036,301,000		541,853,000
Debt Securities, Held-to-maturity, Allowance for Credit Loss	424,000		(433,000)
debt securities, held-to-maturity, accrued interest receivable	4,900,000		3,300,000
Debt Securities, Available-for-Sale, Accrued Interest Receivable	10,400,000
U.S. Government and agency obligations
Schedule of Securities [Line Items]
Debt Securities, Available-for-sale, Amortized Cost, Total	191,842,000		201,101,000
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	177,000		852,000
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	1,126,000		621,000
Debt Securities, Available-for-sale, Allowance for Credit Loss	0		0
Debt Securities, Available-for-sale	190,893,000		201,332,000
Held-to-maturity Securities, Amortized Cost	313,000		316,000
Held-to-maturity Securities, Gross Unrealized Gains	0		3,000
Held-to-maturity Securities, Gross Unrealized Losses	4,000		0
Securities—held-to-maturity	309,000		319,000
Debt Securities, Held-to-maturity, Allowance for Credit Loss	0	$ 0	0	$ 0	$ 0	$ 0
Municipal bonds
Schedule of Securities [Line Items]
Debt Securities, Available-for-sale, Amortized Cost, Total	283,124,000		293,761,000
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	675,000		15,171,000
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	32,499,000		320,000
Debt Securities, Available-for-sale, Allowance for Credit Loss	0		0
Debt Securities, Available-for-sale	251,300,000		308,612,000
Held-to-maturity Securities, Amortized Cost	502,416,000		420,555,000
Held-to-maturity Securities, Gross Unrealized Gains	499,000		20,743,000
Held-to-maturity Securities, Gross Unrealized Losses	58,474,000		1,393,000
Securities—held-to-maturity	444,441,000		439,905,000
Debt Securities, Held-to-maturity, Allowance for Credit Loss	196,000	191,000	203,000	64,000	61,000	59,000
Corporate bonds
Schedule of Securities [Line Items]
Debt Securities, Trading, Amortized Cost	27,203,000		27,203,000
Securities—trading	27,886,000		26,981,000
Debt Securities, Available-for-sale, Amortized Cost, Total	133,461,000		114,427,000
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	12,000		3,103,000
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	5,969,000		183,000
Debt Securities, Available-for-sale, Allowance for Credit Loss	0		0
Debt Securities, Available-for-sale	127,504,000		117,347,000
Held-to-maturity Securities, Amortized Cost	3,027,000		3,092,000
Held-to-maturity Securities, Gross Unrealized Gains	0		0
Held-to-maturity Securities, Gross Unrealized Losses	19,000		3,000
Securities—held-to-maturity	3,008,000		3,089,000
Debt Securities, Held-to-maturity, Allowance for Credit Loss	228,000	229,000	230,000	46,000	37,000	35,000
Mortgage-backed or related securities
Schedule of Securities [Line Items]
Debt Securities, Available-for-sale, Amortized Cost, Total	2,580,045,000		2,837,480,000
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	697,000		17,749,000
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	257,269,000		49,961,000
Debt Securities, Available-for-sale, Allowance for Credit Loss	0		0
Debt Securities, Available-for-sale	2,323,473,000		2,805,268,000
Held-to-maturity Securities, Amortized Cost	646,433,000		97,392,000
Held-to-maturity Securities, Gross Unrealized Gains	0		1,171,000
Held-to-maturity Securities, Gross Unrealized Losses	57,890,000		23,000
Securities—held-to-maturity	588,543,000		98,540,000
Debt Securities, Held-to-maturity, Allowance for Credit Loss	0	$ 0	0	$ 0	$ 0	$ 0
Asset-backed securities
Schedule of Securities [Line Items]
Debt Securities, Available-for-sale, Amortized Cost, Total	203,000,000		206,391,000
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	89,000		52,000
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	1,837,000		9,000
Debt Securities, Available-for-sale, Allowance for Credit Loss	0		0
Debt Securities, Available-for-sale	$ 201,252,000		$ 206,434,000