CHANGE IN ACCUMULATED OTHER COMPREHENSIVE (LOSS) INCOME - Components of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			$ 1,939,099
Other comprehensive income (loss)	$ (202,500)	$ (25,566)	(683,420)	$ (70,785)
Less: Amounts reclassified from accumulated other comprehensive (loss) income	5,899	(158)	5,709	(708)
Net current-period other comprehensive (loss) income	(196,601)	(25,724)	(677,711)	(71,493)
Ending balance	2,103,593		2,103,593
Amortization of unrealized gain (loss) on securities reclassified to held-to-maturity, tax expense	(1,884)	9	35,955	23
Fannie Mae (FNMA) mortgage-backed securities (MBS)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Amortization of unrealized gain (loss) on securities reclassified to held-to-maturity, tax expense			119,800
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(518,878)	10,238	(37,768)	56,007
Ending balance	(715,479)	(15,486)	(715,479)	(15,486)
Net change in investment securities available-for-sale
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(395,213)	14,147	(33,873)	59,882
Other comprehensive income (loss)	(202,520)	(25,639)	(563,860)	(71,124)
Less: Amounts reclassified from accumulated other comprehensive (loss) income	0	(2)	0	(252)
Net current-period other comprehensive (loss) income	(202,520)	(25,641)	(563,860)	(71,376)
Ending balance	(597,733)	(11,494)	(597,733)	(11,494)
Net change in investment securities held-to-maturity
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(119,649)	232	175	276
Other comprehensive income (loss)	(1)	(1)	(119,769)	1
Less: Amounts reclassified from accumulated other comprehensive (loss) income	5,967	(28)	5,911	(74)
Net current-period other comprehensive (loss) income	5,966	(29)	(113,858)	(73)
Ending balance	(113,683)	203	(113,683)	203
Net change in defined benefit plan
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(4,746)	(4,828)	(4,691)	(4,788)
Other comprehensive income (loss)	(4)	(8)	(4)	(17)
Less: Amounts reclassified from accumulated other comprehensive (loss) income	(27)	(15)	(82)	(46)
Net current-period other comprehensive (loss) income	(31)	(23)	(86)	(63)
Ending balance	(4,777)	(4,851)	(4,777)	(4,851)
Net change in fair value of derivatives used for cash flow hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	189	423	268	646
Other comprehensive income (loss)	0	0	0	0
Less: Amounts reclassified from accumulated other comprehensive (loss) income	(41)	(113)	(120)	(336)
Net current-period other comprehensive (loss) income	(41)	(113)	(120)	(336)
Ending balance	148	310	148	310
Net change in equity method investments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	541	264	353	(9)
Other comprehensive income (loss)	25	82	213	355
Less: Amounts reclassified from accumulated other comprehensive (loss) income	0	0	0	0
Net current-period other comprehensive (loss) income	25	82	213	355
Ending balance	$ 566	$ 346	$ 566	$ 346

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount after tax, before reclassification adjustments, of other comprehensive income (loss), attributable to parent.

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Amount after tax of other comprehensive income (loss) attributable to parent entity.

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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