ALLOWANCE FOR CREDIT LOSSES ON LOANS AND FINANCE LOSSES - Activity in ACL on loans and finance leases (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Sep. 30, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning balance		$ 385,887	$ 155,139	$ 196,362
Allowance established for acquired PCD loans			28,744
Provision (release) for credit losses		(61,720)	168,717	40,225
Charge-offs		(80,710)	(64,540)	(97,587)
Recoveries		25,573	16,662	16,139
Ending balance		269,030	385,887	155,139
ASC 326 [Member] \| Cumulative Effect, Period of Adoption, Adjustment [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Impact of adopting ASC 326				81,165
Residential Portfolio Segment [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning balance		120,311	44,806	50,794
Allowance established for acquired PCD loans			12,739
Provision (release) for credit losses		(16,957)	22,427	14,091
Charge-offs		(33,294)	(11,017)	(22,742)
Recoveries	$ 17,000	4,777	1,519	2,663
Ending balance		74,837	120,311	44,806
Residential Portfolio Segment [Member] \| ASC 326 [Member] \| Cumulative Effect, Period of Adoption, Adjustment [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Impact of adopting ASC 326				49,837
Commercial Portfolio Segment [Member] \| Commercial And Industrial Sector [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning balance		37,944	15,198	32,546
Allowance established for acquired PCD loans			1,830
Provision (release) for credit losses		(8,549)	6,627	(13,696)
Charge-offs		(1,887)	(3,634)	(7,206)
Recoveries		6,776	3,192	3,554
Ending balance		34,284	37,944	15,198
Commercial Portfolio Segment [Member] \| Commercial And Industrial Sector [Member] \| ASC 326 [Member] \| Cumulative Effect, Period of Adoption, Adjustment [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Impact of adopting ASC 326				14,731
Commercial Portfolio Segment [Member] \| Mortgage Receivable [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning balance		109,342	39,194	55,581
Allowance established for acquired PCD loans			9,723
Provision (release) for credit losses		(55,358)	81,125	(1,697)
Charge-offs		(1,494)	(3,330)	(15,088)
Recoveries		281	1,936	398
Ending balance		52,771	109,342	39,194
Commercial Portfolio Segment [Member] \| Mortgage Receivable [Member] \| ASC 326 [Member] \| Cumulative Effect, Period of Adoption, Adjustment [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Impact of adopting ASC 326				(19,306)
Commercial Portfolio Segment [Member] \| Construction Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning balance		5,380	2,370	3,592
Allowance established for acquired PCD loans			0
Provision (release) for credit losses		(1,408)	2,105	(1,496)
Charge-offs		(87)	(76)	(391)
Recoveries		163	184	665
Ending balance		4,048	5,380	2,370
Commercial Portfolio Segment [Member] \| Construction Loans [Member] \| ASC 326 [Member] \| Cumulative Effect, Period of Adoption, Adjustment [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Impact of adopting ASC 326				797
Consumer Portfolio Segment [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning balance		112,910	53,571	53,849
Allowance established for acquired PCD loans			4,452
Provision (release) for credit losses		20,552	56,433	43,023
Charge-offs		(43,948)	(46,483)	(52,160)
Recoveries		13,576	9,831	8,859
Ending balance		$ 103,090	$ 112,910	53,571
Consumer Portfolio Segment [Member] \| ASC 326 [Member] \| Cumulative Effect, Period of Adoption, Adjustment [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Impact of adopting ASC 326				$ 35,106

Impact of new accounting Principle in allowance for credit losses of financing receivable.

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Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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Amount of increase in allowance for credit loss on financing receivable from recovery.

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Amount of writeoff of financing receivable, charged against allowance for credit loss.

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Amount of allowance for credit loss at acquisition date of financing receivable purchased with credit deterioration.

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Amount of expense related to estimated loss from loan and lease transactions.

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