ALLOWANCE FOR CREDIT LOSSES ON LOANS AND FINANCE LOSSES - Activity in ACL on loans and finance leases (Parenthetical) (Detail) - USD ($) $ in Thousands		12 Months Ended
	Sep. 01, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable Allowance For Credit Losses [Line Items]
Provision for credit losses - (benefit) expense		$ 25,679	$ (61,720)	$ 168,717
Non-PCD | Santander [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Provision for credit losses - (benefit) expense	$ 37,500
Residential Portfolio Segment [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Provision for credit losses - (benefit) expense		(8,734)	(16,957)	22,427
Residential Portfolio Segment [Member] | Non-PCD | Santander [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Provision for credit losses - (benefit) expense	13,500
Commercial Portfolio Segment [Member] | Commercial And Industrial Sector [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Provision for credit losses - (benefit) expense		(1,770)	(8,549)	6,627
Commercial Portfolio Segment [Member] | Mortgage Receivable [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Provision for credit losses - (benefit) expense		(18,994)	(55,358)	81,125
Commercial Portfolio Segment [Member] | Mortgage Receivable [Member] | Non-PCD | Santander [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Provision for credit losses - (benefit) expense	9,200
Consumer Portfolio Segment [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Provision for credit losses - (benefit) expense		$ 57,519	$ 20,552	$ 56,433
Consumer Portfolio Segment [Member] | Non-PCD | Santander [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Provision for credit losses - (benefit) expense	10,200
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member] | Commercial And Industrial Sector [Member] | Santander [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Provision for credit losses - (benefit) expense	$ 4,600