Loans - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest income recognized	$ 4,000	$ 3,000
Transfers Of Financial Assets Accounted For As Sale Initial Fair Value Of Assets Obtained As Proceeds	305,597	743,847
Loans held in portfolio, net of unearned income	32,077,769	29,240,557
Non-accrual with no allowance	177,104	236,858
Troubled debt restructurings	1,644,647	1,656,822
Trading account debt securities
Accounts, Notes, Loans and Financing Receivable [Line Items]
Transfers Of Financial Assets Accounted For As Sale Initial Fair Value Of Assets Obtained As Proceeds	300,279	732,533
Accruing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled debt restructurings	1,495,309	1,468,966
Collateral Pledged
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held in portfolio, net of unearned income	406,836	497,988
Non-accrual with no allowance	177,000	237,000
Past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held in portfolio, net of unearned income	1,294,617	1,491,093
Past due 90 days or more
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing loans past-due 90 days or more	351,614	480,767
Loans held in portfolio, net of unearned income	791,055	1,028,644
Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held in portfolio, net of unearned income	30,783,152	27,749,464
Buy Back Option Program
Accounts, Notes, Loans and Financing Receivable [Line Items]
Repurchased loans	58,000	94,000
GNMA | Trading account debt securities
Accounts, Notes, Loans and Financing Receivable [Line Items]
Transfers Of Financial Assets Accounted For As Sale Initial Fair Value Of Assets Obtained As Proceeds	169,352	380,228
FNMA | Trading account debt securities
Accounts, Notes, Loans and Financing Receivable [Line Items]
Transfers Of Financial Assets Accounted For As Sale Initial Fair Value Of Assets Obtained As Proceeds	122,422	329,617
FHLMC | Trading account debt securities
Accounts, Notes, Loans and Financing Receivable [Line Items]
Transfers Of Financial Assets Accounted For As Sale Initial Fair Value Of Assets Obtained As Proceeds	8,505	22,688
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchase of Loans	433,000	61,000
Residential Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Loans Sold	63,000	145,000
Commercial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchase of Loans	142,000	139,000
Purchased credit deterioration loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchase of Loans	4,000	14,000
Mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchase of Loans	299,000	393,000
Loans held in portfolio, net of unearned income	7,397,471	7,427,196
Non-accrual with no allowance	119,098	169,856
Troubled debt restructurings	1,256,766	1,255,713
Mortgages | Accruing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled debt restructurings	1,169,976	1,143,204
Mortgages | Collateral Pledged
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held in portfolio, net of unearned income	129,173	180,700
Mortgages | Past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held in portfolio, net of unearned income	937,253	1,141,082
Mortgages | Past due 90 days or more
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing loans past-due 90 days or more	337,602	471,358
Loans held in portfolio, net of unearned income	600,481	827,214
Mortgages | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held in portfolio, net of unearned income	6,460,218	6,286,114
Mortgages | US Government Agency Insured Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held in portfolio, net of unearned income	2,000,000	1,900,000
Mortgages | US Government Agency Insured Loans | Past due 90 days or more
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held in portfolio, net of unearned income	300,000	500,000
Mortgages | Guaranteed by U.S. sponsored entities | Accruing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled debt restructurings	725,000	716,000
Mortgages | GNMA | Buy Back Option Program | Past due 90 days or more
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing loans past-due 90 days or more	14,000	13,000
Reverse Mortgages | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held in portfolio, net of unearned income	42,000	50,000
Residential mortgage loans insured By FHA
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual with no allowance	190,000	304,000
Commercial and construction loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans Sold	138,000	131,000
Puerto Rico
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held in portfolio, net of unearned income	22,546,905	20,865,382
Non-accrual with no allowance	170,484	236,748
Puerto Rico | Collateral Pledged
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held in portfolio, net of unearned income	399,047	497,062
Puerto Rico | Past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held in portfolio, net of unearned income	1,213,179	1,418,146
Puerto Rico | Past due 90 days or more
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing loans past-due 90 days or more	351,248	480,649
Loans held in portfolio, net of unearned income	753,257	994,938
Puerto Rico | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held in portfolio, net of unearned income	21,333,726	19,447,236
Puerto Rico | Mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held in portfolio, net of unearned income	6,110,279	6,251,866
Non-accrual with no allowance	119,027	169,827
Puerto Rico | Mortgages | Collateral Pledged
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held in portfolio, net of unearned income	128,069	179,774
Puerto Rico | Mortgages | Past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held in portfolio, net of unearned income	894,800	1,104,829
Puerto Rico | Mortgages | Past due 90 days or more
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accruing loans past-due 90 days or more	337,602	471,358
Loans held in portfolio, net of unearned income	579,993	805,245
Puerto Rico | Mortgages | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held in portfolio, net of unearned income	5,215,479	5,147,037
Puerto Rico | Reverse Mortgages | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held in portfolio, net of unearned income	42,000	50,000
Puerto Rico | Residential mortgage loans insured By FHA | Past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual with no allowance	$ 190,000	$ 304,000