Troubled debt restructurings loan count by type of modification (Detail)	3 Months Ended
	Mar. 31, 2012 loans
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	1,005
Extension of Maturity Date	121
Combination Interest Rate Reduction Maturity Date Extension	362
Other Modifications	389
Commercial Multi Family [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0
Extension of Maturity Date	0
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	0
Commercial Real Estate Non Owner Occupied [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	1
Extension of Maturity Date	3
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	1
Commercial Real Estate Owner Occupied [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	2
Extension of Maturity Date	8
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	0
Commercial And Industrial Loans [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	17
Extension of Maturity Date	31
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	0
Commercial Real Estate Construction Financing Receivable Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	1
Extension of Maturity Date	1
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	1
Mortgages
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	38
Extension of Maturity Date	41
Combination Interest Rate Reduction Maturity Date Extension	360
Other Modifications	45
Legacy [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0
Extension of Maturity Date	0
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	2
Finance Leases Portfolio Segment Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0
Extension of Maturity Date	28
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	0
Consumer Credit Card Financing Receivable Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	547
Extension of Maturity Date	0
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	340
Home Equity Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0
Extension of Maturity Date	0
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	0
Personal [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	388
Extension of Maturity Date	9
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	0
Consumer Loans Auto Financing Receivable Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0
Extension of Maturity Date	0
Combination Interest Rate Reduction Maturity Date Extension	2
Other Modifications	0
Consumer Other Financing Receivable Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	11
Extension of Maturity Date	0
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	0
PUERTO RICO
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	1,003
Extension of Maturity Date	121
Combination Interest Rate Reduction Maturity Date Extension	337
Other Modifications	385
PUERTO RICO | Commercial Multi Family [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0
Extension of Maturity Date	0
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	0
PUERTO RICO | Commercial Real Estate Non Owner Occupied [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	1
Extension of Maturity Date	3
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	0
PUERTO RICO | Commercial Real Estate Owner Occupied [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	2
Extension of Maturity Date	8
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	0
PUERTO RICO | Commercial And Industrial Loans [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	17
Extension of Maturity Date	31
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	0
PUERTO RICO | Commercial Real Estate Construction Financing Receivable Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	1
Extension of Maturity Date	1
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	0
PUERTO RICO | Mortgages
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	36
Extension of Maturity Date	41
Combination Interest Rate Reduction Maturity Date Extension	335
Other Modifications	45
PUERTO RICO | Finance Leases Portfolio Segment Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0
Extension of Maturity Date	28
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	0
PUERTO RICO | Consumer Credit Card Financing Receivable Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	547
Extension of Maturity Date	0
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	340
PUERTO RICO | Home Equity Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	0
PUERTO RICO | Personal [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	388
Extension of Maturity Date	9
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	0
PUERTO RICO | Consumer Loans Auto Financing Receivable Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0
Extension of Maturity Date	0
Combination Interest Rate Reduction Maturity Date Extension	2
Other Modifications	0
PUERTO RICO | Consumer Other Financing Receivable Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	11
Extension of Maturity Date	0
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	0
UNITED STATES
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	2
Extension of Maturity Date	0
Combination Interest Rate Reduction Maturity Date Extension	25
Other Modifications	4
UNITED STATES | Commercial Multi Family [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0
Extension of Maturity Date	0
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	0
UNITED STATES | Commercial Real Estate Non Owner Occupied [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0
Extension of Maturity Date	0
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	1
UNITED STATES | Commercial Real Estate Owner Occupied [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0
Extension of Maturity Date	0
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	0
UNITED STATES | Commercial And Industrial Loans [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0
Extension of Maturity Date	0
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	0
UNITED STATES | Commercial Real Estate Construction Financing Receivable Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0
Extension of Maturity Date	0
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	1
UNITED STATES | Mortgages
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	2
Extension of Maturity Date	0
Combination Interest Rate Reduction Maturity Date Extension	25
Other Modifications	0
UNITED STATES | Legacy [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0
Extension of Maturity Date	0
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	2
UNITED STATES | Consumer Credit Card Financing Receivable Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0
Extension of Maturity Date	0
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	0
UNITED STATES | Home Equity Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0
Extension of Maturity Date	0
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	0
UNITED STATES | Personal [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0
Extension of Maturity Date	0
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	0
UNITED STATES | Consumer Loans Auto Financing Receivable Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0
Extension of Maturity Date	0
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	0
UNITED STATES | Consumer Other Financing Receivable Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0
Extension of Maturity Date	0
Combination Interest Rate Reduction Maturity Date Extension	0
Other Modifications	0