Troubled debt restructurings loan count by type of modification (Detail)	3 Months Ended	6 Months Ended
	Jun. 30, 2012 loans	Jun. 30, 2012 loans
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	845	1,852
Extension of Maturity Date	119	240
Combination Interest Rate Reduction Maturity Date Extension	483	845
Other Modifications	399	788
Commercial Multi Family [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0	0
Extension of Maturity Date	0	0
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	0
Commercial Real Estate Non Owner Occupied [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	1	3
Extension of Maturity Date	1	4
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	1
Commercial Real Estate Owner Occupied [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	4	6
Extension of Maturity Date	7	15
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	0
Commercial And Industrial Loans [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	8	25
Extension of Maturity Date	22	53
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	0
Commercial Real Estate Construction Financing Receivable Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0	1
Extension of Maturity Date	0	1
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	1
Mortgages
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	126	164
Extension of Maturity Date	42	83
Combination Interest Rate Reduction Maturity Date Extension	482	842
Other Modifications	65	110
Legacy [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	1	1
Extension of Maturity Date	0	0
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	2
Finance Leases Portfolio Segment Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0	0
Extension of Maturity Date	34	62
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	0
Consumer Credit Card Financing Receivable Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	410	957
Extension of Maturity Date	0	0
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	334	674
Home Equity Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0	0
Extension of Maturity Date	0	0
Combination Interest Rate Reduction Maturity Date Extension	1	1
Other Modifications	0	0
Personal [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	281	670
Extension of Maturity Date	12	21
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	0
Consumer Loans Auto Financing Receivable Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0	0
Extension of Maturity Date	1	1
Combination Interest Rate Reduction Maturity Date Extension	0	2
Other Modifications	0	0
Consumer Other Financing Receivable Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	14	25
Extension of Maturity Date	0	0
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	0
PUERTO RICO
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	842	1,847
Extension of Maturity Date	119	240
Combination Interest Rate Reduction Maturity Date Extension	459	796
Other Modifications	399	784
PUERTO RICO | Commercial Multi Family [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0	0
Extension of Maturity Date	0	0
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	0
PUERTO RICO | Commercial Real Estate Non Owner Occupied [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0	2
Extension of Maturity Date	1	4
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	0
PUERTO RICO | Commercial Real Estate Owner Occupied [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	4	6
Extension of Maturity Date	7	15
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	0
PUERTO RICO | Commercial And Industrial Loans [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	8	25
Extension of Maturity Date	22	53
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	0
PUERTO RICO | Commercial Real Estate Construction Financing Receivable Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0	1
Extension of Maturity Date	0	1
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	0
PUERTO RICO | Mortgages
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	125	161
Extension of Maturity Date	42	83
Combination Interest Rate Reduction Maturity Date Extension	459	794
Other Modifications	65	110
PUERTO RICO | Finance Leases Portfolio Segment Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0	0
Extension of Maturity Date	34	62
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	0
PUERTO RICO | Consumer Credit Card Financing Receivable Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	410	957
Extension of Maturity Date	0	0
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	334	674
PUERTO RICO | Home Equity Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0	0
Extension of Maturity Date	0	0
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	0
PUERTO RICO | Personal [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	281	670
Extension of Maturity Date	12	21
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	0
PUERTO RICO | Consumer Loans Auto Financing Receivable Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0	0
Extension of Maturity Date	1	1
Combination Interest Rate Reduction Maturity Date Extension	0	2
Other Modifications	0	0
PUERTO RICO | Consumer Other Financing Receivable Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	14	25
Extension of Maturity Date	0	0
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	0
UNITED STATES
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	3	5
Extension of Maturity Date	0	0
Combination Interest Rate Reduction Maturity Date Extension	24	49
Other Modifications	0	4
UNITED STATES | Commercial Multi Family [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0	0
Extension of Maturity Date	0	0
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	0
UNITED STATES | Commercial Real Estate Non Owner Occupied [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	1	1
Extension of Maturity Date	0	0
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	1
UNITED STATES | Commercial Real Estate Owner Occupied [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0	0
Extension of Maturity Date	0	0
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	0
UNITED STATES | Commercial And Industrial Loans [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0	0
Extension of Maturity Date	0	0
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	0
UNITED STATES | Commercial Real Estate Construction Financing Receivable Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0	0
Extension of Maturity Date	0	0
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	1
UNITED STATES | Mortgages
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	1	3
Extension of Maturity Date	0	0
Combination Interest Rate Reduction Maturity Date Extension	23	48
Other Modifications	0	0
UNITED STATES | Legacy [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	1	1
Extension of Maturity Date	0	0
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	2
UNITED STATES | Consumer Credit Card Financing Receivable Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0	0
Extension of Maturity Date	0	0
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	0
UNITED STATES | Home Equity Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0	0
Extension of Maturity Date	0	0
Combination Interest Rate Reduction Maturity Date Extension	1	1
Other Modifications	0	0
UNITED STATES | Personal [Member]
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0	0
Extension of Maturity Date	0	0
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	0
UNITED STATES | Consumer Loans Auto Financing Receivable Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0	0
Extension of Maturity Date	0	0
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	0
UNITED STATES | Consumer Other Financing Receivable Member
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
Reduction In Interest Rate	0	0
Extension of Maturity Date	0	0
Combination Interest Rate Reduction Maturity Date Extension	0	0
Other Modifications	0	0