Average recorded investment and interest income recognized on impaired loans (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	$ 1,351,281	$ 1,033,039	$ 1,337,410	$ 922,381
Impaired Financing Receivable Interest Income Accrual Method	10,055	4,957	27,646	12,013
Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	98,603	3,151	89,965	1,575
Impaired Financing Receivable Interest Income Accrual Method	949	76	2,849	76
Non Covered Loans [Member] | Commercial Multi Family [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	22,968	13,748	24,437	17,236
Impaired Financing Receivable Interest Income Accrual Method	0	0	101	0
Non Covered Loans [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	124,900	129,411	122,879	124,769
Impaired Financing Receivable Interest Income Accrual Method	391	354	1,562	1,078
Non Covered Loans [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	220,428	216,408	233,391	207,453
Impaired Financing Receivable Interest Income Accrual Method	678	717	1,451	1,820
Non Covered Loans [Member] | Commercial And Industrial Loans [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	127,834	128,542	144,478	115,261
Impaired Financing Receivable Interest Income Accrual Method	499	291	1,156	1,080
Non Covered Loans [Member] | Commercial Real Estate Construction Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	54,452	122,051	66,191	150,062
Impaired Financing Receivable Interest Income Accrual Method	98	0	205	173
Non Covered Loans [Member] | Mortgages
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	535,550	259,852	476,184	196,985
Impaired Financing Receivable Interest Income Accrual Method	7,426	3,365	20,243	7,600
Non Covered Loans [Member] | Legacy [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	26,783	83,065	37,547	70,634
Impaired Financing Receivable Interest Income Accrual Method	14	154	79	186
Non Covered Loans [Member] | Finance Leases Portfolio Segment Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	5,231	3,284	5,494	1,642
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
Non Covered Loans [Member] | Consumer Loan [Member] | Consumer Credit Card Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	38,718	20,622	38,839	10,311
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
Non Covered Loans [Member] | Consumer Loan [Member] | Home Equity Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	101	947	51	473
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
Non Covered Loans [Member] | Consumer Loan [Member] | Personal [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	91,030	50,282	91,966	25,141
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
Non Covered Loans [Member] | Consumer Loan [Member] | Consumer Loans Auto Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	344	32	195	16
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
Non Covered Loans [Member] | Consumer Loan [Member] | Consumer Other Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	4,339	1,644	5,793	823
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
PUERTO RICO
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	1,151,758	743,035	1,096,793	626,765
Impaired Financing Receivable Interest Income Accrual Method	9,294	4,315	24,891	10,242
PUERTO RICO | Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	98,603	3,151	89,965	1,575
Impaired Financing Receivable Interest Income Accrual Method	949	76	2,849	76
PUERTO RICO | Non Covered Loans [Member] | Commercial Multi Family [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	14,446	9,399	15,083	12,071
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
PUERTO RICO | Non Covered Loans [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	64,968	50,687	60,972	39,115
Impaired Financing Receivable Interest Income Accrual Method	240	283	597	672
PUERTO RICO | Non Covered Loans [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	194,126	193,918	197,938	188,945
Impaired Financing Receivable Interest Income Accrual Method	597	694	1,370	1,599
PUERTO RICO | Non Covered Loans [Member] | Commercial And Industrial Loans [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	117,979	108,533	123,062	100,052
Impaired Financing Receivable Interest Income Accrual Method	499	288	1,119	866
PUERTO RICO | Non Covered Loans [Member] | Commercial Real Estate Construction Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	42,380	63,818	46,383	62,485
Impaired Financing Receivable Interest Income Accrual Method	98	0	205	49
PUERTO RICO | Non Covered Loans [Member] | Mortgages
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	482,041	239,026	423,571	185,270
Impaired Financing Receivable Interest Income Accrual Method	6,911	2,974	18,751	6,980
PUERTO RICO | Non Covered Loans [Member] | Legacy [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	0	0	0	0
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
PUERTO RICO | Non Covered Loans [Member] | Finance Leases Portfolio Segment Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	5,231	3,284	5,494	1,642
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
PUERTO RICO | Non Covered Loans [Member] | Consumer Loan [Member] | Consumer Credit Card Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	38,718	20,622	38,839	10,311
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
PUERTO RICO | Non Covered Loans [Member] | Consumer Loan [Member] | Home Equity Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	0	0	0	0
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
PUERTO RICO | Non Covered Loans [Member] | Consumer Loan [Member] | Personal [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	91,030	50,282	91,966	25,141
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
PUERTO RICO | Non Covered Loans [Member] | Consumer Loan [Member] | Consumer Loans Auto Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	252	32	126	16
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
PUERTO RICO | Non Covered Loans [Member] | Consumer Loan [Member] | Consumer Other Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	1,984	283	3,394	142
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
UNITED STATES
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	199,523	290,004	240,617	295,616
Impaired Financing Receivable Interest Income Accrual Method	761	642	2,755	1,771
UNITED STATES | Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	0	0	0	0
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
UNITED STATES | Non Covered Loans [Member] | Commercial Multi Family [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	8,522	4,349	9,354	5,165
Impaired Financing Receivable Interest Income Accrual Method	0	0	101	0
UNITED STATES | Non Covered Loans [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	59,932	78,724	61,907	85,654
Impaired Financing Receivable Interest Income Accrual Method	151	71	965	406
UNITED STATES | Non Covered Loans [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	26,302	22,490	35,453	18,508
Impaired Financing Receivable Interest Income Accrual Method	81	23	81	221
UNITED STATES | Non Covered Loans [Member] | Commercial And Industrial Loans [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	9,855	20,009	21,416	15,209
Impaired Financing Receivable Interest Income Accrual Method	0	3	37	214
UNITED STATES | Non Covered Loans [Member] | Commercial Real Estate Construction Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	12,072	58,233	19,808	87,577
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	124
UNITED STATES | Non Covered Loans [Member] | Mortgages
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	53,509	20,826	52,613	11,715
Impaired Financing Receivable Interest Income Accrual Method	515	391	1,492	620
UNITED STATES | Non Covered Loans [Member] | Legacy [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	26,783	83,065	37,547	70,634
Impaired Financing Receivable Interest Income Accrual Method	14	154	79	186
UNITED STATES | Non Covered Loans [Member] | Finance Leases Portfolio Segment Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	0	0	0	0
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
UNITED STATES | Non Covered Loans [Member] | Consumer Loan [Member] | Consumer Credit Card Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	0	0	0	0
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
UNITED STATES | Non Covered Loans [Member] | Consumer Loan [Member] | Home Equity Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	101	947	51	473
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
UNITED STATES | Non Covered Loans [Member] | Consumer Loan [Member] | Personal [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	0	0	0	0
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
UNITED STATES | Non Covered Loans [Member] | Consumer Loan [Member] | Consumer Loans Auto Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	92	0	69	0
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
UNITED STATES | Non Covered Loans [Member] | Consumer Loan [Member] | Consumer Other Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	2,355	1,361	2,399	681
Impaired Financing Receivable Interest Income Accrual Method	$ 0	$ 0	$ 0	$ 0