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, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	$ 988,643	$ 1,351,281	$ 1,140,604	$ 1,337,410
Impaired Financing Receivable Interest Income Accrual Method	7,838	10,055	28,118	27,646
Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	30,178	98,603	48,252	89,965
Impaired Financing Receivable Interest Income Accrual Method	410	949	914	2,849
Non Covered Loans [Member] | Commercial Multi Family [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	15,802	22,968	17,043	24,437
Impaired Financing Receivable Interest Income Accrual Method	196	0	366	101
Non Covered Loans [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	88,864	124,900	95,981	122,879
Impaired Financing Receivable Interest Income Accrual Method	508	391	1,035	1,562
Non Covered Loans [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	133,675	220,428	153,845	233,391
Impaired Financing Receivable Interest Income Accrual Method	495	678	1,293	1,451
Non Covered Loans [Member] | Commercial And Industrial Loans [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	98,506	127,834	108,955	144,478
Impaired Financing Receivable Interest Income Accrual Method	784	499	2,485	1,156
Non Covered Loans [Member] | Commercial Real Estate Construction Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	36,435	54,452	41,019	66,191
Impaired Financing Receivable Interest Income Accrual Method	0	98	0	205
Non Covered Loans [Member] | Mortgages [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	439,196	535,550	530,321	476,184
Impaired Financing Receivable Interest Income Accrual Method	5,445	7,426	22,025	20,243
Non Covered Loans [Member] | Legacy [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	12,483	26,783	14,685	37,547
Impaired Financing Receivable Interest Income Accrual Method	0	14	0	79
Non Covered Loans [Member] | Finance Leases Portfolio Segment Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	3,489	5,231	4,054	5,494
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	44,271	38,718	38,801	38,839
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
Non Covered Loans [Member] | Consumer Loan [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	199	101	200	51
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	81,685	91,030	83,740	91,966
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	1,103	344	1,005	195
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	2,757	4,339	2,703	5,793
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
PUERTO RICO
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	852,182	1,151,758	995,340	1,096,793
Impaired Financing Receivable Interest Income Accrual Method	7,192	9,294	26,245	24,891
PUERTO RICO | Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	30,178	98,603	48,252	89,965
Impaired Financing Receivable Interest Income Accrual Method	410	949	914	2,849
PUERTO RICO | Non Covered Loans [Member] | Commercial Multi Family [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	8,262	14,446	9,594	15,083
Impaired Financing Receivable Interest Income Accrual Method	127	0	259	0
PUERTO RICO | Non Covered Loans [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	54,078	64,968	56,875	60,972
Impaired Financing Receivable Interest Income Accrual Method	417	240	853	597
PUERTO RICO | Non Covered Loans [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	114,033	194,126	133,970	197,938
Impaired Financing Receivable Interest Income Accrual Method	495	597	1,194	1,370
PUERTO RICO | Non Covered Loans [Member] | Commercial And Industrial Loans [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	97,629	117,979	106,502	123,062
Impaired Financing Receivable Interest Income Accrual Method	784	499	2,470	1,119
PUERTO RICO | Non Covered Loans [Member] | Commercial Real Estate Construction Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	30,636	42,380	35,159	46,383
Impaired Financing Receivable Interest Income Accrual Method	0	98	0	205
PUERTO RICO | Non Covered Loans [Member] | Mortgages [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	386,359	482,041	477,081	423,571
Impaired Financing Receivable Interest Income Accrual Method	4,959	6,911	20,555	18,751
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	3,489	5,231	4,054	5,494
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	44,271	38,718	38,801	38,839
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
PUERTO RICO | Non Covered Loans [Member] | Consumer Loan [Member] | Home Equity Line of Credit [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	81,685	91,030	83,740	91,966
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	1,014	252	915	126
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	548	1,984	397	3,394
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
UNITED STATES
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	136,461	199,523	145,264	240,617
Impaired Financing Receivable Interest Income Accrual Method	646	761	1,873	2,755
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	7,540	8,522	7,449	9,354
Impaired Financing Receivable Interest Income Accrual Method	69	0	107	101
UNITED STATES | Non Covered Loans [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	34,786	59,932	39,106	61,907
Impaired Financing Receivable Interest Income Accrual Method	91	151	182	965
UNITED STATES | Non Covered Loans [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	19,642	26,302	19,875	35,453
Impaired Financing Receivable Interest Income Accrual Method	0	81	99	81
UNITED STATES | Non Covered Loans [Member] | Commercial And Industrial Loans [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	877	9,855	2,453	21,416
Impaired Financing Receivable Interest Income Accrual Method	0	0	15	37
UNITED STATES | Non Covered Loans [Member] | Commercial Real Estate Construction Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	5,799	12,072	5,860	19,808
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
UNITED STATES | Non Covered Loans [Member] | Mortgages [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	52,837	53,509	53,240	52,613
Impaired Financing Receivable Interest Income Accrual Method	486	515	1,470	1,492
UNITED STATES | Non Covered Loans [Member] | Legacy [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	12,483	26,783	14,685	37,547
Impaired Financing Receivable Interest Income Accrual Method	0	14	0	79
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 Line of Credit [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	199	101	200	51
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	89	92	90	69
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	2,209	2,355	2,306	2,399
Impaired Financing Receivable Interest Income Accrual Method	$ 0	$ 0	$ 0	$ 0