Average recorded investment and interest income recognized on impaired loans (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	$ 1,063,048	$ 1,328,161	$ 1,191,009	$ 1,319,713
Impaired Financing Receivable Interest Income Accrual Method	10,333	7,720	20,701	15,691
Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	24,252	81,275	52,582	79,783
Impaired Financing Receivable Interest Income Accrual Method	265	0	504	0
Non Covered Loans [Member] | Commercial Multi Family [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	15,067	19,866	17,042	23,685
Impaired Financing Receivable Interest Income Accrual Method	(29)	11	171	101
Non Covered Loans [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	86,130	125,982	98,575	121,936
Impaired Financing Receivable Interest Income Accrual Method	419	503	813	1,171
Non Covered Loans [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	119,127	230,583	160,261	237,362
Impaired Financing Receivable Interest Income Accrual Method	566	197	1,024	773
Non Covered Loans [Member] | Commercial And Industrial Loans [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	98,079	147,161	112,276	151,521
Impaired Financing Receivable Interest Income Accrual Method	769	137	1,608	657
Non Covered Loans [Member] | Commercial Real Estate Construction Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	47,387	62,578	45,528	72,288
Impaired Financing Receivable Interest Income Accrual Method	0	91	0	107
Non Covered Loans [Member] | Mortgages
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	533,435	480,707	559,366	448,098
Impaired Financing Receivable Interest Income Accrual Method	8,343	6,762	16,581	12,817
Non Covered Loans [Member] | Legacy [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	14,200	38,510	15,714	41,970
Impaired Financing Receivable Interest Income Accrual Method	0	19	0	65
Non Covered Loans [Member] | Finance Leases Portfolio Segment Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	4,088	5,470	4,352	5,681
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	34,019	38,567	36,851	38,669
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	200	0	200	0
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	83,531	90,862	84,648	91,828
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	948	131	919	119
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	2,585	6,469	2,695	6,773
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
PUERTO RICO
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	920,568	1,087,865	1,042,226	1,060,797
Impaired Financing Receivable Interest Income Accrual Method	9,723	6,868	19,572	13,697
PUERTO RICO | Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	24,252	81,275	52,582	79,783
Impaired Financing Receivable Interest Income Accrual Method	265	0	504	0
PUERTO RICO | Non Covered Loans [Member] | Commercial Multi Family [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	8,448	8,469	10,082	13,202
Impaired Financing Receivable Interest Income Accrual Method	(29)	0	132	0
PUERTO RICO | Non Covered Loans [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	47,621	61,468	57,631	58,121
Impaired Financing Receivable Interest Income Accrual Method	364	176	723	357
PUERTO RICO | Non Covered Loans [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	98,892	195,838	139,981	198,318
Impaired Financing Receivable Interest Income Accrual Method	493	197	1,009	773
PUERTO RICO | Non Covered Loans [Member] | Commercial And Industrial Loans [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	96,622	124,604	109,286	124,974
Impaired Financing Receivable Interest Income Accrual Method	769	137	1,608	620
PUERTO RICO | Non Covered Loans [Member] | Commercial Real Estate Construction Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	41,528	50,013	39,635	49,924
Impaired Financing Receivable Interest Income Accrual Method	0	91	0	107
PUERTO RICO | Non Covered Loans [Member] | Mortgages
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	480,435	427,107	506,002	395,853
Impaired Financing Receivable Interest Income Accrual Method	7,861	6,267	15,596	11,840
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	4,088	5,470	4,352	5,681
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	34,019	38,567	36,851	38,669
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	83,531	90,862	84,648	91,828
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	858	85	829	57
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	274	4,107	347	4,387
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
UNITED STATES
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	142,480	240,296	148,783	258,916
Impaired Financing Receivable Interest Income Accrual Method	610	852	1,129	1,994
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	6,619	11,397	6,960	10,483
Impaired Financing Receivable Interest Income Accrual Method	0	11	39	101
UNITED STATES | Non Covered Loans [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	38,509	64,514	40,944	63,815
Impaired Financing Receivable Interest Income Accrual Method	55	327	90	814
UNITED STATES | Non Covered Loans [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	20,235	34,745	20,280	39,044
Impaired Financing Receivable Interest Income Accrual Method	73	0	15	0
UNITED STATES | Non Covered Loans [Member] | Commercial And Industrial Loans [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	1,457	22,557	2,990	26,547
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	37
UNITED STATES | Non Covered Loans [Member] | Commercial Real Estate Construction Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	5,859	12,565	5,893	22,364
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
UNITED STATES | Non Covered Loans [Member] | Mortgages
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	53,000	53,600	53,364	52,245
Impaired Financing Receivable Interest Income Accrual Method	482	495	985	977
UNITED STATES | Non Covered Loans [Member] | Legacy [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	14,200	38,510	15,714	41,970
Impaired Financing Receivable Interest Income Accrual Method	0	19	0	65
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	200	0	200	0
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	90	46	90	62
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	2,311	2,362	2,348	2,386
Impaired Financing Receivable Interest Income Accrual Method	$ 0	$ 0	$ 0	$ 0