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, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	$ 1,328,161	$ 860,127	$ 1,319,713	$ 839,583
Impaired Financing Receivable Interest Income Accrual Method	7,720	3,708	15,691	7,056
Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	81,275	1,813	79,783	1,209
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
Non Covered Loans [Member] | Commercial Multi Family [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	19,866	18,689	23,685	19,036
Impaired Financing Receivable Interest Income Accrual Method	11	(106)	101	0
Non Covered Loans [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	125,982	130,248	121,936	125,294
Impaired Financing Receivable Interest Income Accrual Method	503	272	1,171	503
Non Covered Loans [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	230,583	206,005	237,362	203,283
Impaired Financing Receivable Interest Income Accrual Method	197	813	773	1,328
Non Covered Loans [Member] | Commercial And Industrial Loans [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	147,161	107,123	151,521	104,956
Impaired Financing Receivable Interest Income Accrual Method	137	506	657	789
Non Covered Loans [Member] | Commercial Real Estate Construction Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	62,578	124,851	72,288	160,341
Impaired Financing Receivable Interest Income Accrual Method	91	0	107	173
Non Covered Loans [Member] | Mortgages
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	480,707	176,390	448,098	157,996
Impaired Financing Receivable Interest Income Accrual Method	6,762	2,223	12,817	4,235
Non Covered Loans [Member] | Legacy [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	38,510	95,008	41,970	67,468
Impaired Financing Receivable Interest Income Accrual Method	19	0	65	28
Non Covered Loans [Member] | Finance Leases Portfolio Segment Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	5,470		5,681
Impaired Financing Receivable Interest Income Accrual Method	0		0
Non Covered Loans [Member] | Consumer Loan [Member] | Consumer Credit Card Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	38,567		38,669
Impaired Financing Receivable Interest Income Accrual Method	0		0
Non Covered Loans [Member] | Consumer Loan [Member] | Home Equity Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	0		0
Impaired Financing Receivable Interest Income Accrual Method	0		0
Non Covered Loans [Member] | Consumer Loan [Member] | Personal [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	90,862		91,828
Impaired Financing Receivable Interest Income Accrual Method	0		0
Non Covered Loans [Member] | Consumer Loan [Member] | Consumer Loans Auto Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	131		119
Impaired Financing Receivable Interest Income Accrual Method	0		0
Non Covered Loans [Member] | Consumer Loan [Member] | Consumer Other Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	6,469		6,773
Impaired Financing Receivable Interest Income Accrual Method	0		0
PUERTO RICO
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	1,087,865	567,779	1,060,797	544,348
Impaired Financing Receivable Interest Income Accrual Method	6,868	3,043	13,697	5,927
PUERTO RICO | Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	81,275	1,813	79,783	1,209
Impaired Financing Receivable Interest Income Accrual Method	0	0	0	0
PUERTO RICO | Non Covered Loans [Member] | Commercial Multi Family [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	8,469	12,409	13,202	13,023
Impaired Financing Receivable Interest Income Accrual Method	0	(106)	0	0
PUERTO RICO | Non Covered Loans [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	61,468	43,652	58,121	36,187
Impaired Financing Receivable Interest Income Accrual Method	176	272	357	389
PUERTO RICO | Non Covered Loans [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	195,838	188,690	198,318	187,388
Impaired Financing Receivable Interest Income Accrual Method	197	459	773	905
PUERTO RICO | Non Covered Loans [Member] | Commercial And Industrial Loans [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	124,604	91,234	124,974	90,918
Impaired Financing Receivable Interest Income Accrual Method	137	326	620	578
PUERTO RICO | Non Covered Loans [Member] | Commercial Real Estate Construction Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	50,013	61,246	49,924	62,730
Impaired Financing Receivable Interest Income Accrual Method	91	0	107	49
PUERTO RICO | Non Covered Loans [Member] | Mortgages
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	427,107	168,735	395,853	152,893
Impaired Financing Receivable Interest Income Accrual Method	6,267	2,092	11,840	4,006
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	5,470		5,681
Impaired Financing Receivable Interest Income Accrual Method	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	38,567		38,669
Impaired Financing Receivable Interest Income Accrual Method	0		0
PUERTO RICO | Non Covered Loans [Member] | Consumer Loan [Member] | Home Equity Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	0		0
Impaired Financing Receivable Interest Income Accrual Method	0		0
PUERTO RICO | Non Covered Loans [Member] | Consumer Loan [Member] | Personal [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	90,862		91,828
Impaired Financing Receivable Interest Income Accrual Method	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	85		57
Impaired Financing Receivable Interest Income Accrual Method	0		0
PUERTO RICO | Non Covered Loans [Member] | Consumer Loan [Member] | Consumer Other Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	4,107		4,387
Impaired Financing Receivable Interest Income Accrual Method	0		0
UNITED STATES
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	240,296	292,348	258,916	295,235
Impaired Financing Receivable Interest Income Accrual Method	852	665	1,994	1,129
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	11,397	6,280	10,483	6,013
Impaired Financing Receivable Interest Income Accrual Method	11	0	101	0
UNITED STATES | Non Covered Loans [Member] | Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	64,514	86,596	63,815	89,107
Impaired Financing Receivable Interest Income Accrual Method	327	0	814	114
UNITED STATES | Non Covered Loans [Member] | Commercial Real Estate Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	34,745	17,315	39,044	15,895
Impaired Financing Receivable Interest Income Accrual Method	0	354	0	423
UNITED STATES | Non Covered Loans [Member] | Commercial And Industrial Loans [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	22,557	15,889	26,547	14,038
Impaired Financing Receivable Interest Income Accrual Method	0	180	37	211
UNITED STATES | Non Covered Loans [Member] | Commercial Real Estate Construction Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	12,565	63,605	22,364	97,611
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	53,600	7,655	52,245	5,103
Impaired Financing Receivable Interest Income Accrual Method	495	131	977	229
UNITED STATES | Non Covered Loans [Member] | Legacy [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	38,510	95,008	41,970	67,468
Impaired Financing Receivable Interest Income Accrual Method	19	0	65	28
UNITED STATES | Non Covered Loans [Member] | Finance Leases Portfolio Segment Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	0		0
Impaired Financing Receivable Interest Income Accrual Method	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
Impaired Financing Receivable Interest Income Accrual Method	0		0
UNITED STATES | Non Covered Loans [Member] | Consumer Loan [Member] | Home Equity Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	0		0
Impaired Financing Receivable Interest Income Accrual Method	0		0
UNITED STATES | Non Covered Loans [Member] | Consumer Loan [Member] | Personal [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	0		0
Impaired Financing Receivable Interest Income Accrual Method	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	46		62
Impaired Financing Receivable Interest Income Accrual Method	0		0
UNITED STATES | Non Covered Loans [Member] | Consumer Loan [Member] | Consumer Other Financing Receivable Member
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	2,362		2,386
Impaired Financing Receivable Interest Income Accrual Method	$ 0		$ 0