Allowance for loan losses ending balance and the loan balance by portfolio segments (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013		Mar. 31, 2013	Dec. 31, 2012
Financing Receivable Allowance For Credit Losses Roll Forward
Allowance for loan losses	$ 640,348		$ 640,555		$ 683,368	$ 730,607
Loans held-in-portfolio:
Non-covered Loans held-in-portfolio	21,611,777	[1]	21,611,866	[1]
Covered Loans	2,870,054		2,984,427
Loans and Leases Receivable Covered And Not Covered Total Net Of Unearned Income	24,481,831		24,596,294
Non Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	115,136		103,506
Ending balance: loans collectively evaluated for impairment	427,439		434,957
Allowance for loan losses	542,575		538,463
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	946,500		908,716
Ending balance: loans collectively evaluated for impairment	20,665,277		20,703,151
Non-covered Loans held-in-portfolio	21,611,777		21,611,867
Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	0		293
Ending balance: loans collectively evaluated for impairment	97,773		101,799
Allowance for loan losses	97,773		102,092
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	5,540		20,945
Ending balance: loans collectively evaluated for impairment	2,864,514		2,963,482
Covered Loans	2,870,054		2,984,427
PUERTO RICO
Financing Receivable Allowance For Credit Losses Roll Forward
Allowance for loan losses	532,513		528,867
Loans held-in-portfolio:
Non-covered Loans held-in-portfolio	15,962,919	[2]	15,887,839	[2]
Loans and Leases Receivable Covered And Not Covered Total Net Of Unearned Income	18,832,973		18,872,266
PUERTO RICO | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	97,299		85,593
Ending balance: loans collectively evaluated for impairment	337,441		341,182
Allowance for loan losses	434,740		426,775		424,021	445,297
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	857,341		789,785
Ending balance: loans collectively evaluated for impairment	15,105,578		15,098,054
Non-covered Loans held-in-portfolio	15,962,919		15,887,839
PUERTO RICO | Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	0		293
Ending balance: loans collectively evaluated for impairment	97,773		101,799
Allowance for loan losses	97,773		102,092		99,867	108,906
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	5,540		20,945
Ending balance: loans collectively evaluated for impairment	2,864,514		2,963,482
Covered Loans	2,870,054		2,984,427
UNITED STATES
Loans held-in-portfolio:
Non-covered Loans held-in-portfolio	5,648,858		5,724,027
UNITED STATES | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	17,837		17,913
Ending balance: loans collectively evaluated for impairment	89,998		93,775
Allowance for loan losses	107,835		111,688		159,480	176,404
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	89,159		118,931
Ending balance: loans collectively evaluated for impairment	5,559,699		5,605,097
Non-covered Loans held-in-portfolio	5,648,858		5,724,028
Commercial Portfolio Segment Member
Financing Receivable Allowance For Credit Losses Roll Forward
Allowance for loan losses	210,603		217,180		296,551	369,742
Loans held-in-portfolio:
Non-covered Loans held-in-portfolio	10,014,721		10,037,184
Loans and Leases Receivable Covered And Not Covered Total Net Of Unearned Income	11,806,406		11,849,989
Commercial Portfolio Segment Member | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	30,892		16,409
Ending balance: loans collectively evaluated for impairment	141,122		158,573
Allowance for loan losses	172,014		174,982
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	334,975		297,516
Ending balance: loans collectively evaluated for impairment	9,679,746		9,739,669
Non-covered Loans held-in-portfolio	10,014,721		10,037,185
Commercial Portfolio Segment Member | Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	0		153
Ending balance: loans collectively evaluated for impairment	38,589		42,045
Allowance for loan losses	38,589		42,198
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	5,540		20,945
Ending balance: loans collectively evaluated for impairment	1,786,145		1,791,859
Covered Loans	1,791,685		1,812,804
Commercial Portfolio Segment Member | PUERTO RICO
Financing Receivable Allowance For Credit Losses Roll Forward
Allowance for loan losses	162,723		170,348
Loans held-in-portfolio:
Non-covered Loans held-in-portfolio	6,442,998	[2]	6,465,590	[2]
Loans and Leases Receivable Covered And Not Covered Total Net Of Unearned Income	8,234,683		8,278,394
Commercial Portfolio Segment Member | PUERTO RICO | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	30,892		16,409
Ending balance: loans collectively evaluated for impairment	93,242		111,741
Allowance for loan losses	124,134		128,150		160,883	217,615
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	304,531		245,380
Ending balance: loans collectively evaluated for impairment	6,138,467		6,220,210
Non-covered Loans held-in-portfolio	6,442,998		6,465,590
Commercial Portfolio Segment Member | PUERTO RICO | Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	0		153
Ending balance: loans collectively evaluated for impairment	38,589		42,045
Allowance for loan losses	38,589		42,198		67,681	72,060
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	5,540		20,945
Ending balance: loans collectively evaluated for impairment	1,786,145		1,791,859
Covered Loans	1,791,685		1,812,804
Commercial Portfolio Segment Member | UNITED STATES
Loans held-in-portfolio:
Non-covered Loans held-in-portfolio	3,571,723		3,571,594
Commercial Portfolio Segment Member | UNITED STATES | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	0		0
Ending balance: loans collectively evaluated for impairment	47,880		46,832
Allowance for loan losses	47,880		46,832		67,987	80,067
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	30,444		52,136
Ending balance: loans collectively evaluated for impairment	3,541,279		3,519,459
Non-covered Loans held-in-portfolio	3,571,723		3,571,595
Commercial Real Estate Construction Financing Receivable Member
Financing Receivable Allowance For Credit Losses Roll Forward
Allowance for loan losses	21,268		24,833		13,732	17,375
Loans held-in-portfolio:
Non-covered Loans held-in-portfolio	176,766		206,084
Covered Loans	127,444		190,127
Loans and Leases Receivable Covered And Not Covered Total Net Of Unearned Income	304,210		396,211
Commercial Real Estate Construction Financing Receivable Member | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	243		177
Ending balance: loans collectively evaluated for impairment	5,059		5,165
Allowance for loan losses	5,302		5,342
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	22,011		22,486
Ending balance: loans collectively evaluated for impairment	154,755		183,598
Non-covered Loans held-in-portfolio	176,766		206,084
Commercial Real Estate Construction Financing Receivable Member | Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	0		140
Ending balance: loans collectively evaluated for impairment	15,966		19,351
Allowance for loan losses	15,966		19,491
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	0		0
Ending balance: loans collectively evaluated for impairment	127,444		190,127
Covered Loans	127,444		190,127
Commercial Real Estate Construction Financing Receivable Member | PUERTO RICO
Financing Receivable Allowance For Credit Losses Roll Forward
Allowance for loan losses	21,045		24,586
Loans held-in-portfolio:
Non-covered Loans held-in-portfolio	141,603	[2]	161,171	[2]
Loans and Leases Receivable Covered And Not Covered Total Net Of Unearned Income	269,047		351,298
Commercial Real Estate Construction Financing Receivable Member | PUERTO RICO | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	243		177
Ending balance: loans collectively evaluated for impairment	4,836		4,918
Allowance for loan losses	5,079		5,095		6,403	5,862
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	22,011		16,823
Ending balance: loans collectively evaluated for impairment	119,592		144,348
Non-covered Loans held-in-portfolio	141,603		161,171
Commercial Real Estate Construction Financing Receivable Member | PUERTO RICO | Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	0		140
Ending balance: loans collectively evaluated for impairment	15,966		19,351
Allowance for loan losses	15,966		19,491		6,293	9,946
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	0		0
Ending balance: loans collectively evaluated for impairment	127,444		190,127
Covered Loans	127,444		190,127
Commercial Real Estate Construction Financing Receivable Member | UNITED STATES
Loans held-in-portfolio:
Non-covered Loans held-in-portfolio	35,163		44,913
Commercial Real Estate Construction Financing Receivable Member | UNITED STATES | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	0		0
Ending balance: loans collectively evaluated for impairment	223		247
Allowance for loan losses	223		247		1,036	1,567
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	0		5,663
Ending balance: loans collectively evaluated for impairment	35,163		39,250
Non-covered Loans held-in-portfolio	35,163		44,913
Mortgages [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Allowance for loan losses	201,811		192,935		182,618	170,289
Loans held-in-portfolio:
Non-covered Loans held-in-portfolio	6,669,376		6,681,476
Covered Loans	907,069		934,373
Loans and Leases Receivable Covered And Not Covered Total Net Of Unearned Income	7,576,445		7,615,849
Mortgages [Member] | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	53,916		55,667
Ending balance: loans collectively evaluated for impairment	109,047		101,262
Allowance for loan losses	162,963		156,929
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	458,513		452,073
Ending balance: loans collectively evaluated for impairment	6,210,863		6,229,403
Non-covered Loans held-in-portfolio	6,669,376		6,681,476
Mortgages [Member] | Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	0		0
Ending balance: loans collectively evaluated for impairment	38,848		36,006
Allowance for loan losses	38,848		36,006
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	0		0
Ending balance: loans collectively evaluated for impairment	907,069		934,373
Covered Loans	907,069		934,373
Mortgages [Member] | PUERTO RICO
Financing Receivable Allowance For Credit Losses Roll Forward
Allowance for loan losses	176,644		166,336
Loans held-in-portfolio:
Non-covered Loans held-in-portfolio	5,424,861	[2]	5,400,679	[2]
Loans and Leases Receivable Covered And Not Covered Total Net Of Unearned Income	6,331,930		6,335,052
Mortgages [Member] | PUERTO RICO | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	36,322		38,034
Ending balance: loans collectively evaluated for impairment	101,474		92,296
Allowance for loan losses	137,796		130,330		130,466	119,027
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	406,053		399,347
Ending balance: loans collectively evaluated for impairment	5,018,808		5,001,332
Non-covered Loans held-in-portfolio	5,424,861		5,400,679
Mortgages [Member] | PUERTO RICO | Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	0		0
Ending balance: loans collectively evaluated for impairment	38,848		36,006
Allowance for loan losses	38,848		36,006		20,673	20,914
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	0		0
Ending balance: loans collectively evaluated for impairment	907,069		934,373
Covered Loans	907,069		934,373
Mortgages [Member] | UNITED STATES
Loans held-in-portfolio:
Non-covered Loans held-in-portfolio	1,244,515		1,280,797
Mortgages [Member] | UNITED STATES | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	17,594		17,633
Ending balance: loans collectively evaluated for impairment	7,573		8,966
Allowance for loan losses	25,167		26,599		31,479	30,348
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	52,460		52,726
Ending balance: loans collectively evaluated for impairment	1,192,055		1,228,071
Non-covered Loans held-in-portfolio	1,244,515		1,280,797
Legacy [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Allowance for loan losses	13,272		13,704		30,777	33,102
Loans held-in-portfolio:
Non-covered Loans held-in-portfolio	197,164	[3]	211,135	[3]
Loans and Leases Receivable Covered And Not Covered Total Net Of Unearned Income	197,164		211,135
Legacy [Member] | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	0		0
Ending balance: loans collectively evaluated for impairment	13,272		13,704
Allowance for loan losses	13,272		13,704
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	3,710		6,045
Ending balance: loans collectively evaluated for impairment	193,454		205,090
Non-covered Loans held-in-portfolio	197,164		211,135
Legacy [Member] | Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	0		0
Ending balance: loans collectively evaluated for impairment	0		0
Allowance for loan losses	0		0
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	0		0
Ending balance: loans collectively evaluated for impairment	0		0
Covered Loans	0		0
Legacy [Member] | UNITED STATES
Loans held-in-portfolio:
Non-covered Loans held-in-portfolio	197,164		211,135
Legacy [Member] | UNITED STATES | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	0		0
Ending balance: loans collectively evaluated for impairment	13,272		13,704
Allowance for loan losses	13,272		13,704		30,777	33,102
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	3,710		6,045
Ending balance: loans collectively evaluated for impairment	193,454		205,090
Non-covered Loans held-in-portfolio	197,164		211,135
Finance Leases Portfolio Segment Member
Financing Receivable Allowance For Credit Losses Roll Forward
Allowance for loan losses	10,483		10,622		3,895	2,894
Loans held-in-portfolio:
Non-covered Loans held-in-portfolio	546,880		543,761
Loans and Leases Receivable Covered And Not Covered Total Net Of Unearned Income	546,880		543,761
Finance Leases Portfolio Segment Member | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	672		1,053
Ending balance: loans collectively evaluated for impairment	9,811		9,569
Allowance for loan losses	10,483		10,622
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	2,455		2,893
Ending balance: loans collectively evaluated for impairment	544,425		540,868
Non-covered Loans held-in-portfolio	546,880		543,761
Finance Leases Portfolio Segment Member | Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	0		0
Ending balance: loans collectively evaluated for impairment	0		0
Allowance for loan losses	0		0
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	0		0
Ending balance: loans collectively evaluated for impairment	0		0
Covered Loans	0		0
Finance Leases Portfolio Segment Member | PUERTO RICO
Financing Receivable Allowance For Credit Losses Roll Forward
Allowance for loan losses	10,483		10,622
Loans held-in-portfolio:
Non-covered Loans held-in-portfolio	546,880	[2]	543,761	[2]
Loans and Leases Receivable Covered And Not Covered Total Net Of Unearned Income	546,880		543,761
Finance Leases Portfolio Segment Member | PUERTO RICO | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	672		1,053
Ending balance: loans collectively evaluated for impairment	9,811		9,569
Allowance for loan losses	10,483		10,622		3,895	2,894
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	2,455		2,893
Ending balance: loans collectively evaluated for impairment	544,425		540,868
Non-covered Loans held-in-portfolio	546,880		543,761
Finance Leases Portfolio Segment Member | PUERTO RICO | Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	0		0
Ending balance: loans collectively evaluated for impairment	0		0
Allowance for loan losses	0		0		0	0
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	0		0
Ending balance: loans collectively evaluated for impairment	0		0
Covered Loans	0		0
Consumer [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Allowance for loan losses	182,911		181,281		155,795	137,205
Loans held-in-portfolio:
Non-covered Loans held-in-portfolio	4,006,870		3,932,226
Covered Loans	43,856		47,123
Loans and Leases Receivable Covered And Not Covered Total Net Of Unearned Income	4,050,726		3,979,349
Consumer [Member] | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	29,413		30,200
Ending balance: loans collectively evaluated for impairment	149,128		146,684
Allowance for loan losses	178,541		176,884
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	124,836		127,703
Ending balance: loans collectively evaluated for impairment	3,882,034		3,804,523
Non-covered Loans held-in-portfolio	4,006,870		3,932,226
Consumer [Member] | Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	0		0
Ending balance: loans collectively evaluated for impairment	4,370		4,397
Allowance for loan losses	4,370		4,397
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	0		0
Ending balance: loans collectively evaluated for impairment	43,856		47,123
Covered Loans	43,856		47,123
Consumer [Member] | PUERTO RICO
Financing Receivable Allowance For Credit Losses Roll Forward
Allowance for loan losses	161,618		156,975
Loans held-in-portfolio:
Non-covered Loans held-in-portfolio	3,406,577	[2]	3,316,638	[2]
Loans and Leases Receivable Covered And Not Covered Total Net Of Unearned Income	3,450,433		3,363,761
Consumer [Member] | PUERTO RICO | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	29,170		29,920
Ending balance: loans collectively evaluated for impairment	128,078		122,658
Allowance for loan losses	157,248		152,578		122,374	99,899
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	122,291		125,342
Ending balance: loans collectively evaluated for impairment	3,284,286		3,191,296
Non-covered Loans held-in-portfolio	3,406,577		3,316,638
Consumer [Member] | PUERTO RICO | Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	0		0
Ending balance: loans collectively evaluated for impairment	4,370		4,397
Allowance for loan losses	4,370		4,397		5,220	5,986
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	0		0
Ending balance: loans collectively evaluated for impairment	43,856		47,123
Covered Loans	43,856		47,123
Consumer [Member] | UNITED STATES
Loans held-in-portfolio:
Non-covered Loans held-in-portfolio	600,293		615,588
Consumer [Member] | UNITED STATES | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Financing Receivable Allowance For Credit Losses Roll Forward
Ending balance: loans individually evaluated for impairment	243		280
Ending balance: loans collectively evaluated for impairment	21,050		24,026
Allowance for loan losses	21,293		24,306		28,201	31,320
Loans held-in-portfolio:
Ending balance: loans individually evaluated for impairment	2,545		2,361
Ending balance: loans collectively evaluated for impairment	597,748		613,227
Non-covered Loans held-in-portfolio	$ 600,293		$ 615,588

[1] Non-covered loans held-in-portfolio at March 31, 2014 are net of $91 million in unearned income and exclude $95 million in loans held-for-sale. (December 31, 2013 - $92 million in unearned income and $110 million in loans held-for-sale.)

[2] Excludes covered loans acquired in the Westernbank FDIC-assisted transaction.

[3] The legacy portfolio is comprised of commercial loans, construction loans and lease financings related to certain lending products exited by the Corporation as part of restructuring efforts carried out in prior years at the BPNA segment.