Carrying or notional amounts and estimated fair values for financial instruments (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012		Jun. 30, 2012	Dec. 31, 2011
Assets, Fair Value Disclosure [Abstract]
Cash And Due From Banks	$ 388,041		$ 439,363		$ 515,338	$ 535,282
Money market investments	1,071,939		1,085,580
Marketable Securities, Alternative [Abstract]
Servicing Asset At Fair Value Amount	153,444		154,430		155,711	151,323
Derivative Asset, Fair Value, Gross Asset	37,697		41,925
Deposits, by Type [Abstract]
Time Deposits	8,340,411		8,910,709
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
Securities Sold under Agreements to Repurchase	1,672,705		2,016,752
Notes Payable [Abstract]
Other Notes Payable	23,861		24,208
Fixed Rate 6125 To 8327 Percent Junior Subordinated Deferrable Interest Debentures Due 2027 To 2034 [Member]
Notes Payable [Abstract]
Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust	439,800		439,800
Fixed Rate 500 Percent Until December 2013 And 900 Percent Thereafter Junior Subordinated Deferrable Interest Debentures With No Stated Maturity [Member]
Notes Payable [Abstract]
Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust	516,061	[1]	499,470	[1]
Fair Value, Inputs, Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash And Due From Banks	388,041		439,363
Money market investments	823,586		839,007
Trading account securities	0	[2]	0
Available For Sale Securities Fair Value Disclosure	5,006	[2]	3,827
Held To Maturity Securities Fair Value Disclosure	0		0
Marketable Securities, Alternative [Abstract]
Federal Home Loan Bank Stock	0		0
Federal Reserve Bank Stock	0		0
Trust Preferred Securities	0		0
Other Investments	0		0
Total other investment securities	0		0
Loans held-for-sale	0		0
FDIC loss share asset	0		0
Servicing Asset At Fair Value Amount	0		0
Derivative Asset, Fair Value, Gross Asset	0		0
Deposits, by Type [Abstract]
Demand Deposit Accounts	0		0
Time Deposits	0		0
Deposits	0		0
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
Securities Sold under Agreements to Repurchase	0		0
Assets sold under agreements to repurchase	0		0
Other short-term borrowings	0	[3]	0
Notes Payable [Abstract]
Federal Home Loan Bank Advances Long Term	0		0
Medium-term Notes	0		0
Other Notes Payable	0		0
Notes payable	0		0
Derivative Financial Instruments Liabilities Fair Value Disclosure	0		0
Business Acquisition, Contingent Consideration, at Fair Value	0		0
Fair Value Off Balance Sheet [Abstract]
Commitments to extend credit	0		0
Letters of credit Fair Value Disclosure	0		0
Fair Value, Inputs, Level 1 [Member] | Structured Finance [Member]
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
Securities Sold under Agreements to Repurchase	0		0
Fair Value, Inputs, Level 1 [Member] | Fixed Rate 6125 To 8327 Percent Junior Subordinated Deferrable Interest Debentures Due 2027 To 2034 [Member]
Notes Payable [Abstract]
Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust	0		0
Fair Value, Inputs, Level 1 [Member] | Fixed Rate 500 Percent Until December 2013 And 900 Percent Thereafter Junior Subordinated Deferrable Interest Debentures With No Stated Maturity [Member]
Notes Payable [Abstract]
Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust	0		0
Fair Value, Inputs, Level 1 [Member] | Puerto Rico States And Political Subdivisions Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Held To Maturity Securities Fair Value Disclosure	0		0
Fair Value, Inputs, Level 1 [Member] | Collateralized Mortgage Obligations Issued By U S Government Sponsored Enterprises And U S Government [Member]
Assets, Fair Value Disclosure [Abstract]
Held To Maturity Securities Fair Value Disclosure	0		0
Fair Value, Inputs, Level 1 [Member] | Other Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Held To Maturity Securities Fair Value Disclosure	0		0
Fair Value, Inputs, Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash And Due From Banks	0		0
Money market investments	248,353		246,573
Trading account securities	279,799	[2]	297,959
Available For Sale Securities Fair Value Disclosure	5,102,874	[2]	5,073,304
Held To Maturity Securities Fair Value Disclosure	1,500		1,500
Marketable Securities, Alternative [Abstract]
Federal Home Loan Bank Stock	122,061		89,451
Federal Reserve Bank Stock	80,389		79,878
Trust Preferred Securities	13,197		13,197
Other Investments	0		0
Total other investment securities	215,647		182,526
Loans held-for-sale	8,813		4,779
FDIC loss share asset	0		0
Servicing Asset At Fair Value Amount	0		0
Derivative Asset, Fair Value, Gross Asset	37,950		41,935
Deposits, by Type [Abstract]
Demand Deposit Accounts	18,419,017		18,089,904
Time Deposits	8,406,426		8,994,363
Deposits	26,825,443		27,084,267
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
Securities Sold under Agreements to Repurchase	1,039,293		1,385,237
Assets sold under agreements to repurchase	1,743,375		2,105,857
Other short-term borrowings	1,226,391	[3]	636,200
Notes Payable [Abstract]
Federal Home Loan Bank Advances Long Term	601,390		608,313
Medium-term Notes	244,536		243,351
Other Notes Payable	0		0
Notes payable	1,245,156		1,215,323
Derivative Financial Instruments Liabilities Fair Value Disclosure	33,866		42,585
Business Acquisition, Contingent Consideration, at Fair Value	0		0
Fair Value Off Balance Sheet [Abstract]
Commitments to extend credit	0		0
Letters of credit Fair Value Disclosure	0		0
Fair Value, Inputs, Level 2 [Member] | Structured Finance [Member]
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
Securities Sold under Agreements to Repurchase	704,082		720,620
Fair Value, Inputs, Level 2 [Member] | Fixed Rate 6125 To 8327 Percent Junior Subordinated Deferrable Interest Debentures Due 2027 To 2034 [Member]
Notes Payable [Abstract]
Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust	399,230		363,659
Fair Value, Inputs, Level 2 [Member] | Fixed Rate 500 Percent Until December 2013 And 900 Percent Thereafter Junior Subordinated Deferrable Interest Debentures With No Stated Maturity [Member]
Notes Payable [Abstract]
Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust	0		0
Fair Value, Inputs, Level 2 [Member] | Puerto Rico States And Political Subdivisions Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Held To Maturity Securities Fair Value Disclosure	0		0
Fair Value, Inputs, Level 2 [Member] | Collateralized Mortgage Obligations Issued By U S Government Sponsored Enterprises And U S Government [Member]
Assets, Fair Value Disclosure [Abstract]
Held To Maturity Securities Fair Value Disclosure	0		0
Fair Value, Inputs, Level 2 [Member] | Other Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Held To Maturity Securities Fair Value Disclosure	1,500		1,500
Fair Value, Inputs, Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Cash And Due From Banks	0		0
Money market investments	0		0
Trading account securities	14,030	[2]	16,556
Available For Sale Securities Fair Value Disclosure	6,756	[2]	7,070
Held To Maturity Securities Fair Value Disclosure	142,526		142,733
Marketable Securities, Alternative [Abstract]
Federal Home Loan Bank Stock	0		0
Federal Reserve Bank Stock	0		0
Trust Preferred Securities	1,000		1,000
Other Investments	4,592		3,975
Total other investment securities	5,592		4,975
Loans held-for-sale	186,488		376,582
FDIC loss share asset	1,220,558		1,241,579
Servicing Asset At Fair Value Amount	153,444		154,430
Derivative Asset, Fair Value, Gross Asset	0		0
Deposits, by Type [Abstract]
Demand Deposit Accounts	0		0
Time Deposits	0		0
Deposits	0		0
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
Securities Sold under Agreements to Repurchase	0		0
Assets sold under agreements to repurchase	0		0
Other short-term borrowings	0	[3]	0
Notes Payable [Abstract]
Federal Home Loan Bank Advances Long Term	0		0
Medium-term Notes	730		3,843
Other Notes Payable	23,861		24,208
Notes payable	969,594		852,509
Derivative Financial Instruments Liabilities Fair Value Disclosure	0		0
Business Acquisition, Contingent Consideration, at Fair Value	119,253		112,002
Fair Value Off Balance Sheet [Abstract]
Commitments to extend credit	3,903		2,858
Letters of credit Fair Value Disclosure	1,462		1,544
Fair Value, Inputs, Level 3 [Member] | Structured Finance [Member]
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
Securities Sold under Agreements to Repurchase	0		0
Fair Value, Inputs, Level 3 [Member] | Fixed Rate 6125 To 8327 Percent Junior Subordinated Deferrable Interest Debentures Due 2027 To 2034 [Member]
Notes Payable [Abstract]
Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust	0		0
Fair Value, Inputs, Level 3 [Member] | Fixed Rate 500 Percent Until December 2013 And 900 Percent Thereafter Junior Subordinated Deferrable Interest Debentures With No Stated Maturity [Member]
Notes Payable [Abstract]
Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust	945,003		824,458
Fair Value, Inputs, Level 3 [Member] | Puerto Rico States And Political Subdivisions Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Held To Maturity Securities Fair Value Disclosure	117,399		117,558
Fair Value, Inputs, Level 3 [Member] | Collateralized Mortgage Obligations Issued By U S Government Sponsored Enterprises And U S Government [Member]
Assets, Fair Value Disclosure [Abstract]
Held To Maturity Securities Fair Value Disclosure	128		144
Fair Value, Inputs, Level 3 [Member] | Other Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Held To Maturity Securities Fair Value Disclosure	24,999		25,031
Non Covered Under Loss Sharing Agreements With F D I C [Member] | Fair Value, Inputs, Level 1 [Member]
Marketable Securities, Alternative [Abstract]
Loans held-in-portfolio, net	0		0
Non Covered Under Loss Sharing Agreements With F D I C [Member] | Fair Value, Inputs, Level 2 [Member]
Marketable Securities, Alternative [Abstract]
Loans held-in-portfolio, net	0		0
Non Covered Under Loss Sharing Agreements With F D I C [Member] | Fair Value, Inputs, Level 3 [Member]
Marketable Securities, Alternative [Abstract]
Loans held-in-portfolio, net	18,733,274		17,424,038
Covered Under Loss Sharing Agreements With F D I C [Member] | Fair Value, Inputs, Level 1 [Member]
Marketable Securities, Alternative [Abstract]
Loans held-in-portfolio, net	0		0
Covered Under Loss Sharing Agreements With F D I C [Member] | Fair Value, Inputs, Level 2 [Member]
Marketable Securities, Alternative [Abstract]
Loans held-in-portfolio, net	0		0
Covered Under Loss Sharing Agreements With F D I C [Member] | Fair Value, Inputs, Level 3 [Member]
Marketable Securities, Alternative [Abstract]
Loans held-in-portfolio, net	3,447,478		3,925,440
Carrying (Reported) Amount, Fair Value Disclosure
Assets, Fair Value Disclosure [Abstract]
Cash And Due From Banks	388,041		439,363
Money market investments	1,071,939		1,085,580
Trading account securities	293,829	[2]	314,515	[2]
Available For Sale Securities Fair Value Disclosure	5,114,636	[2]	5,084,201	[2]
Held To Maturity Securities Fair Value Disclosure	141,632		142,817
Marketable Securities, Alternative [Abstract]
Federal Home Loan Bank Stock	122,061		89,451
Federal Reserve Bank Stock	80,389		79,878
Trust Preferred Securities	14,197		14,197
Other Investments	1,935		1,917
Total other investment securities	218,582		185,443
Loans held-for-sale	190,852		354,468
FDIC loss share asset	1,379,342		1,399,098
Servicing Asset At Fair Value Amount	153,444		154,430
Derivative Asset, Fair Value, Gross Asset	37,950		41,935
Deposits, by Type [Abstract]
Demand Deposit Accounts	18,419,017		18,089,904
Time Deposits	8,340,411		8,910,709
Deposits	26,759,428		27,000,613
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
Securities Sold under Agreements to Repurchase	1,034,515		1,378,562
Assets sold under agreements to repurchase	1,672,705		2,016,752
Other short-term borrowings	1,226,200	[3]	636,200	[3]
Notes Payable [Abstract]
Federal Home Loan Bank Advances Long Term	582,364		577,490
Medium-term Notes	233,680		236,753
Other Notes Payable	23,861		24,208
Notes payable	1,795,766		1,777,721
Derivative Financial Instruments Liabilities Fair Value Disclosure	33,866		42,585
Business Acquisition, Contingent Consideration, at Fair Value	119,253		112,002
Carrying (Reported) Amount, Fair Value Disclosure | Structured Finance [Member]
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
Securities Sold under Agreements to Repurchase	638,190		638,190
Carrying (Reported) Amount, Fair Value Disclosure | Fixed Rate 6125 To 8327 Percent Junior Subordinated Deferrable Interest Debentures Due 2027 To 2034 [Member]
Notes Payable [Abstract]
Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust	439,800		439,800
Carrying (Reported) Amount, Fair Value Disclosure | Fixed Rate 500 Percent Until December 2013 And 900 Percent Thereafter Junior Subordinated Deferrable Interest Debentures With No Stated Maturity [Member]
Notes Payable [Abstract]
Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust	516,061		499,470
Carrying (Reported) Amount, Fair Value Disclosure | Puerto Rico States And Political Subdivisions Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Held To Maturity Securities Fair Value Disclosure	115,009		116,177
Carrying (Reported) Amount, Fair Value Disclosure | Collateralized Mortgage Obligations Issued By U S Government Sponsored Enterprises And U S Government [Member]
Assets, Fair Value Disclosure [Abstract]
Held To Maturity Securities Fair Value Disclosure	123		140
Carrying (Reported) Amount, Fair Value Disclosure | Other Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Held To Maturity Securities Fair Value Disclosure	26,500		26,500
Carrying (Reported) Amount, Fair Value Disclosure | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Marketable Securities, Alternative [Abstract]
Loans held-in-portfolio, net	20,992,897		20,361,491
Carrying (Reported) Amount, Fair Value Disclosure | Covered Under Loss Sharing Agreements With F D I C [Member]
Marketable Securities, Alternative [Abstract]
Loans held-in-portfolio, net	3,093,541		3,647,066
Estimate of Fair Value, Fair Value Disclosure
Assets, Fair Value Disclosure [Abstract]
Cash And Due From Banks	388,041		439,363
Money market investments	1,071,939		1,085,580
Trading account securities	293,829	[2]	314,515	[2]
Available For Sale Securities Fair Value Disclosure	5,114,636	[2]	5,084,201	[2]
Held To Maturity Securities Fair Value Disclosure	144,026		144,233
Marketable Securities, Alternative [Abstract]
Federal Home Loan Bank Stock	122,061		89,451
Federal Reserve Bank Stock	80,389		79,878
Trust Preferred Securities	14,197		14,197
Other Investments	4,592		3,975
Total other investment securities	221,239		187,501
Loans held-for-sale	195,301		381,361
FDIC loss share asset	1,220,558		1,241,579
Servicing Asset At Fair Value Amount	153,444		154,430
Derivative Asset, Fair Value, Gross Asset	37,950		41,935
Deposits, by Type [Abstract]
Demand Deposit Accounts	18,419,017		18,089,904
Time Deposits	8,406,426		8,994,363
Deposits	26,825,443		27,084,267
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
Securities Sold under Agreements to Repurchase	1,039,293		1,385,237
Assets sold under agreements to repurchase	1,743,375		2,105,857
Other short-term borrowings	1,226,391	[3]	636,200	[3]
Notes Payable [Abstract]
Federal Home Loan Bank Advances Long Term	601,390		608,313
Medium-term Notes	245,266		247,194
Other Notes Payable	23,861		24,208
Notes payable	2,214,750		2,067,832
Derivative Financial Instruments Liabilities Fair Value Disclosure	33,866		42,585
Business Acquisition, Contingent Consideration, at Fair Value	119,253		112,002
Fair Value Off Balance Sheet [Abstract]
Commitments to extend credit	3,903		2,858
Letters of credit Fair Value Disclosure	1,462		1,544
Estimate of Fair Value, Fair Value Disclosure | Structured Finance [Member]
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
Securities Sold under Agreements to Repurchase	704,082		720,620
Estimate of Fair Value, Fair Value Disclosure | Fixed Rate 6125 To 8327 Percent Junior Subordinated Deferrable Interest Debentures Due 2027 To 2034 [Member]
Notes Payable [Abstract]
Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust	399,230		363,659
Estimate of Fair Value, Fair Value Disclosure | Fixed Rate 500 Percent Until December 2013 And 900 Percent Thereafter Junior Subordinated Deferrable Interest Debentures With No Stated Maturity [Member]
Notes Payable [Abstract]
Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust	945,003		824,458
Estimate of Fair Value, Fair Value Disclosure | Puerto Rico States And Political Subdivisions Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Held To Maturity Securities Fair Value Disclosure	117,399		117,558
Estimate of Fair Value, Fair Value Disclosure | Collateralized Mortgage Obligations Issued By U S Government Sponsored Enterprises And U S Government [Member]
Assets, Fair Value Disclosure [Abstract]
Held To Maturity Securities Fair Value Disclosure	128		144
Estimate of Fair Value, Fair Value Disclosure | Other Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Held To Maturity Securities Fair Value Disclosure	26,499		26,531
Estimate of Fair Value, Fair Value Disclosure | Non Covered Under Loss Sharing Agreements With F D I C [Member]
Marketable Securities, Alternative [Abstract]
Loans held-in-portfolio, net	18,733,274		17,424,038
Estimate of Fair Value, Fair Value Disclosure | Covered Under Loss Sharing Agreements With F D I C [Member]
Marketable Securities, Alternative [Abstract]
Loans held-in-portfolio, net	3,447,478		3,925,440
Notional Amount [Member]
Fair Value Off Balance Sheet [Abstract]
Commitments to extend credit	7,282,621		6,774,990
Letters of credit Fair Value Disclosure	$ 133,387		$ 148,153

[1] The debentures are perpetual and may be redeemed by the Corporation at any time, subject to the consent of the Board of Governors of the Federal Reserve System. The discount on the debentures is being amortized over an estimated 30-year term that started in August 2009. The effective interest rate, including the discount accretion, was approximately 16% at June 30, 2013 and December 31, 2012.

[2] Refer to Note 24 to the consolidated financial statements for the fair value by class of financial asset and its hierarchy level.

[3] Refer to Note 15 to the consolidated financial statements for the composition of short-term borrowings.