Note Fair value of financial instruments (Carrying or notional amounts and estimated fair values for financial instruments) (Detail) - USD ($) $ in Thousands		Mar. 31, 2017		Dec. 31, 2016		Mar. 31, 2016	Dec. 31, 2015
Financial Assets:
Cash And Due From Banks		$ 340,225		$ 362,394
Money market investments		3,653,347		2,890,217
Trading account securities, excluding derivatives		50,985		59,805
Available For Sale Securities		9,197,527	[1]	8,209,806	[2]
Investment securities held-to-maturity, at amortized cost		96,326	[3]	98,101	[4]
Held To Maturity Securities Fair Value		73,628	[3]	75,576	[4]
Other investment securities
FDIC loss-share asset		58,793		69,334
Mortgage servicing rights		193,698		196,889		$ 205,051	$ 211,405
Derivatives		13,097		14,094
Deposits
Time deposits		7,712,967		7,709,542
Total deposits		32,212,579		30,496,224
Notes payable:
Others		17,812		18,071
Notes Payable		1,557,972		1,574,852
Carrying amount
Financial Assets:
Cash And Due From Banks		340,225		362,394
Money market investments		3,653,347		2,890,217
Trading account securities, excluding derivatives	[5]	50,985		59,796
Available For Sale Securities	[5]	9,197,527		8,209,806
Investment securities held-to-maturity, at amortized cost		96,326		98,101
Other investment securities
FHLB Stock		57,262		58,033
FRB stock		93,911		94,672
Trust preferred securities fair value		13,198		13,198
Other investments		1,915		1,915
Total other investment securities		166,286		167,818
Loans held-for-sale		85,309		88,821
Loans covered under loss sharing agreements with the FDIC		524,209		542,528
FDIC loss-share asset		58,793		69,334
Mortgage servicing rights		193,698		196,889
Derivatives		13,097		14,094
Deposits
Demand deposits		24,499,612		22,786,682
Time deposits		7,712,967		7,709,542
Total deposits		32,212,579		30,496,224
Federal funds purchased and assets sold under agreements to repurchase		434,714		479,425
Other short-term borrowings	[6]	1,200		1,200
Notes payable:
Advances with the FHLB		655,521		672,670
Senior Long Term Notes		445,309		444,788
Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust		439,330		439,323
Others		17,812		18,071
Notes Payable		1,557,972		1,574,852
Derivatives		11,196		12,842
Contingent consideration		160,543		153,158
Fair Value
Financial Assets:
Cash And Cash Equivalents Fair Value Disclosure		340,225		362,394
Money Market Investments Fair Value		3,653,347		2,890,217
Trading account securities, excluding derivatives		50,985		59,796
Available For Sale Securities		9,197,527		8,209,806
Held To Maturity Securities Fair Value		73,628		75,576
Other investment securities
FHLB Stock		57,262		58,033
FRB stock		93,911		94,672
Trust preferred securities		13,198		13,198
Other investments		5,246		4,987
Total other investment securities		169,617		170,890
Loans held-for-sale		87,519		90,013
F D I C Indemnification Asset Fair Value Portion		54,171		63,187
Mortgage servicing rights		193,698		196,889
Derivatives		13,097		14,094
Deposits
Demand deposits		24,499,612		22,786,682
Time deposits		7,712,363		7,708,724
Deposits		32,211,975		30,495,406
Federal funds purchased and assets sold under agreements to repurchase		434,715		479,439
Other short-term borrowings		1,200		1,200
Notes payable:
FHLB advances		654,939		671,872
Unsecured senior debt securities		471,753		466,263
Junior subordinated deferrable interest debentures		402,973		399,370
Others		17,812		18,071
Notes payable		1,547,477		1,555,576
Derivatives		11,196		12,842
Contingent consideration		160,543		153,158
Obligations of Puerto Rico, States and political subdivisions
Financial Assets:
Available For Sale Securities		20,909		22,771
Investment securities held-to-maturity, at amortized cost		94,253		96,027
Held To Maturity Securities Fair Value		71,589		73,540
Obligations of Puerto Rico, States and political subdivisions | Carrying amount
Financial Assets:
Investment securities held-to-maturity, at amortized cost		94,253		96,027
Obligations of Puerto Rico, States and political subdivisions | Fair Value
Financial Assets:
Held To Maturity Securities Fair Value		71,589		73,540
Collateralized Mortgage Obligations - Federal agencies
Financial Assets:
Available For Sale Securities		1,146,886		1,221,526
Investment securities held-to-maturity, at amortized cost		73		74
Held To Maturity Securities Fair Value		77		78
Collateralized Mortgage Obligations - Federal agencies | Carrying amount
Financial Assets:
Investment securities held-to-maturity, at amortized cost		73		74
Collateralized Mortgage Obligations - Federal agencies | Fair Value
Financial Assets:
Held To Maturity Securities Fair Value		77		78
Other
Financial Assets:
Available For Sale Securities		9,415		9,585
Investment securities held-to-maturity, at amortized cost		2,000		2,000
Held To Maturity Securities Fair Value		1,962		1,958
Other | Carrying amount
Financial Assets:
Investment securities held-to-maturity, at amortized cost		2,000		2,000
Other | Fair Value
Financial Assets:
Held To Maturity Securities Fair Value		1,962		1,958
Level 1
Financial Assets:
Cash And Cash Equivalents Fair Value Disclosure		340,225		362,394
Money Market Investments Fair Value		3,644,623		2,854,777
Trading account securities, excluding derivatives	[5]	0		0
Available For Sale Securities	[5]	0		0
Held To Maturity Securities Fair Value		0		0
Other investment securities
FHLB Stock		0		0
FRB stock		0		0
Trust preferred securities		0		0
Other investments		0		0
Total other investment securities		0		0
Loans held-for-sale		0		0
F D I C Indemnification Asset Fair Value Portion		0		0
Mortgage servicing rights		0		0
Derivatives		0		0
Deposits
Demand deposits		0		0
Time deposits		0		0
Deposits		0		0
Federal funds purchased and assets sold under agreements to repurchase		0		0
Other short-term borrowings	[6]	0		0
Notes payable:
FHLB advances		0		0
Unsecured senior debt securities		0		0
Junior subordinated deferrable interest debentures		0		0
Others		0		0
Notes payable		0		0
Derivatives		0		0
Contingent consideration		0		0
Level 1 | Obligations of Puerto Rico, States and political subdivisions
Financial Assets:
Held To Maturity Securities Fair Value		0		0
Level 1 | Collateralized Mortgage Obligations - Federal agencies
Financial Assets:
Held To Maturity Securities Fair Value		0		0
Level 1 | Other
Financial Assets:
Held To Maturity Securities Fair Value		0		0
Level 2
Financial Assets:
Cash And Cash Equivalents Fair Value Disclosure		0		0
Money Market Investments Fair Value		8,724		35,440
Trading account securities, excluding derivatives	[5]	44,996		53,118
Available For Sale Securities	[5]	9,196,238		8,208,414
Held To Maturity Securities Fair Value		1,736		1,738
Other investment securities
FHLB Stock		57,262		58,033
FRB stock		93,911		94,672
Trust preferred securities		13,198		13,198
Other investments		0		0
Total other investment securities		164,371		165,903
Loans held-for-sale		289		504
F D I C Indemnification Asset Fair Value Portion		0		0
Mortgage servicing rights		0		0
Derivatives		13,097		14,094
Deposits
Demand deposits		24,499,612		22,786,682
Time deposits		7,712,363		7,708,724
Deposits		32,211,975		30,495,406
Federal funds purchased and assets sold under agreements to repurchase		434,715		479,439
Other short-term borrowings	[6]	1,200		1,200
Notes payable:
FHLB advances		654,939		671,872
Unsecured senior debt securities		471,753		466,263
Junior subordinated deferrable interest debentures		402,973		399,370
Others		0		0
Notes payable		1,529,665		1,537,505
Derivatives		11,196		12,842
Contingent consideration		0		0
Level 2 | Obligations of Puerto Rico, States and political subdivisions
Financial Assets:
Held To Maturity Securities Fair Value		0		0
Level 2 | Collateralized Mortgage Obligations - Federal agencies
Financial Assets:
Held To Maturity Securities Fair Value		0		0
Level 2 | Other
Financial Assets:
Held To Maturity Securities Fair Value		1,736		1,738
Level 3
Financial Assets:
Cash And Cash Equivalents Fair Value Disclosure		0		0
Money Market Investments Fair Value		0		0
Trading account securities, excluding derivatives	[5]	5,989		6,678
Available For Sale Securities	[5]	1,289		1,392
Held To Maturity Securities Fair Value		71,892		73,838
Other investment securities
FHLB Stock		0		0
FRB stock		0		0
Trust preferred securities		0		0
Other investments		5,246		4,987
Total other investment securities		5,246		4,987
Loans held-for-sale		87,230		89,509
F D I C Indemnification Asset Fair Value Portion		54,171		63,187
Mortgage servicing rights		193,698		196,889
Derivatives		0		0
Deposits
Demand deposits		0		0
Time deposits		0		0
Deposits		0		0
Federal funds purchased and assets sold under agreements to repurchase		0		0
Other short-term borrowings	[6]	0		0
Notes payable:
FHLB advances		0		0
Unsecured senior debt securities		0		0
Junior subordinated deferrable interest debentures		0		0
Others		17,812		18,071
Notes payable		17,812		18,071
Derivatives		0		0
Contingent consideration		160,543		153,158
Level 3 | Obligations of Puerto Rico, States and political subdivisions
Financial Assets:
Held To Maturity Securities Fair Value		71,589		73,540
Level 3 | Collateralized Mortgage Obligations - Federal agencies
Financial Assets:
Held To Maturity Securities Fair Value		77		78
Level 3 | Other
Financial Assets:
Held To Maturity Securities Fair Value		226		220
Non-covered loans | Carrying amount
Other investment securities
Loans held in portfolio, net		22,217,996		22,263,446
Non-covered loans | Fair Value
Other investment securities
Loans Receivable, Fair Value Disclosure		20,479,513		20,578,904
Non-covered loans | Level 1
Other investment securities
Loans Receivable, Fair Value Disclosure		0		0
Non-covered loans | Level 2
Other investment securities
Loans Receivable, Fair Value Disclosure		0		0
Non-covered loans | Level 3
Other investment securities
Loans Receivable, Fair Value Disclosure		20,479,513		20,578,904
Covered loans | Fair Value
Other investment securities
Loans Receivable, Fair Value Disclosure		491,393		515,808
Covered loans | Level 1
Other investment securities
Loans Receivable, Fair Value Disclosure		0		0
Covered loans | Level 2
Other investment securities
Loans Receivable, Fair Value Disclosure		0		0
Covered loans | Level 3
Other investment securities
Loans Receivable, Fair Value Disclosure		$ 491,393		$ 515,808

[1] Includes $4.9 billion pledged to secure public and trust deposits, assets sold under agreements to repurchase, credit facilities and loan servicing agreements that the secured parties are not permitted to sell or repledge the collateral, of which $4.2 billion serve as collateral for public funds.

[2] Includes $4.1 billion pledged to secure public and trust deposits, assets sold under agreements to repurchase, credit facilities and loan servicing agreements that the secured parties are not permitted to sell or repledge the collateral, of which $3.4 billion serve as collateral for public funds.

[3] Includes $94.3 million pledged to secure public and trust deposits that the secured parties are not permitted to sell or repledge the collateral.

[4] Includes $53.1 million pledged to secure public and trust deposits that the secured parties are not permitted to sell or repledge the collateral.

[5] Refer to Note 24 to the C onsolidated F inancial S tatements for the fair value by class of financial asset and its hierarchy level.

[6] Refer to Note 16 to the Consolidated F inancial S tatements for the composition of other short-term borrowings.