Note Loans (Carrying amount of Westernbank loans accounted for pursuant to ASC310-30) (Detail) - Westernbank Puerto Rico - Acquired loans in an FDIC assisted transaction - ASC Subtopic 310-30 - USD ($) $ in Thousands	Mar. 31, 2017		Dec. 31, 2016		Mar. 31, 2016		Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount	$ 1,688,900	[1],[2]	$ 1,738,329	[2]	$ 1,935,441	[1]	$ 1,974,501
Less: Allowance for loan losses	(66,544)		(68,877)		(62,967)
Carrying amount, net of allowance	1,622,356		1,669,452		1,872,474
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount	971,391		999,621
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount	100,759		103,476
Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount	1,668		1,668
Mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount	595,584		613,730
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount	19,498		19,834
Non-credit Impaired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount	1,648,328	[1],[2]	1,695,381	[2]	1,865,940	[1]	1,898,146
Less: Allowance for loan losses	(59,283)		(61,855)		(58,703)
Carrying amount, net of allowance	1,589,045		1,633,526		1,807,237
Non-credit Impaired Loans | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount	957,360		985,181
Non-credit Impaired Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount	100,759		103,476
Non-credit Impaired Loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount	0		0
Non-credit Impaired Loans | Mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount	571,594		587,949
Non-credit Impaired Loans | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount	18,615		18,775
Credit Impaired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount	40,572	[1],[2]	42,948	[2]	69,501	[1]	$ 76,355
Less: Allowance for loan losses	(7,261)		(7,022)		(4,264)
Carrying amount, net of allowance	33,311		35,926		$ 65,237
Credit Impaired Loans | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount	14,031		14,440
Credit Impaired Loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount	0		0
Credit Impaired Loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount	1,668		1,668
Credit Impaired Loans | Mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount	23,990		25,781
Credit Impaired Loans | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount	$ 883		$ 1,059

[1] The carrying amount of loans acquired from Westernbank and accounted for under ASC 310-30 which remain subject to the loss sharing agreement with the FDIC amounted to approximately $ 542 million as of March 31, 2017 (March 31, 2016- $615 million).

[2] The carrying amount of loans acquired from Westernbank and accounted for under ASC 310-30 which remains subject to the loss sharing agreement with the FDIC amounted to approximately $542 million as of March 31, 2017 and $563 million as of December 31, 2016.