Note Allowance for loan losses (T D R that subsequently defaulted) (Detail) $ in Thousands		3 Months Ended
		Mar. 31, 2016 USD ($) loans	Mar. 31, 2015 USD ($) loans
Troubled Debt Restructuring
Loan count | loans		186	208
Recorded investment as of first default date | $		$ 8,300	$ 5,336
Commercial multi-family
Troubled Debt Restructuring
Loan count | loans		0	0
Recorded investment as of first default date | $		$ 0	$ 0
CRE non-owner occupied
Troubled Debt Restructuring
Loan count | loans		2	0
Recorded investment as of first default date | $		$ 327	$ 0
CRE owner occupied
Troubled Debt Restructuring
Loan count | loans		6	1
Recorded investment as of first default date | $		$ 2,456	$ 291
Commercial and industrial
Troubled Debt Restructuring
Loan count | loans		0	1
Recorded investment as of first default date | $		$ 0	$ 90
Construction
Troubled Debt Restructuring
Loan count | loans		0	2
Recorded investment as of first default date | $		$ 0	$ 1,192
Mortgages
Troubled Debt Restructuring
Loan count | loans		27	22
Recorded investment as of first default date | $		$ 3,235	$ 1,695
Legacy
Troubled Debt Restructuring
Loan count | loans		0	0
Recorded investment as of first default date | $		$ 0	$ 0
Leasing
Troubled Debt Restructuring
Loan count | loans		0	0
Recorded investment as of first default date | $		$ 0	$ 0
Credit cards
Troubled Debt Restructuring
Loan count | loans		106	153
Recorded investment as of first default date | $		$ 1,122	$ 1,792
Home equity lines of credit
Troubled Debt Restructuring
Loan count | loans		0	0
Recorded investment as of first default date | $		$ 0	$ 0
Personal
Troubled Debt Restructuring
Loan count | loans		43	22
Recorded investment as of first default date | $		$ 1,139	$ 178
Auto
Troubled Debt Restructuring
Loan count | loans		1	5
Recorded investment as of first default date | $		$ 17	$ 96
Other
Troubled Debt Restructuring
Loan count | loans		1	2
Recorded investment as of first default date | $		$ 4	$ 2
PUERTO RICO
Troubled Debt Restructuring
Loan count | loans	[1]	186	208
Recorded investment as of first default date | $	[1]	$ 8,300	$ 5,336
PUERTO RICO | Commercial multi-family
Troubled Debt Restructuring
Loan count | loans		0	0
Recorded investment as of first default date | $		$ 0	$ 0
PUERTO RICO | CRE non-owner occupied
Troubled Debt Restructuring
Loan count | loans		2	0
Recorded investment as of first default date | $		$ 327	$ 0
PUERTO RICO | CRE owner occupied
Troubled Debt Restructuring
Loan count | loans		6	1
Recorded investment as of first default date | $		$ 2,456	$ 291
PUERTO RICO | Commercial and industrial
Troubled Debt Restructuring
Loan count | loans		0	1
Recorded investment as of first default date | $		$ 0	$ 90
PUERTO RICO | Construction
Troubled Debt Restructuring
Loan count | loans		0	2
Recorded investment as of first default date | $		$ 0	$ 1,192
PUERTO RICO | Mortgages
Troubled Debt Restructuring
Loan count | loans		27	22
Recorded investment as of first default date | $		$ 3,235	$ 1,695
PUERTO RICO | Leasing
Troubled Debt Restructuring
Loan count | loans		0	0
Recorded investment as of first default date | $		$ 0	$ 0
PUERTO RICO | Credit cards
Troubled Debt Restructuring
Loan count | loans		106	153
Recorded investment as of first default date | $		$ 1,122	$ 1,792
PUERTO RICO | Home equity lines of credit
Troubled Debt Restructuring
Loan count | loans		0	0
Recorded investment as of first default date | $		$ 0	$ 0
PUERTO RICO | Personal
Troubled Debt Restructuring
Loan count | loans		43	22
Recorded investment as of first default date | $		$ 1,139	$ 178
PUERTO RICO | Auto
Troubled Debt Restructuring
Loan count | loans		1	5
Recorded investment as of first default date | $		$ 17	$ 96
PUERTO RICO | Other
Troubled Debt Restructuring
Loan count | loans		1	2
Recorded investment as of first default date | $		$ 4	$ 2
UNITED STATES
Troubled Debt Restructuring
Loan count | loans		0	0
Recorded investment as of first default date | $		$ 0	$ 0
UNITED STATES | Commercial multi-family
Troubled Debt Restructuring
Loan count | loans		0	0
Recorded investment as of first default date | $		$ 0	$ 0
UNITED STATES | CRE non-owner occupied
Troubled Debt Restructuring
Loan count | loans		0	0
Recorded investment as of first default date | $		$ 0	$ 0
UNITED STATES | CRE owner occupied
Troubled Debt Restructuring
Loan count | loans		0	0
Recorded investment as of first default date | $		$ 0	$ 0
UNITED STATES | Commercial and industrial
Troubled Debt Restructuring
Loan count | loans		0	0
Recorded investment as of first default date | $		$ 0	$ 0
UNITED STATES | Construction
Troubled Debt Restructuring
Loan count | loans		0	0
Recorded investment as of first default date | $		$ 0	$ 0
UNITED STATES | Mortgages
Troubled Debt Restructuring
Loan count | loans		0	0
Recorded investment as of first default date | $		$ 0	$ 0
UNITED STATES | Legacy
Troubled Debt Restructuring
Loan count | loans		0	0
Recorded investment as of first default date | $		$ 0	$ 0
UNITED STATES | Credit cards
Troubled Debt Restructuring
Loan count | loans		0	0
Recorded investment as of first default date | $		$ 0	$ 0
UNITED STATES | Home equity lines of credit
Troubled Debt Restructuring
Loan count | loans		0	0
Recorded investment as of first default date | $		$ 0	$ 0
UNITED STATES | Personal
Troubled Debt Restructuring
Loan count | loans		0	0
Recorded investment as of first default date | $		$ 0	$ 0
UNITED STATES | Auto
Troubled Debt Restructuring
Loan count | loans		0	0
Recorded investment as of first default date | $		$ 0	$ 0
UNITED STATES | Other
Troubled Debt Restructuring
Loan count | loans		0	0
Recorded investment as of first default date | $		$ 0	$ 0

[1] Excludes loans for which the Corporation has entered into liquidation agreements with borrowers and guarantors and is accepting payments which differ from the contractual payment schedule. The Corporation considers these as defaulted loans and does not intent to return them to accrual status.