Investments held-to-maturity-Additional Information (Detail) - Entity [Domain] - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 101,861	$ 103,170
Puerto Rico States And Political Subdivisions Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	100,270	$ 101,573
Puerto Rico States And Political Subdivisions Debt Securities [Member] | Munis Payable From Real and Personal Property Taxes [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	59,000
Puerto Rico States And Political Subdivisions Debt Securities [Member] | Munis Not Guaranteed By Puerto Rico Central Government [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 42,000