Fair value and gross unrealized losses of investment securities held-to-maturity, aggregated by investment category and length of time individual securities have been in a continuous unrealized loss position (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	$ 619	$ 373
Less than 12 months Gross Unrealized Losses	6	2
12 months or more Fair Value	42,089	45,969
12 months or more Gross Unrealized Losses	16,196	12,316
Total Fair Value	42,708	46,342
Total Gross Unrealized Losses	16,202	12,318
Puerto Rico States And Political Subdivisions Debt Securities [Member]
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	619	373
Less than 12 months Gross Unrealized Losses	6	2
12 months or more Fair Value	42,089	45,969
12 months or more Gross Unrealized Losses	16,196	12,316
Total Fair Value	42,708	46,342
Total Gross Unrealized Losses	16,202	12,318
Collateralized Mortgage Obligations Issued By U S Government Sponsored Enterprises And U S Government [Member]
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	0
Less than 12 months Gross Unrealized Losses	0
12 months or more Fair Value	0
12 months or more Gross Unrealized Losses	0
Total Fair Value	0
Total Gross Unrealized Losses	0
Collateralized Mortgage Obligations Issued By Private Enterprise [Member]
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	0	0
Less than 12 months Gross Unrealized Losses	0	0
12 months or more Fair Value	0	0
12 months or more Gross Unrealized Losses	0	0
Total Fair Value	0	0
Total Gross Unrealized Losses	0	0
US Treasury Securities [Member]
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	0	0
Less than 12 months Gross Unrealized Losses	0	0
12 months or more Fair Value	0	0
12 months or more Gross Unrealized Losses	0	0
Total Fair Value	0	0
Total Gross Unrealized Losses	0	0
Other Securities [Member]
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	0	0
Less than 12 months Gross Unrealized Losses	0	0
12 months or more Fair Value	0	0
12 months or more Gross Unrealized Losses	0	0
Total Fair Value	0	0
Total Gross Unrealized Losses	$ 0	$ 0