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	Jun. 30, 2013	Dec. 31, 2012
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	$ 52,854	$ 2,365
Less than 12 months Gross Unrealized Losses	1,156	35
12 months or more Fair Value	18,832	19,118
12 months or more Gross Unrealized Losses	713	427
Total Fair Value	71,686	21,483
Total Gross Unrealized Losses	1,869	462
Puerto Rico States And Political Subdivisions Debt Securities [Member]
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	27,855	2,365
Less than 12 months Gross Unrealized Losses	1,155	35
12 months or more Fair Value	18,832	19,118
12 months or more Gross Unrealized Losses	713	427
Total Fair Value	46,687	21,483
Total Gross Unrealized Losses	1,868	462
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	24,999	0
Less than 12 months Gross Unrealized Losses	1	0
12 months or more Fair Value	0	0
12 months or more Gross Unrealized Losses	0	0
Total Fair Value	24,999	0
Total Gross Unrealized Losses	$ 1	$ 0