Securities - Contractual Maturity of All Debt Securities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Available for Sale
Within 1 year, Amortized Cost	$ 24,731
After 1 year but within 5 years, Amortized Cost	151,886
After 5 year but within 10 years, Amortized Cost	6,470
After 10 years, Amortized Cost	8,753
Mortgage-backed securities-residential, Amortized Cost	349,216
Total, Amortized Cost	541,056
Within 1 year, Fair Value	24,830
After 1 year but within 5 years, Fair Value	152,384
After 5 year but within 10 years, Fair Value	6,558
After 10 years, Fair Value	8,753
Mortgage-backed securities-residential, Fair Value	339,695
Total, Fair Value	532,220
Held to Maturity
Within 1 year, Amortized Cost
After 1 year but within 5 years, Amortized Cost	3,105
After 5 year but within 10 years, Amortized Cost
After 10 years, Amortized Cost
Mortgage-backed securities-residential, Amortized Cost	3,133
Total, Amortized Cost	6,238	10,225
Within 1 year, Fair Value
After 1 year but within 5 years, Fair Value	3,174
After 5 year but within 10 years, Fair Value
After 10 years, Fair Value
Mortgage-backed securities-residential, Fair Value	3,382
Held To Maturity Securities, Estimated Fair Value	$ 6,556	$ 10,825