Securities - Schedule of Gross Unrealized Losses and Fair Value of Securities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Schedule of Available-for-Sale Securities [Line Items]
Less Than 12 Months Estimated Fair Value	$ 156,316	$ 44,540
12 Months or More Estimated Fair Value	32,008	8,682
Total Estimated Fair Value	188,324	53,222
Less Than 12 Months Unrealized Losses	(5,396)	(386)
12 Months or More Unrealized Losses	(2,098)	(581)
Total Unrealized Losses	(7,494)	(967)
U.S. Government Sponsored Agencies [Member]
Schedule of Available-for-Sale Securities [Line Items]
Less Than 12 Months Estimated Fair Value	13,926	4,994
Total Estimated Fair Value	13,926	4,994
Less Than 12 Months Unrealized Losses	(1,021)	(6)
Total Unrealized Losses	(1,021)	(6)
State, County and Municipal Securities [Member]
Schedule of Available-for-Sale Securities [Line Items]
Less Than 12 Months Estimated Fair Value	47,401	15,595
12 Months or More Estimated Fair Value	3,794	505
Total Estimated Fair Value	51,195	16,100
Less Than 12 Months Unrealized Losses	(1,882)	(199)
12 Months or More Unrealized Losses	(292)	(11)
Total Unrealized Losses	(2,174)	(210)
Corporate Debt Securities [Member]
Schedule of Available-for-Sale Securities [Line Items]
12 Months or More Estimated Fair Value	4,826	4,560
Total Estimated Fair Value	4,826	4,560
12 Months or More Unrealized Losses	(261)	(547)
Total Unrealized Losses	(261)	(547)
Collateralized Debt Obligations [Member]
Schedule of Available-for-Sale Securities [Line Items]
Less Than 12 Months Estimated Fair Value
12 Months or More Estimated Fair Value
Total Estimated Fair Value
Less Than 12 Months Unrealized Losses
12 Months or More Unrealized Losses
Total Unrealized Losses
Mortgage-Backed Securities [Member]
Schedule of Available-for-Sale Securities [Line Items]
Less Than 12 Months Estimated Fair Value	94,989	23,951
12 Months or More Estimated Fair Value	23,388	3,617
Total Estimated Fair Value	118,377	27,568
Less Than 12 Months Unrealized Losses	(2,493)	(181)
12 Months or More Unrealized Losses	(1,545)	(23)
Total Unrealized Losses	$ (4,038)	$ (204)