Investment Securities - Summary of Securities Available for Sale in an Unrealized Loss Position (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	$ 442,162	$ 33,892
Less than 12 months, Unrealized Losses	11,362	580
12 months or longer, Fair Value	35,402	59,026
12 months or longer, Unrealized Losses	32,641	58,137
U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	61,517	25,170
Less than 12 months, Unrealized Losses	748	52
12 months or longer, Fair Value	0	0
12 months or longer, Unrealized Losses	0	0
State and Political Subdivisions [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	2,353	126
Less than 12 months, Unrealized Losses	26	1
12 months or longer, Fair Value	0	0
12 months or longer, Unrealized Losses	0	0
Residential Mortgage-Backed Securities, Agency [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	160,835
Less than 12 months, Unrealized Losses	1,815
12 months or longer, Fair Value	0
12 months or longer, Unrealized Losses	0
Commercial Mortgage-Backed Securities Agency [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	208,979
Less than 12 months, Unrealized Losses	8,740
12 months or longer, Fair Value	0
12 months or longer, Unrealized Losses	0
Residential Mortgage-Backed Securities, Non-agency [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value		0
Less than 12 months, Unrealized Losses		0
12 months or longer, Fair Value		10,879
12 months or longer, Unrealized Losses		458
Asset-Backed Securities [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	7,976	7,993
Less than 12 months, Unrealized Losses	31	20
12 months or longer, Fair Value	0	0
12 months or longer, Unrealized Losses	0	0
Trust Preferred Collateralized Debt Obligations [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	0	0
Less than 12 months, Unrealized Losses	0	0
12 months or longer, Fair Value	27,167	40,613
12 months or longer, Unrealized Losses	30,623	54,186
Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	502	0
Less than 12 months, Unrealized Losses	2	0
12 months or longer, Fair Value	8,210	7,221
12 months or longer, Unrealized Losses	2,017	3,469
Marketable Equity Securities [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	0	603
Less than 12 months, Unrealized Losses	0	507
12 months or longer, Fair Value	25	313
12 months or longer, Unrealized Losses	$ 1	$ 24