Available-For-Sale Securities in Continuous Unrealized Loss Position (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	$ 90,326	$ 4,040
Less than 12 Months, Unrealized Losses	(415)	(17)
12 Months or Longer, Fair Value	123,452	146,382
12 Months or Longer, Unrealized Losses	(8,128)	(12,240)
Fair Value	213,778	150,422
Unrealized Losses	(8,543)	(12,257)
Municipal securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	13,702	1,112
Less than 12 Months, Unrealized Losses	(172)	(8)
12 Months or Longer, Fair Value	10,222	25,007
12 Months or Longer, Unrealized Losses	(483)	(684)
Fair Value	23,924	26,119
Unrealized Losses	(655)	(692)
U.S. Agency securities
Schedule of Available-for-sale Securities [Line Items]
12 Months or Longer, Fair Value	24,670	29,448
12 Months or Longer, Unrealized Losses	(577)	(1,017)
Fair Value	24,670	29,448
Unrealized Losses	(577)	(1,017)
Single Issue Trust Preferred Securities
Schedule of Available-for-sale Securities [Line Items]
12 Months or Longer, Fair Value	49,434	46,137
12 Months or Longer, Unrealized Losses	(6,433)	(9,685)
Fair Value	49,434	46,137
Unrealized Losses	(6,433)	(9,685)
Corporate securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	62,257
Less than 12 Months, Unrealized Losses	(144)
Fair Value	62,257
Unrealized Losses	(144)
Mortgage-backed Agency securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	14,367	2,778
Less than 12 Months, Unrealized Losses	(99)	(3)
12 Months or Longer, Fair Value	39,126	45,790
12 Months or Longer, Unrealized Losses	(635)	(854)
Fair Value	53,493	48,568
Unrealized Losses	$ (734)	(857)
Equity Securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value		150
Less than 12 Months, Unrealized Losses		(6)
Fair Value		150
Unrealized Losses		$ (6)

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for twelve months or longer.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

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-Section 50

-Paragraph 6

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Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale in a continuous loss position.

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