Available-For-Sale Securities in Continuous Unrealized Loss Position (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	$ 107,257	$ 4,040
Less than 12 Months, Unrealized Losses	(1,009)	(17)
12 Months or Longer, Fair Value	123,958	146,382
12 Months or Longer, Unrealized Losses	(10,542)	(12,240)
Fair Value	231,215	150,422
Unrealized Losses	(11,551)	(12,257)
Municipal securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	20,138	1,112
Less than 12 Months, Unrealized Losses	(660)	(8)
12 Months or Longer, Fair Value	10,120	25,007
12 Months or Longer, Unrealized Losses	(820)	(684)
Fair Value	30,258	26,119
Unrealized Losses	(1,480)	(692)
U.S. Agency securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	3,041
Less than 12 Months, Unrealized Losses	(14)
12 Months or Longer, Fair Value	25,102	29,448
12 Months or Longer, Unrealized Losses	(967)	(1,017)
Fair Value	28,143	29,448
Unrealized Losses	(981)	(1,017)
Single Issue Trust Preferred Securities
Schedule of Available-for-sale Securities [Line Items]
12 Months or Longer, Fair Value	48,344	46,137
12 Months or Longer, Unrealized Losses	(7,507)	(9,685)
Fair Value	48,344	46,137
Unrealized Losses	(7,507)	(9,685)
Corporate securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	55,581
Less than 12 Months, Unrealized Losses	(136)
Fair Value	55,581
Unrealized Losses	(136)
Mortgage-backed Agency securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months, Fair Value	28,497	2,778
Less than 12 Months, Unrealized Losses	(199)	(3)
12 Months or Longer, Fair Value	40,246	45,790
12 Months or Longer, Unrealized Losses	(1,239)	(854)
Fair Value	68,743	48,568
Unrealized Losses	(1,438)	(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)
12 Months or Longer, Fair Value	146
12 Months or Longer, Unrealized Losses	(9)
Fair Value	146	150
Unrealized Losses	$ (9)	$ (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

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (a)(2)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563

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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.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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