Securities - Summary of Investments in an Unrealized Loss Position that were Temporarily Impaired (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Less than 12 months - Fair Value	$ 13,509	$ 52,580
Securities available for sale, 12 months or more - Fair Value	12,296	14,462
Securities available for sale, Total - Fair Value	25,805	67,042
Securities available for sale, Less than 12 months - Unrealized (Loss)	(37)	(479)
Securities available for sale, 12 months or more - Unrealized (Loss)	(184)	(414)
Total Unrealized (Loss)	(221)	(893)
Securities held to maturity, Less than 12 months - Fair Value	10,783	35,843
Securities held to maturity, 12 months or more - Fair Value	0	0
Securities held to maturity, Total - Fair Value	10,783	35,843
Securities held to maturity, Less than 12 months - Unrealized (Loss)	(57)	(345)
Securities held to maturity, 12 months or more - Unrealized (Loss)	0	0
Total Unrealized (Loss)	(57)	(345)
Total securities, Less than 12 months - Fair Value	24,292	88,423
Total securities, 12 months or more - Fair Value	12,296	14,462
Total securities, Total - Fair Value	36,588	102,885
Total securities, Less than 12 months - Unrealized (Loss)	(94)	(824)
Total securities, 12 months or more - Unrealized (Loss)	(184)	(414)
Total Unrealized (Loss)	(278)	(1,238)
U.S. Agency and Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Less than 12 months - Fair Value	12,958	50,185
Securities available for sale, 12 months or more - Fair Value	11,779	13,409
Securities available for sale, Total - Fair Value	24,737	63,594
Securities available for sale, Less than 12 months - Unrealized (Loss)	(36)	(464)
Securities available for sale, 12 months or more - Unrealized (Loss)	(169)	(379)
Total Unrealized (Loss)	(205)	(843)
Securities held to maturity, Less than 12 months - Fair Value	8,935	32,791
Securities held to maturity, 12 months or more - Fair Value	0	0
Securities held to maturity, Total - Fair Value	8,935	32,791
Securities held to maturity, Less than 12 months - Unrealized (Loss)	(53)	(326)
Securities held to maturity, 12 months or more - Unrealized (Loss)	0	0
Total Unrealized (Loss)	(53)	(326)
Obligations of States and Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Less than 12 months - Fair Value	551	2,395
Securities available for sale, 12 months or more - Fair Value	517	1,053
Securities available for sale, Total - Fair Value	1,068	3,448
Securities available for sale, Less than 12 months - Unrealized (Loss)	(1)	(15)
Securities available for sale, 12 months or more - Unrealized (Loss)	(15)	(35)
Total Unrealized (Loss)	(16)	(50)
Securities held to maturity, Less than 12 months - Fair Value	1,848	3,052
Securities held to maturity, 12 months or more - Fair Value	0	0
Securities held to maturity, Total - Fair Value	1,848	3,052
Securities held to maturity, Less than 12 months - Unrealized (Loss)	(4)	(19)
Securities held to maturity, 12 months or more - Unrealized (Loss)	0	0
Total Unrealized (Loss)	$ (4)	$ (19)

Available for sale securities and held to maturity securities continuous unrealized loss position accumulated loss.

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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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.

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