Accumulated Other Comprehensive Income (Loss) - Schedule of Changes in Accumulated Other Comprehensive Income (Loss) by Component Net of Tax (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized holding gain (loss) on available-for-sale securities arising during the period, Pretax	$ 519	$ (1,386)	$ 1,327	$ (618)
Reclassify gain included in income, Pretax		(21)		(56)
Unrealized holding gain (loss) on available-for-sale securities arising during the period, Tax Effect	268	(416)	559	(137)
Reclassify gain included in income, Tax Effect		7		19
Beginning balance, After-tax			(417)
Other comprehensive income (loss)	521	(822)	1,085	(302)
Ending Balance, After-tax	668		668
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance, Pretax	223	360	(631)	(427)
Unrealized holding gain (loss) on available-for-sale securities arising during the period, Pretax	519	(1,386)	1,327	(618)
Reclassify gain included in income, Pretax		(21)		(56)
Amortization of held-to-maturity discount resulting from transfer , Pretax	270	162	317	216
Total other comprehensive income (loss), Pretax	789	(1,245)	1,644	(458)
Ending balance, Pretax	1,013	(885)	1,013	(885)
Beginning balance, Tax Effect	(76)	(122)	214	145
Unrealized holding gain (loss) on available-for-sale securities arising during the period, Tax Effect	(176)	471	(451)	210
Reclassify gain included in income, Tax Effect		7		19
Amortization of held-to-maturity discount resulting from transfer, Tax Effect	(92)	(55)	(108)	(73)
Total other comprehensive income (loss), Tax Effect	(268)	423	(559)	156
Ending Balance, Tax Effect	(345)	301	(345)	301
Beginning balance, After-tax	147	238	(417)	(282)
Unrealized holding gain (loss) on available-for-sale securities arising during the period, After-tax	343	(915)	876	(408)
Reclassify gain included in income, After-tax		(14)		(37)
Amortization of held-to-maturity discount resulting from transfer, After-tax	178	107	209	143
Other comprehensive income (loss)	521	(822)	1,085	(302)
Ending Balance, After-tax	$ 668	$ (584)	$ 668	$ (584)