Fair Value Measurements - Summary of Company's Securities Available-for-Sale (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Schedule Of Available For Sale Securities [Line Items]
Amortized cost	$ 67,501	$ 64,839
Gross unrealized gains	70	55
Gross unrealized losses	(54)	(31)
Securities available-for-sale	67,517	64,863
Municipal Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost	6,051	11,693
Gross unrealized gains	1	5
Gross unrealized losses	(1)	(2)
Securities available-for-sale	6,051	11,696
Corporate Bonds [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized cost	61,450	53,146
Gross unrealized gains	69	50
Gross unrealized losses	(53)	(29)
Securities available-for-sale	$ 61,466	$ 53,167

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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

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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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