Line items represent reporting concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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-Article 12
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Investment in community development loans.

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Securities pledged to secure public deposit carrying value.

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Amount of equity securities categorized neither as held-to-maturity nor as trading.

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Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

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The amount of unfunded commitments for which the entity is obligated, to those certain investments for which net asset value per share is calculated (including by unit, membership interest, or other equity (ownership interest) unit measure) (alternative investments).

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The amount by which the fair value of an investment is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income.

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For an unclassified balance sheet, this item represents investments in common and preferred stocks and other forms of securities that provide ownership interests in a corporation.

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-Publisher FASB
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Investment Securities - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Investment [Line Items]
Equity securities, at fair value	$ 18,397,000		$ 18,089,000
Cumulative adjustment for adoption of ASU 2016-01			0
Market value loss	18,000
Other than temporary impairments	0	$ 0
Securities, carrying value	388,600,000		$ 400,400,000
Investment in government guaranteed loans, mortgage-backed securities, small business loans	9,500,000
Investment in community development loans	$ 3,500,000
Redemption of funds	60 days
Unfunded commitments	$ 0
Other financial institutions
Investment [Line Items]
Market value of equities	5,300,000
Community reinvestment funds
Investment [Line Items]
Equity securities included in investment funds	$ 13,100,000