Securities - Additional Information (Detail) - USD ($) |
3 Months Ended | |||
|---|---|---|---|---|
Mar. 31, 2018 |
Mar. 31, 2017 |
Jan. 01, 2018 |
Dec. 31, 2017 |
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| Investment Securities [Line Items] | ||||
| Securities available for sale | $ 570,351,000 | $ 578,804,000 | ||
| Retained earnings | (77,691,000) | (70,575,000) | ||
| Net deferred tax asset | 35,600,000 | 38,300,000 | ||
| Impairment charges on securities in continuous unrealized loss position for 12 months or longer | 0 | 0 | ||
| Net realized gains (losses) on sales of securities | 957,000 | $ (269,000) | ||
| Net gain (loss) in earnings resulting from sale of securities | (428,000) | 269,000 | ||
| Net unrealized gains (losses) recorded in comprehensive income | (529,000) | $ 319,000 | ||
| Securities Pledged as Collateral [Member] | ||||
| Investment Securities [Line Items] | ||||
| Securities available for sale | $ 130,800,000 | $ 130,100,000 | ||
| ASU 2016-01 [Member] | ||||
| Investment Securities [Line Items] | ||||
| Securities available for sale | $ (529,000) | |||
| Retained earnings | 382,000 | |||
| Net deferred tax asset | $ 147,000 | |||
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- Definition Amount of accumulated pre-tax unrealized loss on investments in available-for-sale securities that have been in a loss position for twelve months or longer. No definition available.
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- Definition Investment Securities [Line Items] No definition available.
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- Definition Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The difference between the carrying value and the sale price of equity securities, not separately or otherwise categorized as trading or available-for-sale. This element includes investments in which the entity holds a small ownership stake (generally, less than 20% of the shares outstanding) and cannot exert significant influence. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount after tax, before reclassification adjustments, of unrealized holding gain (loss) on available-for-sale securities and unrealized holding gain (loss) related to transfers of securities into the available-for-sale classification and out of the held-to-maturity classification. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The cumulative amount of the reporting entity's undistributed earnings or deficit. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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