Securities - Additional Information (Details) - USD ($)	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2018
Schedule Of Investments [Line Items]
Reclassification from accumulated other comprehensive income, current period, net of tax	$ 239,000	$ 662,000
ASU 2016-01 [Member] \| Retained Earnings [Member]
Schedule Of Investments [Line Items]
Reclassification from accumulated other comprehensive income, current period, net of tax		$ 10,000

Amount after tax of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of available-for-sale securities.

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