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Deposits - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Banking and Thrift [Abstract]
Interest on time accounts	$ 576	$ 743	$ 853
Held-to-maturity securities pledged as collateral	107,800
CDARS balance in reciprocal deposit program	13,500	15,100
ICS balance in reciprocal deposit program	41,000	29,000
DDM balance in reciprocal deposit program	29,200	36,400
One-way CDARS deposits	4,200	361
Deposit overdrafts reclassified as loan balances	224	229
Related party deposit liabilities	$ 29,900	$ 7,300

X

- Definition

Deposits, Demand Deposit Marketplace (DDM)

+ References

No definition available.

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X

- Definition

Deposits, Money Market Deposits, Insured Cash Sweep (ICS)

+ References

No definition available.

+ Details

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X

- Definition

Certificate of Deposit Account Registry Service, a special type of certificate of deposit whereby the participating bank accepts deposits in excess of the FDIC insured maximum and places the deposits through a network to member banks in the CDARS(R) network in increments of less than the FDIC insured maximum to provide the depositor full FDIC insurance coverage.

+ References

No definition available.

+ Details

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X

- Definition

Time Deposits, Certificate Of Deposit Account Registry Service (CDARS), One-Way

+ References

No definition available.

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- References

No definition available.

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- Definition

Amount of deposits held by the entity that have been reclassified as loan balances receivable, for example, but not limited to, overdrafts receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 405
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=50488274&loc=d3e64164-112818

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X

- Definition

The carrying amount of held-to-maturity securities that serve as collateral for borrowings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5086-111524

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X

- Definition

The aggregate interest expense incurred on time deposits, including certificates of deposits, in domestic offices.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.6)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

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- Definition

Amount of deposits held by the entity for a related party (entity, shareholder, employee).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(k))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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