The number of securities in continuous unrealized loss position.

No definition available.

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- Definition

Number of securities in continuous unrealized loss position for more than 12 months.

+ References

No definition available.

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
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- Definition

Amount of restricted investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 50
-Paragraph 1A
-Subparagraph (b)(1)(i)
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- Definition

Indicates type of restriction on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Amount, before tax, of other-than-temporary impairment (OTTI) on investment in debt security measured at amortized cost (held-to-maturity), recognized in earnings and other comprehensive income (OCI).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

Line items represent financial 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.

+ References

No definition available.

+ Details

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Investment securities - Additional Information (Details) $ in Thousands	3 Months Ended		6 Months Ended		9 Months Ended	12 Months Ended
	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) security	Dec. 31, 2017 USD ($)
Available-for-sale and Held-to-maturity securities
Carrying value of securities pledged					us-gaap:AssetPledgedAsCollateralMember	us-gaap:AssetPledgedAsCollateralMember
Number of investment securities held					209
Other-than-temporary impairments recognized \| $					$ 0
Collateral Pledged
Available-for-sale and Held-to-maturity securities
Carrying value of securities pledged \| $					$ 164,516	$ 163,936
State and Municipals, Tax-exempt
Available-for-sale and Held-to-maturity securities
Number of investment securities held					118
Number of securities in continuous unrealized loss positions 12 months or longer					23
Credit Concentration Risk \| Total Stockholders' Equity \| US Government Agency and Sponsored Enterprises \| Minimum
Available-for-sale and Held-to-maturity securities
Maximum percentage of stockholders' equity exceeded for securities of any individual issuer			10.00%			10.00%
U.S. Government-sponsored enterprises state and municipals
Available-for-sale and Held-to-maturity securities
Number of investment securities held					38
Number of securities in continuous unrealized loss positions 12 months or longer					30
Other-than-temporary impairments recognized \| $	$ 0	$ 0	$ 0	$ 0
Mortgage-backed Securities, U.S. Government-sponsored enterprises
Available-for-sale and Held-to-maturity securities
Number of investment securities held					44
Number of securities in continuous unrealized loss positions 12 months or longer					28
U.S. Treasuries
Available-for-sale and Held-to-maturity securities
Number of investment securities held					9
Number of securities in continuous unrealized loss positions 12 months or longer					6