Loans and Allowance for Loan Losses (Changes in Carrying Amount of Purchased Credit Impaired Loans and Related Accretable Yield) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2018	Dec. 31, 2017
Loans and Allowance for Loan Losses [Abstract]
Carrying Amount of Loans, Balance at beginning of period	$ 153,403	$ 190,915
Carrying Amount of Loans, Addition of cost recovery loans - FNBC I		15,000
Carrying Amount of Loans, Payments received, net	(30,448)	(69,591)
Carrying Amount of Loans, Accretion	12,080	17,079
Carrying Amount of Loans, Balance at end of period	135,035	153,403
Accretable Yield, Balance at beginning of period	62,517	113,686
Accretable Yield, Payments received, net	(4,564)	(7,412)
Accretable Yield, Accretion	(12,080)	(17,079)
Accretable Yield, Increase (decrease) in expected cash flows based on actual cash flow and changes in cash flow assumptions	(2,801)	(30,379)
Accretable Yield, Net transfers from nonaccretable difference to accretable yield		3,701
Accretable Yield, Balance at end of period	$ 43,072	$ 62,517

Certain loans acquired in transfer not accounted for as debt securities accretable yield payment received net.

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- Definition

Certain Loans Acquired In Transfer Not Accounted For As Debt Securities, Additions

+ References

No definition available.

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- Definition

Certain loans acquired in transfer not accounted for as debt securities, carrying amount, accretion.

+ References

No definition available.

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- Definition

Certain loans acquired in transfer not accounted for as debt securities, payments received, net.

+ References

No definition available.

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- Definition

Loans Accounted For Under ASC 310-30

+ References

No definition available.

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- Definition

Net Accretable Discount Decrease Increase In Expected Cash Flows Based On Actual Cash Flow And Changes In Cash Flow

+ References

No definition available.

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- Definition

Amount of the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities with evidence of deterioration of credit quality.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=82894903&loc=d3e15032-111544

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 15
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82894507&loc=d3e13503-111538

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- Definition

Amount of accretion recognized for the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities, with evidence of deterioration of credit quality.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 15
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82894507&loc=d3e13503-111538

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=82894903&loc=d3e15032-111544

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- Definition

Amount of reclassification (to) from nonaccretable difference (from) to the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities with evidence of deterioration of credit quality.

+ References

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