Loans and Allowance for Loan Losses - Purchased Credit-Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
PCI Loans, Carrying Value [Abstract]
Unpaid principal balance	$ 3,400		$ 4,977
Carrying value	2,849		3,681
Accretable Yield [Roll Forward]
Balance at beginning of period	2,618	$ 4,027
Removals	(778)	(77)
Accretion	(98)	(119)
Reclassifications from nonaccretable difference	0	0
Balance at end of period	1,742	$ 3,831
Commercial loans \| Commercial and industrial
PCI Loans, Carrying Value [Abstract]
Unpaid principal balance	53		237
Carrying value	38		175
Commercial real estate loans
PCI Loans, Carrying Value [Abstract]
Unpaid principal balance	3,124		4,329
Carrying value	2,741		3,437
Commercial real estate loans \| Construction
PCI Loans, Carrying Value [Abstract]
Unpaid principal balance	0		187
Carrying value	0		1
Residential loans \| Home equity
PCI Loans, Carrying Value [Abstract]
Unpaid principal balance	223		224
Carrying value	$ 70		$ 68

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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=6379141&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=27045933&loc=d3e13503-111538

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- Definition

Amount of decrease from accretion 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 15
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=27045933&loc=d3e13503-111538

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-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

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Amount of reduction, resulting from a sale or transfer of a loan, in 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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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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No definition available.

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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.

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- Definition

The recorded balance, net of any applicable reductions (for example, unamortized accretable yield and allowance for loan losses). This relates to loans not accounted for debt securities with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ 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)(1)
-URI http://asc.fasb.org/extlink&oid=6379141&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=27045933&loc=d3e13503-111538

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- Definition

The undiscounted sum of all amounts, including amounts deemed principal, interest, fees, penalties, and other under the loan, owed to the investor at the reporting date, whether or not currently due and whether or not any such amounts have been written or charged off by the investor. This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ 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=27045933&loc=d3e13503-111538

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