Allowance for Loan Losses - Investments in Loans Considered to be Impaired and Related Information on Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Financing Receivable, Impaired [Line Items]
With a related allowance recorded, Recorded Investment	$ 2,492		$ 2,492		$ 991
With a related allowance recorded, Unpaid Principal Balance	2,492		2,492		2,460
Impaired Financing Receivable, Related Allowance	389		389		798
Without a related allowance recorded, Recorded Investment	37,970		37,970		40,944
Without a related allowance, Unpaid Principal Balance	43,901		43,901		48,539
Without a related allowance recorded, Related Allowance	0		0		0
Impaired Financing Receivable, Recorded Investment	40,462		40,462		41,935
Impaired Financing Receivable, Unpaid Principal Balance, Total	46,393		46,393		50,999
With a related allowance recorded, Average Recorded Investment	863	$ 5,879	39,203	$ 47,849
With a related allowance recorded, Interest Income Recognized	7	38	528	673
Without a related allowance recorded, Average Recorded Investment	40,112	47,269	680	6,275
Without a related allowance recorded, Interest Income Recognized	298	317	13	76
Impaired Financing Receivable, Average Recorded Investment, Total	40,975	53,148	39,883	54,124
Impaired Financing Receivable, Interest Income Recognized, Total	305	355	541	749
Commercial Real Estate
Financing Receivable, Impaired [Line Items]
With a related allowance recorded, Recorded Investment	0		0		0
With a related allowance recorded, Unpaid Principal Balance	0		0		0
Impaired Financing Receivable, Related Allowance	0		0		0
Without a related allowance recorded, Recorded Investment	6,472		6,472		16,352
Without a related allowance, Unpaid Principal Balance	7,472		7,472		17,654
Without a related allowance recorded, Related Allowance	0		0		0
Impaired Financing Receivable, Recorded Investment	6,472		6,472		16,352
Impaired Financing Receivable, Unpaid Principal Balance, Total	7,472		7,472		17,654
With a related allowance recorded, Average Recorded Investment	0	0	7,028	14,798
With a related allowance recorded, Interest Income Recognized	0	0	70	132
Without a related allowance recorded, Average Recorded Investment	6,934	14,619	0	0
Without a related allowance recorded, Interest Income Recognized	35	64	0	0
Impaired Financing Receivable, Average Recorded Investment, Total	6,934	14,619	7,028	14,798
Impaired Financing Receivable, Interest Income Recognized, Total	35	64	70	132
Commercial and Industrial
Financing Receivable, Impaired [Line Items]
With a related allowance recorded, Recorded Investment	2,443		2,443		964
With a related allowance recorded, Unpaid Principal Balance	2,443		2,443		2,433
Impaired Financing Receivable, Related Allowance	340		340		771
Without a related allowance recorded, Recorded Investment	16,125		16,125		5,902
Without a related allowance, Unpaid Principal Balance	18,097		18,097		7,699
Without a related allowance recorded, Related Allowance	0		0		0
Impaired Financing Receivable, Recorded Investment	18,568		18,568		6,866
Impaired Financing Receivable, Unpaid Principal Balance, Total	20,540		20,540		10,132
With a related allowance recorded, Average Recorded Investment	813	4,617	16,382	11,253
With a related allowance recorded, Interest Income Recognized	6	31	124	189
Without a related allowance recorded, Average Recorded Investment	17,625	10,959	628	4,999
Without a related allowance recorded, Interest Income Recognized	95	98	11	63
Impaired Financing Receivable, Average Recorded Investment, Total	18,438	15,576	17,010	16,252
Impaired Financing Receivable, Interest Income Recognized, Total	101	129	135	252
Commercial Construction
Financing Receivable, Impaired [Line Items]
With a related allowance recorded, Recorded Investment	0		0
With a related allowance recorded, Unpaid Principal Balance	0		0
Impaired Financing Receivable, Related Allowance	0		0
Without a related allowance recorded, Recorded Investment	4,257		4,257		6,613
Without a related allowance, Unpaid Principal Balance	6,295		6,295		10,306
Without a related allowance recorded, Related Allowance	0		0		0
Impaired Financing Receivable, Recorded Investment	4,257		4,257		6,613
Impaired Financing Receivable, Unpaid Principal Balance, Total	6,295		6,295		10,306
With a related allowance recorded, Average Recorded Investment	0	1,232	4,267	10,669
With a related allowance recorded, Interest Income Recognized	0	6	79	108
Without a related allowance recorded, Average Recorded Investment	4,262	10,625	0	1,244
Without a related allowance recorded, Interest Income Recognized	42	48	0	12
Impaired Financing Receivable, Average Recorded Investment, Total	4,262	11,857	4,267	11,913
Impaired Financing Receivable, Interest Income Recognized, Total	42	54	79	120
Consumer Real Estate
Financing Receivable, Impaired [Line Items]
With a related allowance recorded, Recorded Investment	24		24		26
With a related allowance recorded, Unpaid Principal Balance	24		24		26
Impaired Financing Receivable, Related Allowance	24		24		26
Without a related allowance recorded, Recorded Investment	11,106		11,106		12,053
Without a related allowance, Unpaid Principal Balance	12,024		12,024		12,849
Without a related allowance recorded, Related Allowance	0		0		0
Impaired Financing Receivable, Recorded Investment	11,130		11,130		12,079
Impaired Financing Receivable, Unpaid Principal Balance, Total	12,048		12,048		12,875
With a related allowance recorded, Average Recorded Investment	24	29	11,514	11,089
With a related allowance recorded, Interest Income Recognized	1	1	255	243
Without a related allowance recorded, Average Recorded Investment	11,280	11,028	25	30
Without a related allowance recorded, Interest Income Recognized	125	107	1	1
Impaired Financing Receivable, Average Recorded Investment, Total	11,304	11,057	11,539	11,119
Impaired Financing Receivable, Interest Income Recognized, Total	126	108	256	244
Other Consumer
Financing Receivable, Impaired [Line Items]
With a related allowance recorded, Recorded Investment	25		25		1
With a related allowance recorded, Unpaid Principal Balance	25		25		1
Impaired Financing Receivable, Related Allowance	25		25		1
Without a related allowance recorded, Recorded Investment	10		10		24
Without a related allowance, Unpaid Principal Balance	13		13		31
Without a related allowance recorded, Related Allowance	0		0		0
Impaired Financing Receivable, Recorded Investment	35		35		25
Impaired Financing Receivable, Unpaid Principal Balance, Total	38		38		$ 32
With a related allowance recorded, Average Recorded Investment	26	1	12	40
With a related allowance recorded, Interest Income Recognized	0	0	0	1
Without a related allowance recorded, Average Recorded Investment	11	38	27	2
Without a related allowance recorded, Interest Income Recognized	1	0	1	0
Impaired Financing Receivable, Average Recorded Investment, Total	37	39	39	42
Impaired Financing Receivable, Interest Income Recognized, Total	$ 1	$ 0	$ 1	$ 1

Impaired financing receivable with no related allowance.

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Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5258-111524

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- Definition

Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953550-111524

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Amount of allowance for credit losses related to recorded investment.

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Amount of unpaid principal balance of impaired financing receivables with related allowance for credit losses and without related allowance for credit losses.

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5258-111524

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-Publisher FASB
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-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524

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Amount of investment in impaired financing receivables for which there is no related allowance for credit losses.

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