Allowance for Loan Losses - Investments in Loans Considered to be Impaired and Related Information on Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Financing Receivable, Impaired [Line Items]
With a related allowance recorded, Recorded Investment	$ 9,955		$ 991
With a related allowance recorded, Unpaid Principal Balance	11,546		2,460
Impaired Financing Receivable, Related Allowance	3,567		798
Without a related allowance recorded, Recorded Investment	36,803		40,944
Without a related allowance, Unpaid Principal Balance	43,405		48,539
Without a related allowance recorded, Related Allowance	0		0
Impaired Financing Receivable, Recorded Investment	46,758		41,935
Impaired Financing Receivable, Unpaid Principal Balance, Total	54,951		50,999
With a related allowance recorded, Average Recorded Investment	10,035	$ 6,616
With a related allowance recorded, Interest Income Recognized	72	40
Without a related allowance recorded, Average Recorded Investment	37,944	56,028
Without a related allowance recorded, Interest Income Recognized	242	547
Impaired Financing Receivable, Average Recorded Investment, Total	47,979	62,644
Impaired Financing Receivable, Interest Income Recognized, Total	314	587
Commercial Real Estate
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	8,429		16,352
Without a related allowance, Unpaid Principal Balance	9,773		17,654
Without a related allowance recorded, Related Allowance	0		0
Impaired Financing Receivable, Recorded Investment	8,429		16,352
Impaired Financing Receivable, Unpaid Principal Balance, Total	9,773		17,654
With a related allowance recorded, Average Recorded Investment	0	0
With a related allowance recorded, Interest Income Recognized	0	0
Without a related allowance recorded, Average Recorded Investment	8,581	18,605
Without a related allowance recorded, Interest Income Recognized	33	199
Impaired Financing Receivable, Average Recorded Investment, Total	8,581	18,605
Impaired Financing Receivable, Interest Income Recognized, Total	33	199
Commercial And Industrial
Financing Receivable, Impaired [Line Items]
With a related allowance recorded, Recorded Investment	9,929		964
With a related allowance recorded, Unpaid Principal Balance	11,520		2,433
Impaired Financing Receivable, Related Allowance	3,541		771
Without a related allowance recorded, Recorded Investment	11,115		5,902
Without a related allowance, Unpaid Principal Balance	11,651		7,699
Without a related allowance recorded, Related Allowance	0		0
Impaired Financing Receivable, Recorded Investment	21,044		6,866
Impaired Financing Receivable, Unpaid Principal Balance, Total	23,171		10,132
With a related allowance recorded, Average Recorded Investment	10,008	5,382
With a related allowance recorded, Interest Income Recognized	72	32
Without a related allowance recorded, Average Recorded Investment	11,410	15,513
Without a related allowance recorded, Interest Income Recognized	43	149
Impaired Financing Receivable, Average Recorded Investment, Total	21,418	20,895
Impaired Financing Receivable, Interest Income Recognized, Total	115	181
Commercial Construction
Financing Receivable, Impaired [Line Items]
With a related allowance recorded, Recorded Investment	0
With a related allowance recorded, Unpaid Principal Balance	0
Impaired Financing Receivable, Related Allowance	0
Without a related allowance recorded, Recorded Investment	5,903		6,613
Without a related allowance, Unpaid Principal Balance	9,773		10,306
Without a related allowance recorded, Related Allowance	0		0
Impaired Financing Receivable, Recorded Investment	5,903		6,613
Impaired Financing Receivable, Unpaid Principal Balance, Total	9,773		10,306
With a related allowance recorded, Average Recorded Investment	0	1,117
With a related allowance recorded, Interest Income Recognized	0	6
Without a related allowance recorded, Average Recorded Investment	6,239	10,782
Without a related allowance recorded, Interest Income Recognized	37	64
Impaired Financing Receivable, Average Recorded Investment, Total	6,239	11,899
Impaired Financing Receivable, Interest Income Recognized, Total	37	70
Consumer Real Estate
Financing Receivable, Impaired [Line Items]
With a related allowance recorded, Recorded Investment	25		26
With a related allowance recorded, Unpaid Principal Balance	25		26
Impaired Financing Receivable, Related Allowance	25		26
Without a related allowance recorded, Recorded Investment	11,335		12,053
Without a related allowance, Unpaid Principal Balance	12,185		12,849
Without a related allowance recorded, Related Allowance	0		0
Impaired Financing Receivable, Recorded Investment	11,360		12,079
Impaired Financing Receivable, Unpaid Principal Balance, Total	12,210		12,875
With a related allowance recorded, Average Recorded Investment	26	115
With a related allowance recorded, Interest Income Recognized	0	2
Without a related allowance recorded, Average Recorded Investment	11,692	11,102
Without a related allowance recorded, Interest Income Recognized	129	135
Impaired Financing Receivable, Average Recorded Investment, Total	11,718	11,217
Impaired Financing Receivable, Interest Income Recognized, Total	129	137
Other Consumer
Financing Receivable, Impaired [Line Items]
With a related allowance recorded, Recorded Investment	1		1
With a related allowance recorded, Unpaid Principal Balance	1		1
Impaired Financing Receivable, Related Allowance	1		1
Without a related allowance recorded, Recorded Investment	21		24
Without a related allowance, Unpaid Principal Balance	23		31
Without a related allowance recorded, Related Allowance	0		0
Impaired Financing Receivable, Recorded Investment	22		25
Impaired Financing Receivable, Unpaid Principal Balance, Total	24		$ 32
With a related allowance recorded, Average Recorded Investment	1	2
With a related allowance recorded, Interest Income Recognized	0	0
Without a related allowance recorded, Average Recorded Investment	22	26
Without a related allowance recorded, Interest Income Recognized	0	0
Impaired Financing Receivable, Average Recorded Investment, Total	23	28
Impaired Financing Receivable, Interest Income Recognized, Total	$ 0	$ 0

Impaired financing receivable with no related allowance.

No definition available.

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- Definition

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+ References

No definition available.

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- Definition

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=66008989&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=66008989&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.

+ References

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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 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953550-111524

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- Definition

Amount of allowance for credit losses related to recorded investment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Recorded Investment
-URI http://asc.fasb.org/extlink&oid=65880944

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
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-Section 50
-Paragraph 15
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-URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5212-111524

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- Definition

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

+ References

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Amount of average investment of impaired financing receivables for which there is no 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 17
-URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5258-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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Amount of interest income, recognized on accrual basis, on financing receivables that are recognized as impaired, for which there is no related allowance for credit losses.

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Amount of interest income, recognized on accrual basis, on financing receivables, for which there is a related allowance for credit losses and are recognized as impaired.

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Unpaid principal balance of impaired financing receivables for which there is a related allowance for credit losses.

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