Premises and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Property Plant And Equipment Line Items
Property Plant And Equipment Gross	$ 135,587	$ 130,582
Accumulated depreciation and amortization	(67,727)	(60,175)
Total Premises and Equipment, net	67,860	70,407
Land And Land Improvements
Property Plant And Equipment Line Items
Property Plant And Equipment Gross	$ 5,638	5,638
Land And Land Improvements \| Minimum [Member]
Property Plant And Equipment Line Items
Property Plant And Equipment Useful Life	0 years
Land And Land Improvements \| Maximum [Member]
Property Plant And Equipment Line Items
Property Plant And Equipment Useful Life	0 years
Building And Building Improvements
Property Plant And Equipment Line Items
Property Plant And Equipment Gross	$ 64,277	64,048
Building And Building Improvements \| Minimum [Member]
Property Plant And Equipment Line Items
Property Plant And Equipment Useful Life	0 years
Building And Building Improvements \| Maximum [Member]
Property Plant And Equipment Line Items
Property Plant And Equipment Useful Life	40 years
Leasehold Improvements
Property Plant And Equipment Line Items
Property Plant And Equipment Gross	$ 20,647	20,414
Leasehold Improvements \| Minimum [Member]
Property Plant And Equipment Line Items
Property Plant And Equipment Useful Life	5 years
Leasehold Improvements \| Maximum [Member]
Property Plant And Equipment Line Items
Property Plant And Equipment Useful Life	10 years
Furniture And Fixtures
Property Plant And Equipment Line Items
Property Plant And Equipment Gross	$ 16,242	14,479
Furniture And Fixtures \| Minimum [Member]
Property Plant And Equipment Line Items
Property Plant And Equipment Useful Life	3 years
Furniture And Fixtures \| Maximum [Member]
Property Plant And Equipment Line Items
Property Plant And Equipment Useful Life	7 years
Software And Software Development Costs
Property Plant And Equipment Line Items
Property Plant And Equipment Gross	$ 28,783	$ 26,003
Software And Software Development Costs \| Minimum [Member]
Property Plant And Equipment Line Items
Property Plant And Equipment Useful Life	3 years
Software And Software Development Costs \| Maximum [Member]
Property Plant And Equipment Line Items
Property Plant And Equipment Useful Life	7 years

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.14)
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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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+ References

No definition available.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(13))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(14))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section S99
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-Subparagraph (SX 210.7-03(a)(8))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 4: http://www.xbrl.org/2003/role/presentationRef
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-Topic 360
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-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

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- Definition

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References

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