Investment Securities - Summary of Amortized Cost of Securities and Fair Values (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Schedule Of Available For Sale Securities [Line Items]
Amortized cost	$ 588,459	$ 646,725
Gross unrealized gains	3,943	8,570
Gross unrealized losses	(10,219)	(5,908)
Available-for-sale securities, at fair value	582,183	649,387
Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized cost	579,715	637,754
Gross unrealized gains	3,942	8,567
Gross unrealized losses	(10,084)	(5,818)
Available-for-sale securities, at fair value	573,573	640,503
Debt Securities \| U.S. Government Agency Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized cost	998	34,161
Gross unrealized losses	(13)	(353)
Available-for-sale securities, at fair value	985	33,808
Debt Securities \| Mortgage-backed Securities - Residential
Schedule Of Available For Sale Securities [Line Items]
Amortized cost	450,874	524,141
Gross unrealized gains	939	3,675
Gross unrealized losses	(7,905)	(5,443)
Available-for-sale securities, at fair value	443,908	522,373
Debt Securities \| Municipals, Tax Exempt
Schedule Of Available For Sale Securities [Line Items]
Amortized cost	116,034	74,945
Gross unrealized gains	3,003	4,892
Gross unrealized losses	(2,114)
Available-for-sale securities, at fair value	116,923	79,837
Debt Securities \| Treasury Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized cost	11,809	4,507
Gross unrealized losses	(52)	(22)
Available-for-sale securities, at fair value	11,757	4,485
Equity Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized cost	8,744	8,971
Gross unrealized gains	1	3
Gross unrealized losses	(135)	(90)
Available-for-sale securities, at fair value	$ 8,610	$ 8,884

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 25
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=65884222&loc=d3e22054-111558

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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-Section 50
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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-Publisher FASB
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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section S99
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