Investment Securities - Schedule of Gross Unrealized Losses (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2017	Dec. 31, 2016
Schedule Of Available For Sale Securities [Line Items]
Fair Value, Less than 12 months	$ 429,969	$ 444,968
Unrealized Loss, Less than 12 months	8,543	9,409
Fair Value, 12 months or more	21,528	22,199
Unrealized Loss, 12 months or more	804	810
Fair Value, Total	451,497	467,167
Unrealized Losses, Total	9,347	10,219
Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Fair Value, Less than 12 months	429,969	444,968
Unrealized Loss, Less than 12 months	8,543	9,409
Fair Value, 12 months or more	18,523	19,073
Unrealized Loss, 12 months or more	664	675
Fair Value, Total	448,492	464,041
Unrealized Losses, Total	9,207	10,084
Debt Securities \| U.S. Government Agency Securities
Schedule Of Available For Sale Securities [Line Items]
Fair Value, Less than 12 months	987	985
Unrealized Loss, Less than 12 months	12	13
Fair Value, Total	987	985
Unrealized Losses, Total	12	13
Debt Securities \| Mortgage-backed Securities - Residential
Schedule Of Available For Sale Securities [Line Items]
Fair Value, Less than 12 months	376,680	390,595
Unrealized Loss, Less than 12 months	6,730	7,230
Fair Value, 12 months or more	18,307	19,073
Unrealized Loss, 12 months or more	650	675
Fair Value, Total	394,987	409,668
Unrealized Losses, Total	7,380	7,905
Debt Securities \| Municipals, Tax Exempt
Schedule Of Available For Sale Securities [Line Items]
Fair Value, Less than 12 months	40,529	43,132
Unrealized Loss, Less than 12 months	1,757	2,114
Fair Value, 12 months or more	216
Unrealized Loss, 12 months or more	14
Fair Value, Total	40,745	43,132
Unrealized Losses, Total	1,771	2,114
Debt Securities \| Treasury Securities
Schedule Of Available For Sale Securities [Line Items]
Fair Value, Less than 12 months	11,773	10,256
Unrealized Loss, Less than 12 months	44	52
Fair Value, Total	11,773	10,256
Unrealized Losses, Total	44	52
Equity Securities
Schedule Of Available For Sale Securities [Line Items]
Fair Value, 12 months or more	3,005	3,126
Unrealized Loss, 12 months or more	140	135
Fair Value, Total	3,005	3,126
Unrealized Losses, Total	$ 140	$ 135

Amount of unrealized loss on securities classified as available-for-sale that have been in a loss position for twelve months or longer.

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Amount of unrealized loss on securities classified as available-for-sale.

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Amount of unrealized loss on investments in available-for-sale securities that have been in a loss position for less than twelve months.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27290-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27337-111563

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This item represents the aggregate fair value of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for less than twelve months.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27337-111563

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27290-111563

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-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27337-111563

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