Investment Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016
Securities Available for Sale, Gross Unrealized Losses
Less Than Twelve Months	$ 7,210	$ 8,184	$ 147
Twelve Months or More	362	424	366
Securities Available for Sale, Fair Value
Less Than Twelve Months	700,546	688,376	53,362
Twelve Months or More	3,391	3,453	21,131
State and municipal obligations
Securities Available for Sale, Gross Unrealized Losses
Less Than Twelve Months	140	190	16
Twelve Months or More			62
Securities Available for Sale, Fair Value
Less Than Twelve Months	10,984	11,506	1,271
Twelve Months or More			1,038
Government-sponsored entities debt
Securities Available for Sale, Gross Unrealized Losses
Less Than Twelve Months	721	846	108
Twelve Months or More			35
Securities Available for Sale, Fair Value
Less Than Twelve Months	87,609	84,642	36,611
Twelve Months or More			9,956
Mortgage-backed securities.
Securities Available for Sale, Gross Unrealized Losses
Less Than Twelve Months	6,349	7,148	23
Twelve Months or More	71	77	88
Securities Available for Sale, Fair Value
Less Than Twelve Months	601,953	592,228	15,480
Twelve Months or More	1,940	2,058	8,575
Common Stock
Securities Available for Sale, Gross Unrealized Losses
Twelve Months or More	291	347	181
Securities Available for Sale, Fair Value
Twelve Months or More	$ 1,451	$ 1,395	$ 1,562

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for twelve months or longer.

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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Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for less than twelve months.

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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

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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-Section 50
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-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27290-111563

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

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