Investment Securities, Available-for-sale Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Amortized cost and fair value of the securities available for sale [Abstract]
Amortized Cost	$ 586,235	$ 631,625
Gross Unrealized Gains	269	136
Gross Unrealized Losses	6,074	11,401
Fair Value	580,430	620,360
U. S. Government Sponsored Enterprises [Member]
Amortized cost and fair value of the securities available for sale [Abstract]
Amortized Cost	125,024	119,887
Gross Unrealized Gains	93	0
Gross Unrealized Losses	1,459	2,621
Fair Value	123,658	117,266
State and Political Subdivisions [Member]
Amortized cost and fair value of the securities available for sale [Abstract]
Amortized Cost	521	873
Gross Unrealized Gains	12	13
Gross Unrealized Losses	0	0
Fair Value	533	886
Corporate Bonds [Member]
Amortized cost and fair value of the securities available for sale [Abstract]
Amortized Cost	40,442	40,956
Gross Unrealized Gains	0	0
Gross Unrealized Losses	61	251
Fair Value	40,381	40,705
Mortgage Backed Securities and Collateralized Mortgage Obligations-Residential [Member]
Amortized cost and fair value of the securities available for sale [Abstract]
Amortized Cost	338,519	378,068
Gross Unrealized Gains	164	123
Gross Unrealized Losses	3,152	5,883
Fair Value	335,531	372,308
Small Business Administration-Guaranteed Participation Securities [Member]
Amortized cost and fair value of the securities available for sale [Abstract]
Amortized Cost	71,169	81,026
Gross Unrealized Gains	0	0
Gross Unrealized Losses	1,351	2,527
Fair Value	69,818	78,499
Mortgage Backed Securities and Collateralized Mortgage Obligations-Commercial [Member]
Amortized cost and fair value of the securities available for sale [Abstract]
Amortized Cost	9,875	10,130
Gross Unrealized Gains	0	0
Gross Unrealized Losses	51	119
Fair Value	9,824	10,011
Other [Member]
Amortized cost and fair value of the securities available for sale [Abstract]
Amortized Cost	650	650
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	650	650
Debt Securities [Member]
Amortized cost and fair value of the securities available for sale [Abstract]
Amortized Cost	586,200	631,590
Gross Unrealized Gains	269	136
Gross Unrealized Losses	6,074	11,401
Fair Value	580,395	620,325
Equity Securities [Member]
Amortized cost and fair value of the securities available for sale [Abstract]
Amortized Cost	35	35
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	$ 35	$ 35

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=75030427&loc=d3e22054-111558

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27232-111563

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=82896770&loc=d3e26610-111562

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
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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.

+ References

Reference 1: 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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-Subparagraph (c)
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+ 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 210.5-02.2)
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