Investment Securities, Available-for-sale Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Amortized cost and fair value of the securities available for sale [Abstract]
Amortized Cost	$ 616,058	$ 608,521
Gross Unrealized Gains	4,534	469
Gross Unrealized Losses	86	7,953
Fair Value	620,506	601,037
U. S. Government Sponsored Enterprises [Member]
Amortized cost and fair value of the securities available for sale [Abstract]
Amortized Cost	116,505	86,899
Gross Unrealized Gains	90	19
Gross Unrealized Losses	0	181
Fair Value	116,595	86,737
State and Political Subdivisions [Member]
Amortized cost and fair value of the securities available for sale [Abstract]
Amortized Cost	955	1,270
Gross Unrealized Gains	19	20
Gross Unrealized Losses	0	0
Fair Value	974	1,290
Mortgage Backed Securities and Collateralized Mortgage Obligations-Residential [Member]
Amortized cost and fair value of the securities available for sale [Abstract]
Amortized Cost	400,527	416,625
Gross Unrealized Gains	3,625	430
Gross Unrealized Losses	14	5,326
Fair Value	404,138	411,729
Small Business Administration-Guaranteed Participation Securities [Member]
Amortized cost and fair value of the securities available for sale [Abstract]
Amortized Cost	87,102	92,620
Gross Unrealized Gains	710	0
Gross Unrealized Losses	72	2,204
Fair Value	87,740	90,416
Mortgage Backed Securities and Collateralized Mortgage Obligations-Commercial [Member]
Amortized cost and fair value of the securities available for sale [Abstract]
Amortized Cost	10,284	10,422
Gross Unrealized Gains	90	0
Gross Unrealized Losses	0	242
Fair Value	10,374	10,180
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	616,023	608,486
Gross Unrealized Gains	4,534	469
Gross Unrealized Losses	86	7,953
Fair Value	620,471	601,002
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=65884222&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=73527792&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=66010992&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
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27161-111563

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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
-SubTopic 10
-Section 50
-Paragraph 2
-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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