Investment Securities, Available-for-sale Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Amortized cost and fair value of the securities available for sale [Abstract]
Amortized Cost	$ 608,521	$ 682,913
Gross Unrealized Gains	469	1,149
Gross Unrealized Losses	7,953	7,303
Fair value	601,037	676,759
U. S. Government Sponsored Enterprises [Member]
Amortized cost and fair value of the securities available for sale [Abstract]
Amortized Cost	86,899	78,420
Gross Unrealized Gains	19	2
Gross Unrealized Losses	181	622
Fair value	86,737	77,800
State and Political Subdivisions [Member]
Amortized cost and fair value of the securities available for sale [Abstract]
Amortized Cost	1,270	2,232
Gross Unrealized Gains	20	39
Gross Unrealized Losses	0	0
Fair value	1,290	2,271
Mortgage-Backed Securities and Collateralized Mortgage Obligations-Residential [Member]
Amortized cost and fair value of the securities available for sale [Abstract]
Amortized Cost	416,625	486,107
Gross Unrealized Gains	430	1,108
Gross Unrealized Losses	5,326	3,655
Fair value	411,729	483,560
Corporate Bonds [Member]
Amortized cost and fair value of the securities available for sale [Abstract]
Amortized Cost		1,500
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Fair value		1,500
Small Business Administration-Guaranteed Participation Securities [Member]
Amortized cost and fair value of the securities available for sale [Abstract]
Amortized Cost	92,620	103,273
Gross Unrealized Gains	0	0
Gross Unrealized Losses	2,204	2,777
Fair value	90,416	100,496
Mortgage-Backed Securities and Collateralized Mortgage Obligations-Commercial [Member]
Amortized cost and fair value of the securities available for sale [Abstract]
Amortized Cost	10,422	10,696
Gross Unrealized Gains	0	0
Gross Unrealized Losses	242	249
Fair value	10,180	10,447
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	608,486	682,878
Gross Unrealized Gains	469	1,149
Gross Unrealized Losses	7,953	7,303
Fair value	601,002	676,724
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=51813488&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=27724398&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=49167202&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=27724398&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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