Investment Securities Available-for-sale (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016
Amortized cost	$ 499,405	$ 541,364
Gross unrealized gains	2,682	2,648
Gross unrealized losses	4,415	5,904
Estimated fair value	497,672	538,108	$ 409,512
US Government Agencies Debt Securities [Member]
Amortized cost	146,873	107,425
Gross unrealized gains	360	519
Gross unrealized losses	1,371	1,802
Estimated fair value	145,862	106,142
Residential Mortgage Backed Securities [Member]
Amortized cost	299,136	329,606
Gross unrealized gains	449	324
Gross unrealized losses	3,044	3,691
Estimated fair value	296,541	326,239
US States and Political Subdivisions Debt Securities [Member]
Amortized cost	43,166	94,607
Gross unrealized gains	1,720	1,723
Gross unrealized losses		400
Estimated fair value	44,886	95,930
Corporate Debt Securities [Member]
Amortized cost	10,012	9,508
Gross unrealized gains	153	82
Gross unrealized losses		11
Estimated fair value	10,165	9,579
Investment Securities [Member]
Amortized cost	218	218
Estimated fair value	$ 218	$ 218

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
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-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
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82897076&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
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-Section 50
-Paragraph 2
-Subparagraph (c)
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This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ 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)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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