Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	$ 863,376	$ 876,796
Unrealized Gains	(23,801)	(21,005)
Unrealized Losses	(3,001)	(6,719)
Securities available-for-sale	884,176	891,082
US Government Agencies Debt Securities [Member]
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	10,570	10,670
Unrealized Gains	(198)	(46)
Unrealized Losses	0	(23)
Securities available-for-sale	10,768	10,693
Mortgage Backed Securities - Residential
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	211,720	208,705
Unrealized Gains	(6,210)	(5,089)
Unrealized Losses	(16)	(630)
Securities available-for-sale	217,914	213,164
Mortgage Backed Securities - Commercial
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	8	9
Unrealized Gains	0	0
Unrealized Losses	0	0
Securities available-for-sale	8	9
Collateralized Mortgage Obligations
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	422,269	441,500
Unrealized Gains	(4,322)	(2,141)
Unrealized Losses	(2,384)	(6,007)
Securities available-for-sale	424,207	437,634
State and Municipal Obligations
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	209,289	206,291
Unrealized Gains	(8,885)	(8,475)
Unrealized Losses	(47)	(59)
Securities available-for-sale	218,127	214,707
Collateralized Debt Obligations
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	9,520	9,621
Unrealized Gains	(4,186)	(5,254)
Unrealized Losses	(554)	0
Securities available-for-sale	$ 13,152	$ 14,875

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
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-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
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-URI http://asc.fasb.org/extlink&oid=66010992&loc=d3e26610-111562

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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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
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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section S99
-Paragraph 1
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