Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	$ 852,434	$ 855,521
Unrealized Gains	(12,312)	(12,618)
Unrealized Losses	(9,065)	(14,414)
Securities available-for-sale	855,681	853,725
US Government Agencies Debt Securities [Member]
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	13,353	13,594
Unrealized Gains	(43)	(32)
Unrealized Losses	(170)	(377)
Securities available-for-sale	13,226	13,249
Mortgage Backed Securities - Residential
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	250,202	261,878
Unrealized Gains	(3,351)	(3,200)
Unrealized Losses	(1,999)	(4,073)
Securities available-for-sale	251,554	261,005
Mortgage Backed Securities - Commercial
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	3	4
Unrealized Gains	0	0
Unrealized Losses	0	0
Securities available-for-sale	3	4
Collateralized Mortgage Obligations
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	359,080	353,499
Unrealized Gains	(1,304)	(1,021)
Unrealized Losses	(5,334)	(6,344)
Securities available-for-sale	355,050	348,176
State and Municipal Obligations
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	220,735	217,365
Unrealized Gains	(4,682)	(3,954)
Unrealized Losses	(1,562)	(2,396)
Securities available-for-sale	223,855	218,923
Collateralized Debt Obligations
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	9,061	9,181
Unrealized Gains	(2,932)	(4,411)
Unrealized Losses	0	(1,224)
Securities available-for-sale	$ 11,993	$ 12,368

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
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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