Investment Securities - Unrealized Gain (Loss) on Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	$ 176,861	$ 192,171
Less than 12 months, unrealized losses	793	1,084
More than 12 months, fair value	3,309	3,313
More than 12 months, unrealized losses	30	29
Fair Value	180,170	195,484
Unrealized Losses	823	1,113
U.S. Treasury and government sponsored entities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	172,627	180,638
Less than 12 months, unrealized losses	784	1,051
More than 12 months, fair value	489	489
More than 12 months, unrealized losses	6	5
Fair Value	173,116	181,127
Unrealized Losses	790	1,056
Municipal securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	4,234	11,533
Less than 12 months, unrealized losses	9	33
More than 12 months, fair value	1,784	1,786
More than 12 months, unrealized losses	19	20
Fair Value	6,018	13,319
Unrealized Losses	28	53
Preferred stock
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	0	0
Less than 12 months, unrealized losses	0	0
More than 12 months, fair value	1,036	1,038
More than 12 months, unrealized losses	5	4
Fair Value	1,036	1,038
Unrealized Losses	$ 5	$ 4

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for twelve months or longer.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27290-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale in a continuous loss position.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27337-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Publisher FASB
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-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27290-111563

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