Investment Securities - Unrealized Gain (Loss) on Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	$ 76,566	$ 192,171
Less than 12 months, unrealized losses	175	1,084
More than 12 months, fair value	95,892	3,313
More than 12 months, unrealized losses	572	29
Fair Value	172,458	195,484
Unrealized Losses	747	1,113
Schedule of Held-to-maturity Securities [Line Items]
Less than 12 months, fair value	856
Less than 12 months, unrealized losses	1
More than 12 months, fair value	0
More than 12 months, unrealized losses	0
Fair Value	856
Unrealized Losses	1
U.S. Treasury and government sponsored entities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	74,192	180,638
Less than 12 months, unrealized losses	157	1,051
More than 12 months, fair value	92,878	489
More than 12 months, unrealized losses	551	5
Fair Value	167,070	181,127
Unrealized Losses	708	1,056
Municipal securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	1,344	11,533
Less than 12 months, unrealized losses	7	33
More than 12 months, fair value	3,014	1,786
More than 12 months, unrealized losses	21	20
Fair Value	4,358	13,319
Unrealized Losses	28	53
Preferred Stock
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, fair value	1,030	0
Less than 12 months, unrealized losses	11	0
More than 12 months, fair value	0	1,038
More than 12 months, unrealized losses	0	4
Fair Value	1,030	1,038
Unrealized Losses	11	$ 4
Municipal securities
Schedule of Held-to-maturity Securities [Line Items]
Less than 12 months, fair value	856
Less than 12 months, unrealized losses	1
More than 12 months, fair value	0
More than 12 months, unrealized losses	0
Fair Value	856
Unrealized Losses	$ 1

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.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
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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.

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