Securities - Amortized Cost and Fair Value (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 30, 2017	Dec. 31, 2016
Available-for-sale Securities [Abstract]
Available-for-sale, Amortized Cost	$ 697,245	$ 697,245	$ 275,734
Gross Unrealized Gains	1,459	1,459	566
Gross Unrealized Losses	(4,445)	(4,445)	(1,681)
Available-for-sale securities, at fair value	694,259	694,259	274,619
Held-to-maturity Securities [Abstract]
Held-to-maturity, Amortized Cost	13,730	13,730	35,505
Gross Unrealized Gains	102	102	142
Gross Unrealized Losses	(131)	(131)	(803)
Held-to-maturity, fair value (in dollars)	13,701	13,701	34,844
Additional Information Abstract
Sale of available for sale securities		349,374
Available-for-sale Securities, Gross Realized Gains		910
Available-for-sale Securities, Gross Realized Losses		948
Available-for-sale Securities, Gross Realized Gain (Loss)	(332)	(38)
SBA guaranteed securities
Available-for-sale Securities [Abstract]
Available-for-sale, Amortized Cost	106,284	106,284
Gross Unrealized Gains	252	252
Gross Unrealized Losses	(350)	(350)
Available-for-sale securities, at fair value	106,186	106,186
US Treasury and Government
Available-for-sale Securities [Abstract]
Available-for-sale, Amortized Cost			118,272
Gross Unrealized Gains			17
Gross Unrealized Losses			(403)
Available-for-sale securities, at fair value			117,886
Commercial
Available-for-sale Securities [Abstract]
Available-for-sale, Amortized Cost	66,069	66,069
Gross Unrealized Losses	(611)	(611)
Available-for-sale securities, at fair value	65,458	65,458
Residential
Available-for-sale Securities [Abstract]
Available-for-sale, Amortized Cost	259,045	259,045	99,876
Gross Unrealized Gains	1,197	1,197	452
Gross Unrealized Losses	(307)	(307)	(430)
Available-for-sale securities, at fair value	259,935	259,935	99,898
Held-to-maturity Securities [Abstract]
Held-to-maturity, Amortized Cost	11,103	11,103	14,358
Gross Unrealized Gains	97	97	140
Gross Unrealized Losses	(131)	(131)	(267)
Held-to-maturity, fair value (in dollars)	11,069	11,069	14,231
Commercial
Available-for-sale Securities [Abstract]
Available-for-sale, Amortized Cost	31,138	31,138
Gross Unrealized Losses	(30)	(30)
Available-for-sale securities, at fair value	31,108	31,108
Residential
Available-for-sale Securities [Abstract]
Available-for-sale, Amortized Cost	214,898	214,898	42,379
Gross Unrealized Gains			96
Gross Unrealized Losses	(2,921)	(2,921)	(563)
Available-for-sale securities, at fair value	211,977	211,977	41,912
Held-to-maturity Securities [Abstract]
Held-to-maturity, Amortized Cost	2,627	2,627	21,147
Gross Unrealized Gains	5	5	2
Gross Unrealized Losses			(536)
Held-to-maturity, fair value (in dollars)	2,632	2,632	20,613
Corporate debt securities
Available-for-sale Securities [Abstract]
Available-for-sale, Amortized Cost	1,788	1,788	3,788
Gross Unrealized Gains	3	3	1
Gross Unrealized Losses			(14)
Available-for-sale securities, at fair value	1,791	1,791	3,775
Obligations of municipal subdivisions
Available-for-sale Securities [Abstract]
Available-for-sale, Amortized Cost	6,686	6,686	236
Gross Unrealized Gains	7	7
Gross Unrealized Losses			(1)
Available-for-sale securities, at fair value	6,693	6,693	235
CRA qualified investment fund
Available-for-sale Securities [Abstract]
Available-for-sale, Amortized Cost	11,337	11,337	11,183
Gross Unrealized Losses	(226)	(226)	(270)
Available-for-sale securities, at fair value	$ 11,111	$ 11,111	$ 10,913

n/a

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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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.

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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.

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This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities.

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