Securities - Investments in Unrealized Loss Position (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Available-for-sale
Fair Value, Less than Twelve Months	$ 227,083	$ 96,572
Gross Unrealized Losses, Less than Twelve Months	(1,409)	(1,895)
Fair Value, Twelve Months or Greater	57,030	28,236
Gross Unrealized Losses, Twelve Months or Greater	(1,859)	(953)
Fair Value, Total	284,113	124,808
Gross Unrealized Losses, Total	(3,268)	(2,848)
Municipals
Held-to-maturity
Held to Maturity, Fair Value, Less than Twelve Months	0	536
Held to Maturity, Gross Unrealized Losses, Less than Twelve Months	0	(19)
Held to Maturity, Fair Value, Twelve Months or Greater	530	0
Held to Maturity, Gross Unrealized Losses, Twelve Months or Greater	(22)	0
Held to Maturity, Fair Value	530	536
Held to Maturity, Gross Unrealized Losses, Total	(22)	(19)
Available-for-sale
Fair Value, Less than Twelve Months	19,115	28,147
Gross Unrealized Losses, Less than Twelve Months	(239)	(1,205)
Fair Value, Twelve Months or Greater	14,228	0
Gross Unrealized Losses, Twelve Months or Greater	(597)	0
Fair Value, Total	33,343	28,147
Gross Unrealized Losses, Total	(836)	(1,205)
U.S. Government agencies
Available-for-sale
Fair Value, Less than Twelve Months	23,545	4,994
Gross Unrealized Losses, Less than Twelve Months	(152)	(112)
Fair Value, Twelve Months or Greater	2,390	0
Gross Unrealized Losses, Twelve Months or Greater	(51)	0
Fair Value, Total	25,935	4,994
Gross Unrealized Losses, Total	(203)	(112)
Mortgage backed securities
Available-for-sale
Fair Value, Less than Twelve Months	180,423	62,145
Gross Unrealized Losses, Less than Twelve Months	(1,017)	(541)
Fair Value, Twelve Months or Greater	33,370	19,768
Gross Unrealized Losses, Twelve Months or Greater	(928)	(623)
Fair Value, Total	213,793	81,913
Gross Unrealized Losses, Total	(1,945)	(1,164)
Asset backed securities
Available-for-sale
Fair Value, Less than Twelve Months	0	1,286
Gross Unrealized Losses, Less than Twelve Months	0	(37)
Fair Value, Twelve Months or Greater	5,652	7,077
Gross Unrealized Losses, Twelve Months or Greater	(173)	(221)
Fair Value, Total	5,652	8,363
Gross Unrealized Losses, Total	(173)	(258)
CRA mutual fund
Available-for-sale
Fair Value, Less than Twelve Months	0	0
Gross Unrealized Losses, Less than Twelve Months	0	0
Fair Value, Twelve Months or Greater	1,390	1,391
Gross Unrealized Losses, Twelve Months or Greater	(110)	(109)
Fair Value, Total	1,390	1,391
Gross Unrealized Losses, Total	(110)	$ (109)
Corporate bonds
Available-for-sale
Fair Value, Less than Twelve Months	4,000
Gross Unrealized Losses, Less than Twelve Months	(1)
Fair Value, Twelve Months or Greater	0
Gross Unrealized Losses, Twelve Months or Greater	0
Fair Value, Total	4,000
Gross Unrealized Losses, Total	$ (1)