Securities - HTM Contractual Maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
HTM, Amortized Cost, Rolling Maturities
Due in one year or less	$ 3,798
Due after one year through five years	4,333
Due after five years through ten years	26,293
Due after ten years	48,080
Total	82,504
Amortized cost	351,831	$ 332,022
HTM, Fair Value, Rolling Maturities
Due in one year or less	3,810
Due after one year through five years	4,326
Due after five years through ten years	25,563
Due after ten years	45,790
Total	79,489
Fair Value	345,088	331,468
Residential mortgage-backed Securities
HTM, Amortized Cost, Rolling Maturities
Mortgage-backed securities, collateralized mortgage obligations and commercial mortgage-backed securities	19,606
Amortized cost	19,606	23,735
HTM, Fair Value, Rolling Maturities
Mortgage-backed securities, collateralized mortgage obligations and commercial mortgage-backed securities	19,613
Fair Value	19,613	24,046
Collateralized mortgage obligations
HTM, Amortized Cost, Rolling Maturities
Mortgage-backed securities, collateralized mortgage obligations and commercial mortgage-backed securities	217,954
Amortized cost	217,954	167,541
HTM, Fair Value, Rolling Maturities
Mortgage-backed securities, collateralized mortgage obligations and commercial mortgage-backed securities	214,710
Fair Value	214,710	$ 166,873
Commercial mortgage-backed Securities
HTM, Amortized Cost, Rolling Maturities
Mortgage-backed securities, collateralized mortgage obligations and commercial mortgage-backed securities	31,767
HTM, Fair Value, Rolling Maturities
Mortgage-backed securities, collateralized mortgage obligations and commercial mortgage-backed securities	$ 31,276