Securities - HTM Contractual Maturities (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
HTM, Amortized Cost, Rolling Maturities
Due in one year or less	$ 4,286
Due after one year through five years	3,325
Due after five years through ten years	26,290
Due after ten years	47,959
Total	81,860
Amortized cost	337,357	$ 351,831
HTM, Fair Value, Rolling Maturities
Due in one year or less	4,297
Due after one year through five years	3,348
Due after five years through ten years	25,618
Due after ten years	45,924
Total	79,187
Fair Value	331,387	345,088
Residential mortgage-backed Securities
HTM, Amortized Cost, Rolling Maturities
Mortgage-backed securities, collateralized mortgage obligations and commercial mortgage-backed securities	18,717
Amortized cost	18,717	19,606
HTM, Fair Value, Rolling Maturities
Mortgage-backed securities, collateralized mortgage obligations and commercial mortgage-backed securities	18,834
Fair Value	18,834	19,613
Collateralized mortgage obligations
HTM, Amortized Cost, Rolling Maturities
Mortgage-backed securities, collateralized mortgage obligations and commercial mortgage-backed securities	205,176
Amortized cost	205,176	217,954
HTM, Fair Value, Rolling Maturities
Mortgage-backed securities, collateralized mortgage obligations and commercial mortgage-backed securities	202,214
Fair Value	202,214	$ 214,710
Commercial mortgage-backed Securities
HTM, Amortized Cost, Rolling Maturities
Mortgage-backed securities, collateralized mortgage obligations and commercial mortgage-backed securities	31,604
HTM, Fair Value, Rolling Maturities
Mortgage-backed securities, collateralized mortgage obligations and commercial mortgage-backed securities	$ 31,152