Securities, Amortized Cost and Fair Value of Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Available-for-sale, amortized cost [Abstract]
Due in one year or less	$ 69,248
Due after one through five years	148,439
Due after five through ten years	59,494
Due after ten years	86,776
U.S. government sponsored agency mortgage-backed securities	219,166
Amortized cost	583,123	$ 583,939
CRA investment funds	25,000
Amortized cost	608,123	608,939
Available-for-sale, fair value [Abstract]
Due in one year or less	69,205
Due after one through five years	149,115
Due after five through ten years	60,236
Due after ten years	86,084
U.S. government sponsored agency mortgage-backed securities	216,703
Total debt securities	581,343	581,036
CRA investment funds	24,358
Total securities	605,701	605,394
Held-to-maturity, amortized cost [Abstract]
Due in one year or less	0
Due after one through five years	858
Due after five through ten years	0
Due after ten years	0
U.S. government sponsored agency mortgage-backed securities	0
Amortized cost	858	866
CRA investment funds	0
Total securities	858
Held-to-maturity, fair value [Abstract]
Due in one year or less	0
Due after one through five years	858
Due after five through ten years	0
Due after ten years	0
U.S. government sponsored agency mortgage-backed securities	0
Total debt securities	858	$ 867
CRA investment funds	0
Total securities	$ 858