Securities, Amortized Cost and Fair Value of Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Available-for-sale, amortized cost [Abstract]
Due in one year or less	$ 104,396
Due after one through five years	101,799
Due after five through ten years	60,047
Due after ten years	90,123
U.S. government sponsored agency mortgage-backed securities	227,574
Amortized cost	583,939	$ 568,381
CRA investment funds	25,000
Amortized cost	608,939	593,381
Available-for-sale, fair value [Abstract]
Due in one year or less	104,383
Due after one through five years	102,135
Due after five through ten years	60,358
Due after ten years	89,104
U.S. government sponsored agency mortgage-backed securities	225,056
Total debt securities	581,036	570,185
CRA investment funds	24,358
Total securities	605,394	594,936
Held-to-maturity, amortized cost [Abstract]
Due in one year or less	0
Due after one through five years	866
Due after five through ten years	0
Due after ten years	0
U.S. government sponsored agency mortgage-backed securities	0
Amortized cost	866	1,661
CRA investment funds	0
Total securities	866
Held-to-maturity, fair value [Abstract]
Due in one year or less	0
Due after one through five years	867
Due after five through ten years	0
Due after ten years	0
U.S. government sponsored agency mortgage-backed securities	0
Total debt securities	867	$ 1,651
CRA investment funds	0
Total securities	$ 867