Investment Securities - Schedule of Amortized Cost and Fair Value of Debt Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Schedule Of Available For Sale Securities [Line Items]
Amortized cost, Due in one year or less	$ 9,290	$ 6,849
Amortized cost, Due in one to five	25,520	44,108
Amortized cost, Due in five to ten years	31,122	29,964
Amortized cost, Due in over ten years	62,909	32,692
Amortized cost, Total	128,841	113,613
Total debt securities, Amortized cost	579,715	637,754
Fair value, Due in one year or less	9,352	6,886
Fair value, Due in one to five	26,340	44,358
Fair value, Due in five to ten years	32,248	31,927
Fair value, Due in over ten years	61,725	34,959
Fair value, Total	129,665	118,130
Total debt securities, Fair value	573,573	640,503
Mortgage-backed Securities - Residential
Schedule Of Available For Sale Securities [Line Items]
Total debt securities, Amortized cost	450,874	524,141
Total debt securities, Fair value	$ 443,908	$ 522,373