Investment Securities - Summary of Unrealized Losses of Available-for-Sale Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale, Securities with losses under 12 months, Fair Value	$ 204,059	$ 232,776
Available-for-sale, Securities with losses under 12 months, Gross Unrealized Loss	3,961	4,466
Available-for-sale, Securities with losses over 12 months, Fair Value	14,042	16,315
Available-for-sale, Securities with losses over 12 months, Gross Unrealized Loss	411	556
Available-for-sale, Total, Fair Value	218,101	249,091
Available-for-sale, Total, Gross Unrealized Loss	4,372	5,022
Obligations of state and political subdivisions
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale, Securities with losses under 12 months, Fair Value	12,827	13,402
Available-for-sale, Securities with losses under 12 months, Gross Unrealized Loss	968	1,020
Available-for-sale, Securities with losses over 12 months, Fair Value	0	0
Available-for-sale, Securities with losses over 12 months, Gross Unrealized Loss	0	0
Available-for-sale, Total, Fair Value	12,827	13,402
Available-for-sale, Total, Gross Unrealized Loss	968	1,020
GSE mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale, Securities with losses under 12 months, Fair Value	26,478	29,119
Available-for-sale, Securities with losses under 12 months, Gross Unrealized Loss	146	302
Available-for-sale, Securities with losses over 12 months, Fair Value	0	0
Available-for-sale, Securities with losses over 12 months, Gross Unrealized Loss	0	0
Available-for-sale, Total, Fair Value	26,478	29,119
Available-for-sale, Total, Gross Unrealized Loss	146	302
Collateralized mortgage obligations: residential
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale, Securities with losses under 12 months, Fair Value	162,695	187,235
Available-for-sale, Securities with losses under 12 months, Gross Unrealized Loss	2,806	3,099
Available-for-sale, Securities with losses over 12 months, Fair Value	11,051	14,194
Available-for-sale, Securities with losses over 12 months, Gross Unrealized Loss	375	507
Available-for-sale, Total, Fair Value	173,746	201,429
Available-for-sale, Total, Gross Unrealized Loss	3,181	3,606
Collateralized mortgage obligations: commercial
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale, Securities with losses under 12 months, Fair Value	0	961
Available-for-sale, Securities with losses under 12 months, Gross Unrealized Loss	0	4
Available-for-sale, Securities with losses over 12 months, Fair Value	2,991	2,121
Available-for-sale, Securities with losses over 12 months, Gross Unrealized Loss	36	49
Available-for-sale, Total, Fair Value	2,991	3,082
Available-for-sale, Total, Gross Unrealized Loss	36	53
Mutual funds
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale, Securities with losses under 12 months, Fair Value	2,059	2,059
Available-for-sale, Securities with losses under 12 months, Gross Unrealized Loss	41	41
Available-for-sale, Securities with losses over 12 months, Fair Value	0	0
Available-for-sale, Securities with losses over 12 months, Gross Unrealized Loss	0	0
Available-for-sale, Total, Fair Value	2,059	2,059
Available-for-sale, Total, Gross Unrealized Loss	$ 41	$ 41