Investment Securities - Summary of Unrealized Losses of Held-to-Maturity Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity, Securities with losses under 12 months, Fair Value	$ 32,273	$ 19,360
Held-to-maturity, Securities with losses under 12 months, Gross Unrealized Loss	234	208
Held-to-maturity, Securities with losses over 12 months, Fair Value	20,256	33,635
Held-to-maturity, Securities with losses over 12 months, Gross Unrealized Loss	598	800
Held-to-maturity, Total, Fair Value	52,529	52,995
Held-to-maturity, Total, Gross Unrealized Loss	832	1,008
Obligations of state and political subdivisions
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity, Securities with losses under 12 months, Fair Value	18,319	11,761
Held-to-maturity, Securities with losses under 12 months, Gross Unrealized Loss	220	35
Held-to-maturity, Securities with losses over 12 months, Fair Value	1,295	13,263
Held-to-maturity, Securities with losses over 12 months, Gross Unrealized Loss	27	157
Held-to-maturity, Total, Fair Value	19,614	25,024
Held-to-maturity, Total, Gross Unrealized Loss	247	192
GSE mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity, Securities with losses under 12 months, Fair Value	12,552	0
Held-to-maturity, Securities with losses under 12 months, Gross Unrealized Loss	13	0
Held-to-maturity, Securities with losses over 12 months, Fair Value	7,553	8,142
Held-to-maturity, Securities with losses over 12 months, Gross Unrealized Loss	201	164
Held-to-maturity, Total, Fair Value	20,105	8,142
Held-to-maturity, Total, Gross Unrealized Loss	214	164
Collateralized mortgage obligations: residential
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity, Securities with losses under 12 months, Fair Value	0	0
Held-to-maturity, Securities with losses under 12 months, Gross Unrealized Loss	0	0
Held-to-maturity, Securities with losses over 12 months, Fair Value	11,408	12,230
Held-to-maturity, Securities with losses over 12 months, Gross Unrealized Loss	370	479
Held-to-maturity, Total, Fair Value	11,408	12,230
Held-to-maturity, Total, Gross Unrealized Loss	370	479
Collateralized mortgage obligations: commercial
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity, Securities with losses under 12 months, Fair Value	1,402	7,599
Held-to-maturity, Securities with losses under 12 months, Gross Unrealized Loss	1	173
Held-to-maturity, Securities with losses over 12 months, Fair Value	0	0
Held-to-maturity, Securities with losses over 12 months, Gross Unrealized Loss	0	0
Held-to-maturity, Total, Fair Value	1,402	7,599
Held-to-maturity, Total, Gross Unrealized Loss	$ 1	$ 173