Investment Securities - Investments' Gross Unrealized Losses and Fair Value Aggregated by Investment Category and Length of Time in Continuous Unrealized Loss Position (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Fair Value
Less than 12 Months	$ 43,184	$ 3,442
12 Months or Longer	2,125	15,297
Total	45,309	18,739
Gross Unrealized Losses
Less than 12 Months	505	20
12 Months or Longer	65	230
Total	570	250
Fair Value
Less than 12 Months	34,463	14,910
12 Months or Longer	15,207	38,741
Total	49,670	53,651
Gross Unrealized Losses
Less than 12 Months	184	178
12 Months or Longer	195	430
Total	379	608
Available-for-sale Securities and Held-to-maturity Securities [Abstract]
Less than 12 Months, Fair Value	77,647	18,352
12 Months or Longer, Fair Value	17,332	54,038
Total, Fair Value	94,979	72,390
Less than 12 Months, Gross Unrealized Losses	689	198
12 Months or Longer, Gross Unrealized Losses	260	660
Total, Gross Unrealized Losses	949	858
State and municipal
Fair Value
Less than 12 Months	$ 36,702	1,256
12 Months or Longer		9,850
Total	$ 36,702	11,106
Gross Unrealized Losses
Less than 12 Months	$ 497	7
12 Months or Longer		116
Total	$ 497	123
U.S. Government-sponsored mortgage-backed securities
Fair Value
Less than 12 Months	6,482	2,186
12 Months or Longer	2,125	5,447
Total	8,607	7,633
Gross Unrealized Losses
Less than 12 Months	8	13
12 Months or Longer	65	114
Total	73	127
State and municipal
Fair Value
Less than 12 Months	13,711	5,119
12 Months or Longer	1,716	250
Total	15,427	5,369
Gross Unrealized Losses
Less than 12 Months	144	$ 96
12 Months or Longer	22
Total	166	$ 96
U.S. Government-sponsored mortgage-backed securities
Fair Value
Less than 12 Months	20,752	9,791
12 Months or Longer	13,491	38,491
Total	34,243	48,282
Gross Unrealized Losses
Less than 12 Months	40	82
12 Months or Longer	173	430
Total	$ 213	$ 512