Investment Securities, Continuous Unrealized Loss Position (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Available-for-Sale:
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	$ 49,198	$ 203,421
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	316	5,992
Held-to-Maturity:
Less than 12 Months, Fair Value	991	766
Less than 12 Months, Unrealized Losses	1	2
12 Months or More, Fair Value	2,649	21,742
12 Months or More, Unrealized Losses	16	779
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	15,879	19,389
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	49	56
U.S. Treasury notes [Member]
Available-for-Sale:
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	0	2,235
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	43
Held-to-Maturity:
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	0	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
U.S. Agency notes [Member]
Available-for-Sale:
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	21,900	73,351
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	59	2,361
Held-to-Maturity:
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	0	4,988
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	7
U.S. Agency mortgage-backed securities [Member]
Available-for-Sale:
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	21,758	55,217
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	231	1,981
Held-to-Maturity:
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	2,818	137
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	2	0
Non-taxable Municipal securities [Member]
Available-for-Sale:
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	1,492	58,211
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	21	1,373
Held-to-Maturity:
Less than 12 Months, Fair Value	991	366
Less than 12 Months, Unrealized Losses	1	1
12 Months or More, Fair Value	2,649	18,588
12 Months or More, Unrealized Losses	16	634
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	13,061	14,264
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	47	49
Taxable Municipal securities [Member]
Available-for-Sale:
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	4,048	14,407
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	5	234
Held-to-Maturity:
Less than 12 Months, Fair Value	0	400
Less than 12 Months, Unrealized Losses	0	1
12 Months or More, Fair Value	0	3,154
12 Months or More, Unrealized Losses	0	145
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	0	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ 0	$ 0