Investment Securities Available for Sale (Details) $ in Thousands	Sep. 30, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)
Available-For-Sale Securities
Available-For-Sale Securities, at Amortized Cost	$ 347,916	$ 301,876	$ 315,329
Available-for-Sale	340,411	300,200	315,459
Gross Unrealized Gains	204	935	1,497
Gross Unrealized Losses	7,709	2,611	1,367
Maturities of Debt Securities, at Amortized Cost:
Within One Year	44,991
From 1 - 5 Years	183,041
From 5 - 10 Years	103,597
Over 10 Years	16,287
Maturities of Debt Securities, at Fair Value:
Within One Year	44,781
From 1 - 5 Years	176,760
From 5 - 10 Years	102,800
Over 10 Years	16,070
Securities in a Continuous Loss Position, at Fair Value:
Less than 12 Months	173,669	99,776	175,154
12 Months or Longer	127,004	121,105	1,800
Total	$ 300,673	$ 220,881	$ 176,954
Number of Securities in a Continuous Loss Position	110	106	57
Unrealized Losses on Securities in a Continuous Loss Position:
Less than 12 Months	$ 3,358	$ 546	$ 1,166
12 Months or Longer	4,351	2,065	201
Total	7,709	2,611	1,367
U.S. Agency Obligations
Available-For-Sale Securities
Available-For-Sale Securities, at Amortized Cost	60,135	60,328	146,976
Available-for-Sale	59,602	59,894	146,978
Gross Unrealized Gains	0	0	152
Gross Unrealized Losses	533	434	150
Maturities of Debt Securities, at Amortized Cost:
Within One Year	42,621
From 1 - 5 Years	17,514
From 5 - 10 Years	0
Over 10 Years	0
Maturities of Debt Securities, at Fair Value:
Within One Year	42,410
From 1 - 5 Years	17,192
From 5 - 10 Years	0
Over 10 Years	0
Securities in a Continuous Loss Position, at Fair Value:
Less than 12 Months	4,831	20,348	89,563
12 Months or Longer	54,771	39,546	0
Total	$ 59,602	$ 59,894	$ 89,563
Number of Securities in a Continuous Loss Position	14	14	23
Unrealized Losses on Securities in a Continuous Loss Position:
Less than 12 Months	$ 193	$ 172	$ 150
12 Months or Longer	340	262	0
Total	533	434	150
State and Municipal Obligations
Available-For-Sale Securities
Available-For-Sale Securities, at Amortized Cost	2,545	10,351	11,875
Available-for-Sale	2,548	10,349	11,902
Gross Unrealized Gains	3	9	27
Gross Unrealized Losses	0	11	0
Maturities of Debt Securities, at Amortized Cost:
Within One Year	1,346
From 1 - 5 Years	719
From 5 - 10 Years	0
Over 10 Years	480
Maturities of Debt Securities, at Fair Value:
Within One Year	1,346
From 1 - 5 Years	722
From 5 - 10 Years	0
Over 10 Years	480
Securities in a Continuous Loss Position, at Fair Value:
Less than 12 Months	1,120	8,498	0
12 Months or Longer	0	0	0
Total	$ 1,120	$ 8,498	$ 0
Number of Securities in a Continuous Loss Position	5	36	0
Unrealized Losses on Securities in a Continuous Loss Position:
Less than 12 Months	$ 0	$ 11	$ 0
12 Months or Longer	0	0	0
Total	0	11	0
Mortgage-Backed Securities - Residential
Available-For-Sale Securities
Available-For-Sale Securities, at Amortized Cost	284,236	229,077	152,858
Available-for-Sale	277,461	227,596	152,806
Gross Unrealized Gains	201	485	964
Gross Unrealized Losses	6,976	1,966	1,016
Maturities of Debt Securities, at Amortized Cost:
Within One Year	1,024
From 1 - 5 Years	164,808
From 5 - 10 Years	103,597
Over 10 Years	14,807
Maturities of Debt Securities, at Fair Value:
Within One Year	1,025
From 1 - 5 Years	158,846
From 5 - 10 Years	102,800
Over 10 Years	14,790
Securities in a Continuous Loss Position, at Fair Value:
Less than 12 Months	167,718	70,930	85,091
12 Months or Longer	71,433	80,759	0
Total	$ 239,151	$ 151,689	$ 85,091
Number of Securities in a Continuous Loss Position	90	55	31
Unrealized Losses on Securities in a Continuous Loss Position:
Less than 12 Months	$ 3,165	$ 363	$ 1,016
12 Months or Longer	3,811	1,603	0
Total	6,976	1,966	1,016
Corporate and Other Debt Securities
Available-For-Sale Securities
Available-For-Sale Securities, at Amortized Cost	1,000	1,000	2,500
Available-for-Sale	800	800	2,299
Gross Unrealized Gains	0	0	0
Gross Unrealized Losses	200	200	201
Maturities of Debt Securities, at Amortized Cost:
Within One Year	0
From 1 - 5 Years	0
From 5 - 10 Years	0
Over 10 Years	1,000
Maturities of Debt Securities, at Fair Value:
Within One Year	0
From 1 - 5 Years	0
From 5 - 10 Years	0
Over 10 Years	800
Securities in a Continuous Loss Position, at Fair Value:
Less than 12 Months	0	0	500
12 Months or Longer	800	800	1,800
Total	$ 800	$ 800	$ 2,300
Number of Securities in a Continuous Loss Position	1	1	3
Unrealized Losses on Securities in a Continuous Loss Position:
Less than 12 Months	$ 0	$ 0	$ 0
12 Months or Longer	200	200	201
Total	200	200	201
Mutual Funds and Equity Securities
Available-For-Sale Securities
Available-For-Sale Securities, at Amortized Cost	0	1,120	1,120
Available-for-Sale	0	1,561	1,474
Gross Unrealized Gains	0	441	354
Gross Unrealized Losses	0	0	0
Securities in a Continuous Loss Position, at Fair Value:
Less than 12 Months	0	0	0
12 Months or Longer	0	0	0
Total	$ 0	$ 0	$ 0
Number of Securities in a Continuous Loss Position	0	0	0
Unrealized Losses on Securities in a Continuous Loss Position:
Less than 12 Months	$ 0	$ 0	$ 0
12 Months or Longer	0	0	0
Total	0	0	0
Collateral Pledged
Available-For-Sale Securities
Available-For-Sale Securities, Pledged as Collateral	219,587	183,052	206,637
US Treasury Securities | U.S. Agency Obligations
Available-For-Sale Securities
Available-For-Sale Securities, at Amortized Cost	0	0	64,711
Available-for-Sale	0	0	64,730
Agency Securities | U.S. Agency Obligations
Available-For-Sale Securities
Available-For-Sale Securities, at Amortized Cost	60,135	60,328	82,265
Available-for-Sale	59,602	59,894	82,248
US Government Agencies Debt Securities | Mortgage-Backed Securities - Residential
Available-For-Sale Securities
Available-For-Sale Securities, at Amortized Cost	74,160	40,832	503
Available-for-Sale	74,098	40,832	505
US Government-sponsored Enterprises Debt Securities | Mortgage-Backed Securities - Residential
Available-For-Sale Securities
Available-For-Sale Securities, at Amortized Cost	210,076	188,245	152,355
Available-for-Sale	$ 203,363	$ 186,764	$ 152,301