Investment Securities Available for Sale (Details) $ in Thousands	Sep. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Securities, at Amortized Cost	$ 315,329	$ 347,615	$ 334,291
Available-for-Sale	315,459	346,996	339,190
Gross Unrealized Gains	1,497	1,576	5,103
Gross Unrealized Losses	1,367	2,195	204
Available-For-Sale Securities, Pledged as Collateral	206,637	262,852	277,832
Maturities of Debt Securities, at Amortized Cost:
Within One Year	14,217
From 1 - 5 Years	262,993
From 5 - 10 Years	35,479
Over 10 Years	1,520
Maturities of Debt Securities, at Fair Value:
Within One Year	14,266
From 1 - 5 Years	263,090
From 5 - 10 Years	35,309
Over 10 Years	1,320
Securities in a Continuous Loss Position, at Fair Value:
Less than 12 Months	175,154	210,095	10,259
12 Months or Longer	1,800	10,186	1,800
Total	$ 176,954	$ 220,281	$ 12,059
Number of Securities in a Continuous Loss Position	57	147	6
Unrealized Losses on Securities in a Continuous Loss Position:
Less than 12 Months	$ 1,166	$ 1,987	$ 4
12 Months or Longer	201	208	200
Total	1,367	2,195	204
U.S. Agency Obligations
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Securities, at Amortized Cost	146,976	147,110	152,511
Available-for-Sale	146,978	147,377	153,926
Gross Unrealized Gains	152	304	1,415
Gross Unrealized Losses	150	37	0
Maturities of Debt Securities, at Amortized Cost:
Within One Year	0
From 1 - 5 Years	146,976
From 5 - 10 Years	0
Over 10 Years	0
Maturities of Debt Securities, at Fair Value:
Within One Year	0
From 1 - 5 Years	146,978
From 5 - 10 Years	0
Over 10 Years	0
Securities in a Continuous Loss Position, at Fair Value:
Less than 12 Months	89,563	70,605	0
12 Months or Longer	0	0	0
Total	$ 89,563	$ 70,605	$ 0
Number of Securities in a Continuous Loss Position	23	19	0
Unrealized Losses on Securities in a Continuous Loss Position:
Less than 12 Months	$ 150	$ 37	$ 0
12 Months or Longer	0	0	0
Total	150	37	0
State and Municipal Obligations
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Securities, at Amortized Cost	11,875	27,684	31,562
Available-for-Sale	11,902	27,690	31,628
Gross Unrealized Gains	27	24	69
Gross Unrealized Losses	0	18	3
Maturities of Debt Securities, at Amortized Cost:
Within One Year	9,068
From 1 - 5 Years	1,890
From 5 - 10 Years	397
Over 10 Years	520
Maturities of Debt Securities, at Fair Value:
Within One Year	9,076
From 1 - 5 Years	1,910
From 5 - 10 Years	396
Over 10 Years	520
Securities in a Continuous Loss Position, at Fair Value:
Less than 12 Months	0	12,165	9,237
12 Months or Longer	0	7,377	0
Total	$ 0	$ 19,542	$ 9,237
Number of Securities in a Continuous Loss Position	0	84	1
Unrealized Losses on Securities in a Continuous Loss Position:
Less than 12 Months	$ 0	$ 13	$ 3
12 Months or Longer	0	5	0
Total	0	18	3
Mortgage-Backed Securities - Residential
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Securities, at Amortized Cost	152,858	168,189	144,598
Available-for-Sale	152,806	167,239	148,087
Gross Unrealized Gains	964	986	3,489
Gross Unrealized Losses	1,016	1,936	0
Maturities of Debt Securities, at Amortized Cost:
Within One Year	3,649
From 1 - 5 Years	114,127
From 5 - 10 Years	35,082
Over 10 Years	0
Maturities of Debt Securities, at Fair Value:
Within One Year	3,691
From 1 - 5 Years	114,202
From 5 - 10 Years	34,913
Over 10 Years	0
Securities in a Continuous Loss Position, at Fair Value:
Less than 12 Months	85,091	126,825	0
12 Months or Longer	0	0	0
Total	$ 85,091	$ 126,825	$ 0
Number of Securities in a Continuous Loss Position	31	40	2
Unrealized Losses on Securities in a Continuous Loss Position:
Less than 12 Months	$ 1,016	$ 1,936	$ 0
12 Months or Longer	0	0	0
Total	1,016	1,936	0
Corporate and Other Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Securities, at Amortized Cost	2,500	3,512	4,500
Available-for-Sale	2,299	3,308	4,299
Gross Unrealized Gains	0	0	0
Gross Unrealized Losses	201	204	201
Maturities of Debt Securities, at Amortized Cost:
Within One Year	1,500
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	1,499
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	500	500	1,022
12 Months or Longer	1,800	2,809	1,800
Total	$ 2,300	$ 3,309	$ 2,822
Number of Securities in a Continuous Loss Position	3	4	3
Unrealized Losses on Securities in a Continuous Loss Position:
Less than 12 Months	$ 0	$ 1	$ 1
12 Months or Longer	201	203	200
Total	201	204	201
Mutual Funds and Equity Securities
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Securities, at Amortized Cost	1,120	1,120	1,120
Available-for-Sale	1,474	1,382	1,250
Gross Unrealized Gains	354	262	130
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
Fair Value, Measurements, Recurring
Schedule of Available-for-sale Securities [Line Items]
Available-for-Sale	315,459	346,996	339,190
Fair Value, Measurements, Recurring | U.S. Agency Obligations
Schedule of Available-for-sale Securities [Line Items]
Available-for-Sale	146,978	147,377	153,926
Fair Value, Measurements, Recurring | State and Municipal Obligations
Schedule of Available-for-sale Securities [Line Items]
Available-for-Sale	11,902	27,690	31,628
Fair Value, Measurements, Recurring | Corporate and Other Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-Sale	2,299	3,308	4,299
Fair Value, Measurements, Recurring | Mutual Funds and Equity Securities
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Securities, at Amortized Cost	1,500
Available-for-Sale	1,474	1,382	1,250
US Treasury Securities | U.S. Agency Obligations
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Securities, at Amortized Cost	64,711	54,701
Available-for-Sale	64,730	54,706
Agency Securities | U.S. Agency Obligations
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Securities, at Amortized Cost	82,265	92,409	152,511
Available-for-Sale	82,248	92,671	153,926
Agency Securities | Mortgage-Backed Securities - Residential
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Securities, at Amortized Cost	503	3,694	10,849
Available-for-Sale	505	3,724	11,003
US Government-sponsored Enterprises Debt Securities | Mortgage-Backed Securities - Residential
Schedule of Available-for-sale Securities [Line Items]
Available-for-Sale	152,301	163,515	137,084
US Government-sponsored Enterprises Debt Securities | Mortgage-Backed Securities - Residential | US Government-sponsored Enterprises Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Available-For-Sale Securities, at Amortized Cost	$ 152,355	$ 164,495	$ 133,749