Investment Securities, Amortized Cost, Fair Values, and Unrealized Gains and Losses of Securities (Details) - USD ($) $ in Thousands		Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Amortized cost, fair values, and unrealized gains and losses of securities available-for-sale [Abstract]
Amortized cost		$ 455,367	$ 448,282	$ 352,877
Gross unrealized gains		2,110	1,886	5,981
Gross unrealized losses		1,154	1,905	1
Fair/Book value		456,323	448,263	358,857
Book values, estimated fair values and unrealized gains and losses of investments classified as held-to-maturity [Abstract]
Book value		55,542	58,109	58,905
Gross unrealized gains		749	339	1,549
Gross unrealized losses		0	40	0
Fair value		56,291	58,408	60,454
Government Agency & Government-Sponsored Entities [Member]
Amortized cost, fair values, and unrealized gains and losses of securities available-for-sale [Abstract]
Amortized cost		3,091	3,127	83,129
Gross unrealized gains		78	114	165
Gross unrealized losses		0	0	1
Fair/Book value		3,169	3,241	83,293
US Treasury Notes [Member]
Amortized cost, fair values, and unrealized gains and losses of securities available-for-sale [Abstract]
Amortized cost		144,657	134,755	85,470
Gross unrealized gains		2	5	211
Gross unrealized losses		249	332	0
Fair/Book value		144,410	134,428	85,681
US Govt SBA [Member]
Amortized cost, fair values, and unrealized gains and losses of securities available-for-sale [Abstract]
Amortized cost		31,732	36,532
Gross unrealized gains		45	42
Gross unrealized losses		86	260
Fair/Book value		31,691	36,314
Mortgage Backed Securities [Member]
Amortized cost, fair values, and unrealized gains and losses of securities available-for-sale [Abstract]
Amortized cost	[1]	274,877	272,858	183,268
Gross unrealized gains	[1]	1,985	1,725	5,605
Gross unrealized losses	[1]	819	1,313	0
Fair/Book value	[1]	276,043	273,270	188,873
Other [Member]
Amortized cost, fair values, and unrealized gains and losses of securities available-for-sale [Abstract]
Amortized cost		1,010	1,010	1,010
Gross unrealized gains		0	0	0
Gross unrealized losses		0	0	0
Fair/Book value		1,010	1,010	1,010
Obligations of States and Political Subdivisions [Member]
Book values, estimated fair values and unrealized gains and losses of investments classified as held-to-maturity [Abstract]
Book value		55,542	58,109	58,905
Gross unrealized gains		749	339	1,549
Gross unrealized losses		0	40	0
Fair value		$ 56,291	$ 58,408	$ 60,454

[1] All Mortgage Backed Securities consist of securities collateralized by residential real estate and were issued by an agency or government sponsored entity of the U.S. government.