Investment Securities, Amortized Cost, Fair Values, and Unrealized Gains and Losses of Securities (Details) - USD ($) $ in Thousands		Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Amortized cost, fair values, and unrealized gains and losses of securities available-for-sale [Abstract]
Amortized cost		$ 336,259	$ 368,109	$ 359,187
Gross unrealized gains		5,520	2,842	6,194
Gross unrealized losses		8	1,814	197
Fair/Book value		341,771	369,137	365,184
Book values, estimated fair values and unrealized gains and losses of investments classified as held-to-maturity [Abstract]
Book value		61,535	61,396	63,463
Gross unrealized gains		1,357	993	766
Gross unrealized losses		0	1	11
Fair value		62,892	62,388	64,218
Government Agency & Government Sponsored Entities [Member]
Amortized cost, fair values, and unrealized gains and losses of securities available-for-sale [Abstract]
Amortized cost		63,157	33,536	68,064
Gross unrealized gains		190	134	69
Gross unrealized losses		1	419	1
Fair/Book value		63,346	33,251	68,132
US Treasury Notes [Member]
Amortized cost, fair values, and unrealized gains and losses of securities available-for-sale [Abstract]
Amortized cost		65,571	73,048	19,818
Gross unrealized gains		217	0	148
Gross unrealized losses		0	164	0
Fair/Book value		65,788	72,884	19,966
Mortgage Backed Securities [Member]
Amortized cost, fair values, and unrealized gains and losses of securities available-for-sale [Abstract]
Amortized cost	[1]	207,021	261,016	270,820
Gross unrealized gains	[1]	5,113	2,708	5,977
Gross unrealized losses	[1]	7	1,231	196
Fair/Book value	[1]	212,127	262,493	276,601
Other [Member]
Amortized cost, fair values, and unrealized gains and losses of securities available-for-sale [Abstract]
Amortized cost		510	509	485
Gross unrealized gains		0	0	0
Gross unrealized losses		0	0	0
Fair/Book value		510	509	485
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		61,535	61,396	61,324
Gross unrealized gains		1,357	993	766
Gross unrealized losses		0	1	11
Fair value		$ 62,892	$ 62,388	62,079
Other [Member]
Book values, estimated fair values and unrealized gains and losses of investments classified as held-to-maturity [Abstract]
Book value				2,139
Gross unrealized gains				0
Gross unrealized losses				0
Fair value				$ 2,139

[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.