5. Securities (Summary Of Amortized Cost, Unrealized Gains, Unrealized Losses And Estimated Fair Values) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Available for sale securities, Amortized Cost	$ 279,511	$ 275,522	$ 289,614
Available for sale securities, Unrealized Gains	4,820	8,644	3,851
Available for sale securities, Unrealized Losses	2,466	1,112	4,685
Available for sale securities, Estimated Fair Value	281,865	283,054	288,780
U S Government Corporations And Agencies Securities [Member]
Available for sale securities, Amortized Cost	27,658	30,782	29,100
Available for sale securities, Unrealized Gains	736	1,035	675
Available for sale securities, Unrealized Losses	78		118
Available for sale securities, Estimated Fair Value	28,316	31,817	29,657
Government Sponsored Agencies [Member]
Available for sale securities, Amortized Cost	142,644	142,534	155,270
Available for sale securities, Unrealized Gains	2,230	3,444	2,019
Available for sale securities, Unrealized Losses	1,060	647	1,573
Available for sale securities, Estimated Fair Value	143,814	145,331	155,716
Nongovernment Sponsored Agencies [Member]
Available for sale securities, Amortized Cost	10,429	13,691	11,519
Available for sale securities, Unrealized Gains	377	483	321
Available for sale securities, Unrealized Losses	19	83	21
Available for sale securities, Estimated Fair Value	10,787	14,091	11,819
U S States And Political Subdivisions General Obligations [Member]
Available for sale securities, Amortized Cost	5,681	13,889	9,317
Available for sale securities, Unrealized Gains	7	122
Available for sale securities, Unrealized Losses	209	93	475
Available for sale securities, Estimated Fair Value	5,479	13,918	8,842
State and Policital Subdivisions Water and Sewer Revenues [Member]
Available for sale securities, Amortized Cost	2,389		3,229
Available for sale securities, Unrealized Gains	8
Available for sale securities, Unrealized Losses	60		114
Available for sale securities, Estimated Fair Value	2,337		3,115
State and Policital Subdivisions Other Revenues [Member]
Available for sale securities, Amortized Cost	3,021		4,051
Available for sale securities, Unrealized Gains			4
Available for sale securities, Unrealized Losses	106		142
Available for sale securities, Estimated Fair Value	2,915		3,913
Corporate Debt Securities [Member]
Available for sale securities, Amortized Cost	3,977	2,962	3,973
Available for sale securities, Unrealized Gains	25	33	24
Available for sale securities, Unrealized Losses	4	18	31
Available for sale securities, Estimated Fair Value	3,998	2,977	3,966
Taxable Debt Securities [Member]
Available for sale securities, Amortized Cost	195,799	203,858	216,459
Available for sale securities, Unrealized Gains	3,383	5,117	3,043
Available for sale securities, Unrealized Losses	1,536	841	2,474
Available for sale securities, Estimated Fair Value	197,646	208,134	217,028
State and Political Subdivisions General Obligations [Member]
Available for sale securities, Amortized Cost	45,761		41,156
Available for sale securities, Unrealized Gains	1,109		675
Available for sale securities, Unrealized Losses	504		1,154
Available for sale securities, Estimated Fair Value	46,366		40,677
State and Political Subdivisions Water and Sewer Revenues [Member]
Available for sale securities, Amortized Cost	14,033		8,996
Available for sale securities, Unrealized Gains	64		15
Available for sale securities, Unrealized Losses	110		306
Available for sale securities, Estimated Fair Value	13,987		8,705
State and Political Subdivisions Lease Revenues [Member]
Available for sale securities, Amortized Cost	9,079		7,956
Available for sale securities, Unrealized Gains	47
Available for sale securities, Unrealized Losses	168		391
Available for sale securities, Estimated Fair Value	8,958		7,565
State and Political Subdivisions Lottery/casino Revenues [Member]
Available for sale securities, Amortized Cost	4,428		4,443
Available for sale securities, Unrealized Gains	102		63
Available for sale securities, Unrealized Losses	79		169
Available for sale securities, Estimated Fair Value	4,415		4,337
State and Political Subdivisions Other Revenues [Member]
Available for sale securities, Amortized Cost	10,334		10,527
Available for sale securities, Unrealized Gains	115		55
Available for sale securities, Unrealized Losses	69		191
Available for sale securities, Estimated Fair Value	10,380		10,391
Tax Exempt Debt Securities [Member]
Available for sale securities, Amortized Cost	83,635	71,587	73,078
Available for sale securities, Unrealized Gains	1,437	3,527	808
Available for sale securities, Unrealized Losses	930	271	2,211
Available for sale securities, Estimated Fair Value	84,142	74,843	71,675
Tax Exempt Debt Securities Us States And Political Subdivisions [Member]
Available for sale securities, Amortized Cost		68,945
Available for sale securities, Unrealized Gains		3,527
Available for sale securities, Unrealized Losses		271
Available for sale securities, Estimated Fair Value		72,201
Equity Securities [Member]
Available for sale securities, Amortized Cost	77	77	77
Available for sale securities, Unrealized Gains
Available for sale securities, Unrealized Losses
Available for sale securities, Estimated Fair Value	77	77	77
Tax Exempt Debt Securities Residential Mortgage Backed Securities [Member]
Available for sale securities, Amortized Cost		2,642
Available for sale securities, Unrealized Gains
Available for sale securities, Unrealized Losses
Available for sale securities, Estimated Fair Value		$ 2,642