5. Securities (Summary Of Amortized Cost, Unrealized Gains, Unrealized Losses And Estimated Fair Values) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Available for sale securities, Amortized Cost	$ 290,603	$ 283,033	$ 273,684
Available for sale securities, Unrealized Gains	4,809	9,906	8,855
Available for sale securities, Unrealized Losses	4,154	947	1,000
Available for sale securities, Estimated Fair Value	291,258	291,992	281,539
U S Government Corporations And Agencies Securities [Member]
Available for sale securities, Amortized Cost	27,740	25,857	28,128
Available for sale securities, Unrealized Gains	757	1,009	892
Available for sale securities, Unrealized Losses	67	4	0
Available for sale securities, Estimated Fair Value	28,430	26,862	29,020
Government Sponsored Agencies [Member]
Available for sale securities, Amortized Cost	149,569	150,233	133,812
Available for sale securities, Unrealized Gains	2,444	3,741	3,250
Available for sale securities, Unrealized Losses	1,226	453	492
Available for sale securities, Estimated Fair Value	150,787	153,521	136,570
Nongovernment Sponsored Agencies [Member]
Available for sale securities, Amortized Cost	13,134	21,199	15,380
Available for sale securities, Unrealized Gains	315	712	509
Available for sale securities, Unrealized Losses	9	290	144
Available for sale securities, Estimated Fair Value	13,440	21,621	15,745
U S States And Political Subdivisions General Obligations [Member]
Available for sale securities, Amortized Cost	9,064	10,176	8,847
Available for sale securities, Unrealized Gains	0	57	58
Available for sale securities, Unrealized Losses	383	56	57
Available for sale securities, Estimated Fair Value	8,681	10,177	8,848
State and Policital Subdivisions Water and Sewer Revenues [Member]
Available for sale securities, Amortized Cost	3,234		1,920
Available for sale securities, Unrealized Gains	1		0
Available for sale securities, Unrealized Losses	91		32
Available for sale securities, Estimated Fair Value	3,144		1,888
State and Policital Subdivisions Other Revenues [Member]
Available for sale securities, Amortized Cost	3,298		1,420
Available for sale securities, Unrealized Gains	0		13
Available for sale securities, Unrealized Losses	112		0
Available for sale securities, Estimated Fair Value	3,186		1,433
Corporate Debt Securities [Member]
Available for sale securities, Amortized Cost	3,970	1,955	1,959
Available for sale securities, Unrealized Gains	25	29	29
Available for sale securities, Unrealized Losses	45	74	38
Available for sale securities, Estimated Fair Value	3,950	1,910	1,950
Taxable Debt Securities [Member]
Available for sale securities, Amortized Cost	210,009	209,420	191,466
Available for sale securities, Unrealized Gains	3,542	5,548	4,751
Available for sale securities, Unrealized Losses	1,933	877	763
Available for sale securities, Estimated Fair Value	211,618	214,091	195,454
State and Political Subdivisions General Obligations [Member]
Available for sale securities, Amortized Cost	49,569		54,948
Available for sale securities, Unrealized Gains	1,048		3,259
Available for sale securities, Unrealized Losses	1,112		145
Available for sale securities, Estimated Fair Value	49,505		58,062
State and Political Subdivisions Water and Sewer Revenues [Member]
Available for sale securities, Amortized Cost	10,132		5,773
Available for sale securities, Unrealized Gains	89		171
Available for sale securities, Unrealized Losses	290		47
Available for sale securities, Estimated Fair Value	9,931		5,897
State and Political Subdivisions Lease Revenues [Member]
Available for sale securities, Amortized Cost	8,869		6,910
Available for sale securities, Unrealized Gains	1		159
Available for sale securities, Unrealized Losses	441		13
Available for sale securities, Estimated Fair Value	8,429		7,056
State and Political Subdivisions Lottery/casino Revenues [Member]
Available for sale securities, Amortized Cost	4,457		4,500
Available for sale securities, Unrealized Gains	68		305
Available for sale securities, Unrealized Losses	166		9
Available for sale securities, Estimated Fair Value	4,359		4,796
State and Political Subdivisions Other Revenues [Member]
Available for sale securities, Amortized Cost	7,490		7,272
Available for sale securities, Unrealized Gains	61		210
Available for sale securities, Unrealized Losses	212		23
Available for sale securities, Estimated Fair Value	7,339		7,459
Tax Exempt Debt Securities [Member]
Available for sale securities, Amortized Cost	80,517	73,536	82,141
Available for sale securities, Unrealized Gains	1,267	4,358	4,104
Available for sale securities, Unrealized Losses	2,221	70	237
Available for sale securities, Estimated Fair Value	79,563	77,824	86,008
Equity Securities [Member]
Available for sale securities, Amortized Cost	77	77	77
Available for sale securities, Unrealized Gains	0	0	0
Available for sale securities, Unrealized Losses	0	0	0
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	0	2,858	2,738
Available for sale securities, Unrealized Gains	0	0	0
Available for sale securities, Unrealized Losses	0	0	0
Available for sale securities, Estimated Fair Value	$ 0	$ 2,858	$ 2,738