Parent Corporation Only Financial Statements (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Assets:
Cash on deposit with subsidiary bank	$ 4,684,000	$ 5,545,000
Interest-bearing deposits at other banks	59,740,000	66,608,000
Other assets	11,925,000	10,065,000
Total assets	601,387,000	614,224,000
Liabilities and Shareholders' Equity
Company-obligated mandatorily redeemable capital securities	4,124,000	4,124,000
Other liabilities	6,181,000	6,960,000
Total liabilities	553,639,000	566,653,000
Shareholders' Equity
Common stock	11,467,000	11,384,000
Retained earnings, which are substantially distributed earnings of subsidiaries	37,993,000	37,504,000
Accumulated other comprehensive income (loss)	(1,712,000)	(1,317,000)
Total shareholders' equity	47,748,000	47,571,000	44,105,000	42,638,000
Total liabilities and shareholders' equity	601,387,000	614,224,000
Income
Interest Income	23,504,000	25,711,000	26,849,000
Total interest and dividend income	24,954,000	27,149,000	28,330,000
Expenses [Abstract]
Interest expense	4,029,000	5,075,000	6,124,000
Miscellaneous	2,810,000	2,671,000	2,913,000
Total expense	19,070,000	20,863,000	20,196,000
Income before income tax benefits and equity in undistributed net income of subsidiaries	2,413,000	5,552,000	4,760,000
Income tax benefit	360,000	1,435,000	1,093,000
Net Income	2,053,000	4,117,000	3,667,000
Cash Flows from Operating Activities
Net Income	2,053,000	4,117,000	3,667,000
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred tax benefit	(53,000)	(119,000)	(854,000)
Tax benefit of nonqualified options exercised	0	(33,000)	(55,000)
Amortization of unearned compensation	140,000	136,000	247,000
(Increase) decrease in other assets	(1,948,000)	492,000	(47,000)
Increase in other liabilities	(1,461,000)	1,754,000	(314,000)
Net cash provided by operating activities	6,040,000	10,678,000	7,148,000
Cash Flows from Financing Activities
Cash dividends paid	(1,774,000)	(1,761,000)	(2,615,000)
Issuance of common stock	153,000	226,000	309,000
Net cash provided by (used in) financing activities	(13,856,000)	8,979,000	26,763,000
Increase (decrease) in cash and cash equivalents	(7,726,000)	24,979,000	20,974,000
Beginning	72,161,000	47,182,000	26,208,000
Ending	64,435,000	72,161,000	47,182,000
Parent Company [Member]
Assets:
Cash on deposit with subsidiary bank	286,000	329,000
Interest-bearing deposits at other banks	1,900,000	1,450,000
Investment in subsidiaries, at cost, plus equity in undistributed net income	50,002,000	50,118,000
Other assets	356,000	347,000
Total assets	52,544,000	52,244,000
Liabilities and Shareholders' Equity
Company-obligated mandatorily redeemable capital securities	4,124,000	4,124,000
Other liabilities	672,000	549,000
Total liabilities	4,796,000	4,673,000
Shareholders' Equity
Common stock	11,467,000	11,384,000
Retained earnings, which are substantially distributed earnings of subsidiaries	37,993,000	37,504,000
Accumulated other comprehensive income (loss)	(1,712,000)	(1,317,000)
Total shareholders' equity	47,748,000	47,571,000
Total liabilities and shareholders' equity	52,544,000	52,244,000
Income
Interest Income	18,000	10,000	0
(Loss) on impairment of securities	0	0	0
Dividends from subsidiaries	2,274,000	2,761,000	3,315,000
Total interest and dividend income	2,292,000	2,771,000	3,315,000
Expenses [Abstract]
Interest expense	200,000	199,000	117,000
Legal and professional fees	163,000	143,000	251,000
Directors' fees	160,000	257,000	302,000
Miscellaneous	158,000	34,000	104,000
Total expense	681,000	633,000	774,000
Income before income tax benefits and equity in undistributed net income of subsidiaries	1,611,000	2,138,000	2,541,000
Income tax benefit	(225,000)	(212,000)	(206,000)
Income before equity in undistributed net income of subsidiaries	1,836,000	2,350,000	2,747,000
Equity in undistributed earnings	217,000	1,767,000	920,000
Net Income	2,053,000	4,117,000	3,667,000
Cash Flows from Operating Activities
Net Income	2,053,000	4,117,000	3,667,000
Adjustments to reconcile net income to net cash provided by operating activities:
Undistributed earnings of subsidiaries	(217,000)	(1,767,000)	(920,000)
Deferred tax benefit	0	0	131,000
Tax benefit of nonqualified options exercised	0	(33,000)	(55,000)
Amortization of unearned compensation	140,000	136,000	247,000
(Increase) decrease in other assets	23,000	12,000	(28,000)
Increase in other liabilities	29,000	(36,000)	28,000
Net cash provided by operating activities	2,028,000	2,429,000	3,070,000
Cash Flows from Financing Activities
Cash dividends paid	(1,774,000)	(1,761,000)	(2,615,000)
Issuance of common stock	153,000	226,000	309,000
Net cash provided by (used in) financing activities	(1,621,000)	(1,535,000)	(2,306,000)
Increase (decrease) in cash and cash equivalents	407,000	894,000	764,000
Beginning	1,779,000	885,000	121,000
Ending	$ 2,186,000	$ 1,779,000	$ 885,000