Condensed Financial Statements of Parent Company (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Assets
Cash and cash equivalents	$ 42,317	$ 24,855
Securities held-to-maturity	570	1,515
Other assets	7,859	10,008
Total assets	907,499	849,504
Liabilities & Stockholders' Equity
Common stock	24,795	24,795
Additional paid-in capital	16,392	16,310
Retained earnings	48,305	45,109
Accumulated other comprehensive loss	(192)	(349)	(2,569)
Total liabilities and stockholders' equity	907,499	849,504
Income:
Other income	11,745	9,194
Total operating income	47,539	48,447
Expenses:
Salary and benefits	20,340	19,139
Legal expenses	725	696
Service fees	574	612
Other operating expense	2,474	2,439
Total expenses	34,183	33,679
Income before income taxes and equity in undistributed net income of subsidiaries	5,182	4,353
Income tax benefit	(995)	(1,063)
Net income	4,187	3,290
Cash flows from operating activities:
Net income	4,187	3,290
Adjustments to reconcile net income to net cash provided by operating activities:
Stock compensation expense	82	110
Increase in other assets	1,989	(1,756)
Decrease in other liabilities	410	50
Net cash provided by operating activities	9,775	9,392
Cash flows from investing activities:
Cash flows from investing activities: maturity of investment securities	70,443	132,670
Cash flows from financing activities:
Exercise of stock options	0	284
Cash dividends paid on common stock	(991)	(991)
Net cash used in financing activities	52,691	(43,008)
Net increase (decrease) in cash and cash equivalents	17,462	(3,576)
Cash and cash equivalents at beginning of period	24,855	28,431
Cash and cash equivalents at end of period	42,317	24,855
Parent Company [Member]
Assets
Cash and cash equivalents	220	85
Securities held-to-maturity	0	145
Investment in common stock of subsidiaries	88,815	85,498
Other assets	265	261
Total assets	89,300	85,989
Liabilities & Stockholders' Equity
Note payable - subsidiary	0	124
Common stock	24,795	24,795
Additional paid-in capital	16,392	16,310
Retained earnings	48,305	45,109
Accumulated other comprehensive loss	(192)	(349)
Total liabilities and stockholders' equity	89,300	85,989
Income:
Dividends from subsidiary	1,100	800
Interest on investments	8	16
Other income	660	300
Total operating income	1,768	1,116
Expenses:
Salary and benefits	500	521
Legal expenses	66	56
Service fees	147	160
Other operating expense	33	37
Total expenses	746	774
Income before income taxes and equity in undistributed net income of subsidiaries	1,022	342
Income tax benefit	6	131
Net income before equity in undistributed net income (loss) of subsidiaries	1,028	473
Equity in undistributed net income (loss) of subsidiaries	3,159	2,817
Net income	4,187	3,290
Cash flows from operating activities:
Net income	4,187	3,290
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in undistributed net income of subsidiaries	(3,159)	(2,817)
Stock compensation expense	82	110
Increase in other assets	(4)	(10)
Decrease in other liabilities	(1)	0
Net cash provided by operating activities	1,105	573
Cash flows from investing activities:
Cash flows from investing activities: maturity of investment securities	145	137
Cash flows from financing activities:
Repayment of advances from subsidiaries	(124)	(120)
Exercise of stock options	0	284
Cash dividends paid on common stock	(991)	(991)
Net cash used in financing activities	(1,115)	(827)
Net increase (decrease) in cash and cash equivalents	135	(117)
Cash and cash equivalents at beginning of period	85	202
Cash and cash equivalents at end of period	$ 220	$ 85