Parent Corporation Only Financial Statements (Schedule of Condensed Income Statement) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Condensed Financial Statements, Captions [Line Items]
Dividend Income, Operating									$ 567	$ 629	$ 706
Available-for-sale Securities, Gross Realized Gain (Loss)									893	411	635
Net income	4,469	4,454	4,353	4,231	3,622	3,702	3,584	3,018	17,507	13,926	7,004
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Dividend Income, Operating									2,079	785	500
Other Income									15	7	8
Available-for-sale Securities, Gross Realized Gain (Loss)									26		(97)
Management Fees Revenue									409	294	290
Operating Income (Loss)									2,529	1,086	701
Operating Expenses									(731)	(615)	(635)
Income Loss Before Undistributed Income Of Subsidiaries									1,798	471	66
Equity In Undistributed Income Of Subsidiaries									15,709	13,455	6,938
Net income									$ 17,507	$ 13,926	$ 7,004