Parent Company Only Financial Statements Condensed statements of income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Financial Statements, Captions [Line Items]
Income before income taxes	$ 5,759	$ 6,262	$ 5,885	$ 5,662	$ 5,626	$ 5,851	$ 5,557	$ 5,401	$ 23,568	$ 22,435	$ 17,901
Income tax benefit	(2,140)	(2,352)	(2,220)	(2,134)	(2,117)	(2,204)	(2,078)	(2,011)	(8,846)	(8,410)	(6,529)
Net income	3,619	3,910	3,665	3,528	3,509	3,647	3,479	3,390	14,722	14,025	11,372
Comprehensive income									1,798	15,421	16,586
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Dividends from subsidiaries									1,438	1,438	938
Other income									64	64	40
Total income									1,502	1,502	978
Operating expenses									2,233	2,519	2,414
Income before income taxes									(731)	(1,017)	(1,436)
Income tax benefit									876	990	1,005
Income (loss) before equity in undistributed earnings of subsidiaries									145	(27)	(431)
Equity in undistributed earnings of subsidiaries									14,577	14,052	11,803
Net income									14,722	14,025	11,372
Comprehensive income									$ 1,798	$ 15,421	$ 16,586