Loans and Allowance for Loan Losses (Details 6) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Average recorded investment and interest income recognized on impaired loans
Average recorded investment	$ 15,341	$ 17,821	$ 16,090	$ 17,778	$ 17,854
Recognized interest income	196	121	316	344	629
Commercial [Member]
Average recorded investment and interest income recognized on impaired loans
Average recorded investment	13,366	15,758	14,098	15,632	15,699
Recognized interest income	155	106	264	312	559
Commercial [Member] | Owner occupied RE [Member]
Average recorded investment and interest income recognized on impaired loans
Average recorded investment	1,191	4,330	1,551	4,577	3,881
Recognized interest income	4	2	7	76	17
Commercial [Member] | Non-owner occupied RE [Member]
Average recorded investment and interest income recognized on impaired loans
Average recorded investment	5,715	5,563	6,198	4,921	5,811
Recognized interest income	78	77	145	179	392
Commercial [Member] | Construction [Member]
Average recorded investment and interest income recognized on impaired loans
Average recorded investment	1,987	2,201	2,018	2,157	2,127
Recognized interest income	16	18	26	41	66
Commercial [Member] | Business [Member]
Average recorded investment and interest income recognized on impaired loans
Average recorded investment	4,473	3,664	4,331	3,977	3,880
Recognized interest income	57	9	86	16	84
Consumer [Member]
Average recorded investment and interest income recognized on impaired loans
Average recorded investment	1,975	2,063	1,992	2,146	2,155
Recognized interest income	41	15	52	32	70
Consumer [Member] | Real estate [Member]
Average recorded investment and interest income recognized on impaired loans
Average recorded investment	1,026	1,307	239	1,436	1,397
Recognized interest income	36	10	43	21	44
Consumer [Member] | Home equity [Member]
Average recorded investment and interest income recognized on impaired loans
Average recorded investment	726	524	1,012	478	518
Recognized interest income	3	2	5	5	12
Consumer [Member] | Construction [Member]
Average recorded investment and interest income recognized on impaired loans
Average recorded investment
Recognized interest income
Consumer [Member] | Other [Member]
Average recorded investment and interest income recognized on impaired loans
Average recorded investment	223	232	741	232	240
Recognized interest income	$ 2	$ 3	$ 4	$ 6	$ 14