Loans Impaired Loans (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Recorded Investment [Abstract]
With No Related Allowance	$ 3,866	$ 4,395
With a Related Allowance	1,387
Unpaid Principal Balance [Abstract]
With No Related Allowance	4,033	4,395
With a Related Allowance	1,387
Average Recorded Balance [Abstract]
With No Related Allowance	4,132	3,640	2,837
With a Related Allowance	694
Interest Income Recognized [Abstract]
With No Related Allowance	91	74	161
With a Related Allowance	0
Cash Basis Income [Abstract]
With No Related Allowance	64	42	57
With a Related Allowance	0
Commercial [Member]
Recorded Investment [Abstract]
With No Related Allowance	45	66
With a Related Allowance	1,387
Unpaid Principal Balance [Abstract]
With No Related Allowance	45	66
With a Related Allowance	1,387
Average Recorded Balance [Abstract]
With No Related Allowance	56	40	13
With a Related Allowance	694
Interest Income Recognized [Abstract]
With No Related Allowance	6	6	4
With a Related Allowance	0
Cash Basis Income [Abstract]
With No Related Allowance	0	0	0
With a Related Allowance	0
Commercial Construction [Member]
Recorded Investment [Abstract]
With No Related Allowance	0	0
With a Related Allowance	0
Unpaid Principal Balance [Abstract]
With No Related Allowance	0	0
With a Related Allowance	0
Average Recorded Balance [Abstract]
With No Related Allowance	0	0	0
With a Related Allowance	0
Interest Income Recognized [Abstract]
With No Related Allowance	0	0	0
With a Related Allowance	0
Cash Basis Income [Abstract]
With No Related Allowance	0	0	0
With a Related Allowance	0
Commercial Real Estate [Member]
Recorded Investment [Abstract]
With No Related Allowance	2,528	1,953
With a Related Allowance	0
Unpaid Principal Balance [Abstract]
With No Related Allowance	2,695	1,953
With a Related Allowance	0
Average Recorded Balance [Abstract]
With No Related Allowance	2,241	1,993	1,983
With a Related Allowance	0
Interest Income Recognized [Abstract]
With No Related Allowance	64	42	123
With a Related Allowance	0
Cash Basis Income [Abstract]
With No Related Allowance	64	42	57
With a Related Allowance	0
Other Consumer [Member]
Recorded Investment [Abstract]
With No Related Allowance	0	0
With a Related Allowance	0
Unpaid Principal Balance [Abstract]
With No Related Allowance	0	0
With a Related Allowance	0
Average Recorded Balance [Abstract]
With No Related Allowance	0	5	11
With a Related Allowance	0
Interest Income Recognized [Abstract]
With No Related Allowance	0	0	1
With a Related Allowance	0
Cash Basis Income [Abstract]
With No Related Allowance	0	0	0
With a Related Allowance	0
Automobile [Member]
Recorded Investment [Abstract]
With No Related Allowance	203	268
With a Related Allowance	0
Unpaid Principal Balance [Abstract]
With No Related Allowance	203	268
With a Related Allowance	0
Average Recorded Balance [Abstract]
With No Related Allowance	236	274	280
With a Related Allowance	0
Interest Income Recognized [Abstract]
With No Related Allowance	12	19	16
With a Related Allowance	0
Cash Basis Income [Abstract]
With No Related Allowance	0	0	0
With a Related Allowance	0
Residential [Member]
Recorded Investment [Abstract]
With No Related Allowance	1,090	2,108
With a Related Allowance	0
Unpaid Principal Balance [Abstract]
With No Related Allowance	1,090	2,108
With a Related Allowance	0
Average Recorded Balance [Abstract]
With No Related Allowance	1,599	1,328	550
With a Related Allowance	0
Interest Income Recognized [Abstract]
With No Related Allowance	9	7	17
With a Related Allowance	0
Cash Basis Income [Abstract]
With No Related Allowance	0	0	0
With a Related Allowance	$ 0