Earnings Per Share (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Shares [Abstract]
Basic earnings per share (in shares)	3,691,517	3,666,206	3,627,016
Effect of dilutive securities, stock-based awards (in shares)	15,577	17,955	16,093
Diluted earnings per share (in shares)	3,707,094	3,684,161	3,643,109
Per share amount [Abstract]
Basic earnings per share (in dollars per share)	$ 0.56	$ 1.12	$ 1.01
Diluted earnings per share (in dollars per share)	$ 0.55	$ 1.12	$ 1.01