Stock-Based Compensation (Details 1) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Summary of stock option activity
Outstanding at beginning of year, Shares	214,903	262,042	293,462
Stock option grants, number of shares	0	0	0
Exercised, Shares	(50,930)	(8,800)	0
Forfeited or expired, Shares	(11,077)	(38,339)	(31,420)
Outstanding at end of year, Shares	152,896	214,903	262,042
Options exercisable at year-end, Shares	152,896	212,643	250,222
Summary of stock option activity - weighted average
Weighted Average Exercise Price, Outstanding at beginning of year	$ 22.40	$ 21.18	$ 20.43
Weighted Average Exercise Price, Granted
Weighted Average Exercise Price, Exercised	$ 10.83	$ 6.21
Weighted Average Exercise Price, Forfeited or expired	$ 23.77	$ 17.80	$ 14.15
Weighted Average Exercise Price, Outstanding at end of year	$ 26.15	$ 22.40	$ 21.18
Weighted Average Exercise Price, Options exercisable at year-end	$ 26.15	$ 22.57	$ 21.86