Basis of Presentation (Details) (USD $)	9 Months Ended	12 Months Ended
	Sep. 30, 2012	Dec. 31, 2011
Summary of stock option activity
Options outstanding, number of options, beginning	13,786	18,872
Options forfeited, Number of Options	(2,670)	(5,086)
Options outstanding and exercisable, Number of options, ending	11,116	13,786
Options outstanding, weighted average price, beginning	$ 29.60	$ 29.32
Options forfeited, weighted average price	$ 23.23	$ 28.57
Options outstanding and exercisable, weighted average price, ending	$ 31.13	$ 29.60
Options outstanding and exercisable, weighted average remaining contractual life, ending	1 year 3 months 22 days	1 year 8 months 23 days
Options outstanding and exercisable, aggregate intrinsic value, ending	$ 0	$ 0