Stock Based Compensation (Details) (USD $) In Thousands, except Share data, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011
Summary the stock option transactions
Number of Options Outstanding at January 1, 2012	227,747
Weighted Average Exercise Price Outstanding, at January 1, 2012	$ 49.86
Weighted Average Remaining Contractual Term (Years)		3 years 7 months 6 days
Aggregate Intrinsic Value Outstanding, at January 1, 2012	$ 109,299
Number of Options Granted
Weighted Average Exercise Price, Granted
Number of Options Exercised
Weighted Average Exercise Price, Exercised
Number of Options Expired	(24,566)
Number of Options Forfeited
Weighted Average Exercise Price, Expired	$ 82.85
Weighted Average Exercise Price, Forfeited
Number of Options Outstanding and exercisable, at June 30, 2012	203,181
Weighted Average Exercise Price, Outstanding and exercisable at June 30, 2012	$ 45.88
Weighted Average Remaining Contractual Term (Years), Outstanding and exercisable	3 years 6 months
Aggregate Intrinsic Value of Stock Options, Outstanding and exercisable	$ 109,299