Stock Option and Incentive Plan Stock Option and Incentive Plan and Stock Purchase Plan (Tables)

12 Months Ended

Dec. 31, 2012

Stock Option and Incentive Plan and Stock Purchase Plan [Abstract]

Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]

	Shares		Weighted Average Exercise Price
Outstanding at December 31, 2009	963,895		$	34.44
Granted	—		$	—
Exercised	(638,957	)	$	35.35
Canceled	—		$	—
Outstanding at December 31, 2010	324,938		$	32.65
Granted	146,844		$	92.71
Exercised	(316,159	)	$	32.63
Canceled	—		$	—
Outstanding at December 31, 2011	155,623		$	89.35
Granted	186,007		$	107.23
Exercised	(22,823	)	$	72.42
Canceled	(24,280	)	$	100.15
Outstanding at December 31, 2012	294,527		$	101.06

Schedule of Stock Options Outstanding [Table Text Block]

The following table summarizes information about stock options outstanding at December 31, 2012:

Options Outstanding						Options Exercisable
Exercise Prices		Number Outstanding at 12/31/12	Weighted-Average Remaining Contractual Life	Weighted-Average Exercise Price		Number Exercisable at 12/31/12	Weighted-Average Exercise Price
$	92.71	128,989	8.1 Years	$	92.71	53,266	$	92.71
$	107.57	165,538	9.1 Years	$	107.57	38,230	$	107.57