Earnings Per Share (Tables)

12 Months Ended

Dec. 31, 2011

Earnings Per Share [Abstract]

Schedule Of Earnings Per Share Basic And Diluted By Common Class [Table Text Block]

			2011			2010			2009
Earnings:
	Net income (numerator for basic and diluted calculations)		$	599,620		$	574,402		$	407,086
Shares:
	Weighted average outstanding shares (denominator for basic calculations)
					73,586			73,157			72,790
Equivalent shares from outstanding stock options and warrants				522			1,537			537
		Diluted shares (denominator for diluted calculations)		74,108			74,694			73,327
Earnings per share:
	Basic		$	8.15		$	7.85		$	5.59
	Diluted		$	8.09		$	7.69		$	5.55