Earnings Per Share (Tables)

12 Months Ended

Dec. 31, 2016

Earnings Per Share [Abstract]

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

The following table sets forth the computation of basic and diluted earnings per share on net income (in thousands, except per share information):

	2016		2015		2014
Earnings:
Net income (numerator for basic and diluted calculations)	$	701,443	$	502,166	$	684,047
Shares:
Weighted average outstanding shares (denominator for basic calculations)	64,274		66,553		69,248
Equivalent shares from outstanding stock options	715		739		714
Diluted shares (denominator for diluted calculations)	64,989		67,292		69,962
Earnings per share:
Basic	$	10.91	$	7.55	$	9.88
Diluted	10.79		7.46		9.78