Earnings Per Share (Tables)

6 Months Ended

Jun. 30, 2017

Earnings Per Share [Abstract]

Schedule Of Earnings Per Share Basic And Diluted By Common Class [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):

	Three months ended June 30,				Six months ended June 30,
	2017		2016		2017		2016
Earnings:
Net income (numerator for basic and diluted calculations)	$	232,190	$	236,103	$	377,702	$	312,575
Shares:
Weighted average outstanding shares (denominator for basic calculation)	64,449		64,126		64,401		64,348
Equivalent shares from outstanding stock options	1,159		670		1,204		660
Denominator for diluted calculation	65,608		64,796		65,605		65,008
Earnings per share:
Basic	$	3.60	$	3.68	$	5.86	$	4.86
Diluted	$	3.54	$	3.64	$	5.76	$	4.81