Earnings Per Share (Tables)

12 Months Ended

Dec. 31, 2016

Earnings Per Share [Abstract]

Reconciliation Between Basic and Diluted Earnings Per Share

A reconciliation between basic and diluted earnings per share is as follows (in thousands, except per share data):

	Year Ended December 31,
	2016		2015		2014
Net income for basic and diluted earnings per share	$	1,283,388	$	665,783	$	764,146
Weighted-average common shares outstanding	215,393		219,537		221,658
Dilutive effect of stock options, performance share awards and restricted stock awards	923		1,152		1,386
Diluted weighted-average shares outstanding	216,316		220,689		223,044
Basic earnings per share:
Net income	$	5.96	$	3.03	$	3.45
Diluted earnings per share:
Net income	$	5.93	$	3.02	$	3.43