XML 55 R39.htm IDEA: XBRL DOCUMENT v3.8.0.1
Earnings Per Share (Tables)
 12 Months Ended
Dec. 31, 2017
Earnings Per Share [Abstract]  
Summary of Earnings Per Share, Basic and Diluted
The calculation and reconciliation of basic and diluted earnings per share for the years ended December 31 (in thousands, except per share data) follows:
 
 
 
2017
 
2016
 
2015
Net income
 
$
740,200

 
$
452,385

 
$
362,431

Denominator for basic earnings per share
 
91,129

 
92,597

 
92,023

Dilutive securities
 
2,465

 
2,616

 
2,116

Denominator for diluted earnings per share
 
93,594


95,213


94,139

Basic earnings per share
 
$
8.12

 
$
4.89

 
$
3.94

Diluted earnings per share
 
7.91

 
4.75

 
3.85