Annual report pursuant to Section 13 and 15(d)

Quarterly Results of Operations (Unaudited) (Tables)

v3.10.0.1
Quarterly Results of Operations (Unaudited) (Tables)
 12 Months Ended
Dec. 31, 2018
Quarterly Results of Operations (Unaudited) [Abstract]  
Schedule of Quarterly Financial Information [Table Text Block]
The following is a summary of the quarterly results of operations for the years ended December 31, 2018 and 2017: 
 
 
2018
 
 
March 31
 
June 30
 
September 30
 
December 31
Operating revenue
 
$
302,608

 
$
330,343

 
$
331,375

 
$
356,561

Income from operations
 
24,235

 
32,870

 
29,879

 
35,047

Net income
 
17,741

 
24,298

 
22,329

 
27,684

 
 
 
 
 
 
 
 
 
Net income per share:
 
 
 
 
 
 
 
 
   Basic
 
$
0.60

 
$
0.83

 
$
0.76

 
$
0.95

   Diluted
 
$
0.60

 
$
0.82

 
$
0.76

 
$
0.95

 
 
 
 
 
 
 
 
 
 
 
2017
 
 
(As Adjusted)
 
 
March 31
 
June 30
 
September 30
 
December 31
Operating revenue
 
$
262,046

 
$
283,876

 
$
298,289

 
$
325,136

Income from operations
 
23,743

 
29,996

 
27,176

 
27,843

Net income
 
14,581

 
19,666

 
18,328

 
34,681

 
 
 
 
 
 
 
 
 
Net income per share:
 
 
 
 
 
 
 
 
   Basic
 
$
0.48

 
$
0.65

 
$
0.61

 
$
1.17

   Diluted
 
$
0.48

 
$
0.65

 
$
0.61

 
$
1.16