| Selected Quarterly Data (Unaudited) | 
Selected Quarterly Data (Unaudited) 
  
The following table shows selected quarterly data for 2019 and 2018, in thousands, except earnings per share.
 
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   | 
2019 Quarters  | 
 
   | 
1st  | 
   | 
2nd  | 
   | 
3rd  | 
   | 
4th  | 
 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Revenues  | 
$  | 
169,919  | 
 
  | 
   | 
$  | 
189,111  | 
 
  | 
   | 
$  | 
198,326  | 
 
  | 
   | 
$  | 
195,271  | 
 
  | 
 
Costs and operating expenses  | 
$  | 
158,106  | 
 
  | 
   | 
$  | 
172,695  | 
 
  | 
   | 
$  | 
181,111  | 
 
  | 
   | 
$  | 
180,458  | 
 
  | 
 
Operating income 
  | 
$  | 
11,813  | 
 
  | 
   | 
$  | 
16,416  | 
 
  | 
   | 
$  | 
17,215  | 
 
  | 
   | 
$  | 
14,813  | 
 
  | 
 
Net income 
  | 
$  | 
6,603  | 
 
  | 
   | 
$  | 
9,898  | 
 
  | 
   | 
$  | 
10,527  | 
 
  | 
   | 
$  | 
9,996  | 
 
  | 
 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Basic earnings per share:  | 
   | 
 
  | 
   | 
   | 
 
  | 
   | 
   | 
 
  | 
   | 
   | 
 
  | 
 
Net income 
  | 
$  | 
0.60  | 
 
  | 
   | 
$  | 
0.90  | 
 
  | 
   | 
$  | 
0.96  | 
 
  | 
   | 
$  | 
0.92  | 
 
  | 
 
Basic weighted average shares outstanding  | 
10,920  | 
 
  | 
   | 
10,970  | 
 
  | 
   | 
10,970  | 
 
  | 
   | 
10,882  | 
 
  | 
 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Diluted earnings per share:  | 
   | 
 
  | 
   | 
   | 
 
  | 
   | 
   | 
 
  | 
   | 
   | 
 
  | 
 
Net income 
  | 
$  | 
0.60  | 
 
  | 
   | 
$  | 
0.89  | 
 
  | 
   | 
$  | 
0.95  | 
 
  | 
   | 
$  | 
0.90  | 
 
  | 
 
Diluted weighted average shares outstanding  | 
10,974  | 
 
  | 
   | 
11,073  | 
 
  | 
   | 
11,060  | 
 
  | 
   | 
11,071  | 
 
  | 
 
  
  
  
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   | 
2018 Quarters  | 
 
   | 
1st  | 
   | 
2nd  | 
   | 
3rd  | 
   | 
4th  | 
 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Revenues  | 
$  | 
176,897  | 
 
  | 
   | 
$  | 
170,394  | 
 
  | 
   | 
$  | 
168,931  | 
 
  | 
   | 
$  | 
180,996  | 
 
  | 
 
Costs and operating expenses  | 
$  | 
165,304  | 
 
  | 
   | 
$  | 
156,539  | 
 
  | 
   | 
$  | 
154,934  | 
 
  | 
   | 
$  | 
167,911  | 
 
  | 
 
Operating income  | 
$  | 
11,593  | 
 
  | 
   | 
$  | 
13,855  | 
 
  | 
   | 
$  | 
15,697  | 
 
  | 
   | 
$  | 
13,085  | 
 
  | 
 
Net income (1)
  | 
$  | 
7,052  | 
 
  | 
   | 
$  | 
8,751  | 
 
  | 
   | 
$  | 
10,034  | 
 
  | 
   | 
$  | 
9,243  | 
 
  | 
 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Basic earnings per share:  | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Net income (1)
  | 
$  | 
0.65  | 
 
  | 
   | 
$  | 
0.80  | 
 
  | 
   | 
$  | 
0.92  | 
 
  | 
   | 
$  | 
0.85  | 
 
  | 
 
Basic weighted average shares outstanding  | 
10,861  | 
 
  | 
   | 
10,881  | 
 
  | 
   | 
10,881  | 
 
  | 
   | 
10,882  | 
 
  | 
 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
Diluted earnings per share:  | 
   | 
 
  | 
   | 
   | 
 
  | 
   | 
   | 
 
  | 
   | 
   | 
 
  | 
 
Net income 
  | 
$  | 
0.65  | 
 
  | 
   | 
$  | 
0.80  | 
 
  | 
   | 
$  | 
0.92  | 
 
  | 
   | 
$  | 
0.84  | 
 
  | 
 
Diluted weighted average shares outstanding  | 
10,897  | 
 
  | 
   | 
10,919  | 
 
  | 
   | 
10,935  | 
 
  | 
   | 
10,991  | 
 
  | 
 
  
 
 
  
(1) Operating income for the third quarter of 2018 includes a  $1.7 million gain from the sale of a contract.
 
 
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