Annual report pursuant to Section 13 and 15(d)

Selected Quarterly Data (Unaudited) (Details)

v3.20.1
Selected Quarterly Data (Unaudited) (Details) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2019
Sep. 30, 2019
Jun. 30, 2019
Mar. 31, 2019
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Quarterly Financial Data [Abstract]                      
Revenues $ 195,271 $ 198,326 $ 189,111 $ 169,919 $ 180,996 $ 168,931 $ 170,394 $ 176,897 $ 752,627 $ 697,218 $ 760,113
Costs and operating expenses 180,458 181,111 172,695 158,106 167,911 154,934 156,539 165,304 692,370 644,688 705,788
Operating income 14,813 17,215 16,416 11,813 13,085 15,697 13,855 11,593 60,257 54,230 54,325
Net income $ 9,996 $ 10,527 $ 9,898 $ 6,603 $ 9,243 10,034 $ 8,751 $ 7,052 37,024 35,080 39,096
Gain on sale of contract           $ 1,700     $ 0 $ 1,700 $ 0
Basic earnings per share:                      
Net income (in dollars per share) $ 0.92 $ 0.96 $ 0.90 $ 0.60 $ 0.85 $ 0.92 $ 0.80 $ 0.65 $ 3.38 $ 3.23 $ 3.61
Basic weighted average shares outstanding (in shares) 10,882,000 10,970,000 10,970,000 10,920,000 10,882,000 10,881,000 10,881,000 10,861,000 10,957,750 10,876,201 10,834,562
Diluted earnings per share:                      
Net income (in dollars per share) $ 0.90 $ 0.95 $ 0.89 $ 0.60 $ 0.84 $ 0.92 $ 0.80 $ 0.65 $ 3.35 $ 3.21 $ 3.60
Diluted weighted average shares outstanding (in shares) 11,071,000 11,060,000 11,073,000 10,974,000 10,991,000 10,935,000 10,919,000 10,897,000 11,044,731 10,936,057 10,867,834