Annual report pursuant to Section 13 and 15(d)

Selected Quarterly Financial Data - Schedule of Quarterly Financial Data (Detail)

v3.10.0.1
Selected Quarterly Financial Data - Schedule of Quarterly Financial Data (Detail) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Consolidated Financial Statement Data:                      
Total revenues $ 230,283 $ 210,590 $ 199,402 $ 174,541 $ 202,776 $ 183,341 $ 180,371 $ 153,212      
Cost of services 148,469 132,896 119,869 101,649 131,730 114,803 110,377 89,647 $ 502,883 $ 446,557 $ 444,768
Operating income 32,489 27,384 28,950 23,464 27,403 24,683 24,998 19,048 112,287 96,132 106,501
Net income $ 26,225 $ 20,854 $ 22,167 $ 18,011 $ 8,480 $ 15,475 $ 15,569 $ 12,000 $ 87,257 $ 51,524 $ 64,657
Earnings per share:                      
Basic $ 0.67 $ 0.53 $ 0.57 $ 0.46 $ 0.22 $ 0.40 $ 0.40 $ 0.31 $ 2.23 $ 1.32 $ 1.66
Diluted $ 0.66 $ 0.53 $ 0.56 $ 0.46 $ 0.22 $ 0.39 $ 0.40 $ 0.31 $ 2.22 $ 1.32 $ 1.66