XML 53 R41.htm IDEA: XBRL DOCUMENT v3.8.0.1
Acquisitions and Joint Ventures - Proforma Consolidated Income Statement Information (Detail) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Business Acquisition, Pro Forma Information [Abstract]    
Net Service Revenue $ 1,126,909 $ 1,043,166
Operating income 78,317 73,779
Net income $ 52,300 $ 38,520
Business Acquisition, Pro Forma Earnings Per Share, Diluted $ 2.91 $ 2.18
Business Acquisition, Pro Forma Earnings Per Share, Basic $ 2.95 $ 2.19