Annual report pursuant to Section 13 and 15(d)

Quarterly Information (Unaudited) (Details)

v3.8.0.1
Quarterly Information (Unaudited) (Details) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]                      
Revenues $ 211,133 $ 204,744 $ 166,665 $ 134,610 $ 174,225 $ 180,598 $ 162,628 $ 133,776 $ 717,152 $ 651,227 $ 630,832
Gross profit 41,459 41,367 35,408 25,924 36,017 38,795 31,856 27,676 144,158 134,344 117,064
Net (loss) income $ 23,811 $ 8,493 $ 5,831 $ (644) $ 3,269 $ 5,715 $ 1,994 $ 1,054 $ 37,491 $ 12,032 $ 844
Net income per share attributable to common shareholders:                      
Basic (in usd per share) $ 0.52 $ 0.19 $ 0.13 $ (0.01) $ 0.07 $ 0.12 $ 0.04 $ 0.02 $ 0.82 $ 0.26 $ 0.02
Diluted (in usd per share) $ 0.52 $ 0.19 $ 0.13 $ (0.01) $ 0.07 $ 0.12 $ 0.04 $ 0.02 $ 0.82 $ 0.26 $ 0.02
Weighted average common shares outstanding:                      
Basic (in shares) 45,537,000 45,524,000 45,463,000 45,514,000 45,811,000 46,361,000 46,719,000 46,742,000 45,509,000 46,409,000 46,494,000
Diluted (in shares) 45,957,000 45,771,000 45,675,000 45,514,000 45,907,000 46,430,000 46,793,000 46,860,000 45,748,000 46,493,000 47,665,000