Quarterly Financial Information - Summary of Quarterly Financial Information (Detail) - 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 Information Disclosure [Abstract]
Revenues	$ 245,152	$ 247,962	$ 230,982	$ 218,215	$ 237,832	$ 247,287	$ 231,603	$ 223,975	$ 942,311	$ 940,698	$ 920,432
Cost of revenues	191,129	177,198	175,863	189,868	175,588	187,602	183,123	207,713	734,058	754,025	761,901
Gross margin	54,023	70,764	55,119	28,347	62,244	59,685	48,480	16,262	208,253	186,673	158,531
Net (loss) income	$ 11,714	$ 24,971	$ 13,907	$ (2,300)	$ 16,856	$ 19,087	$ 11,240	$ (9,123)	$ 48,292	$ 38,062	$ 25,170
Basic (loss) income per common share	$ 1.57	$ 3.34	$ 1.88	$ (0.31)	$ 2.28	$ 2.59	$ 1.54	$ (1.25)	$ 6.48	$ 5.18	$ 3.46
Diluted (loss) income per common share	$ 1.51	$ 3.24	$ 1.81	$ (0.31)	$ 2.21	$ 2.50	$ 1.46	$ (1.25)	$ 6.27	$ 4.98	$ 3.33