Selected Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Selected Quarterly Financial Information [Abstract]
Revenues	$ 170,176	$ 189,433	$ 183,713	$ 166,620	$ 199,793	$ 199,507	$ 165,985	$ 143,105	$ 709,942	$ 708,390	$ 520,894
Gross profit	21,700	22,501	20,744	19,758	19,089	20,893	14,977	9,082	84,703	64,041	16,776
Operating (loss) income	5,052	13,085	4,084	4,365	2,701	6,092	(423)	(6,177)	26,586	2,193	(100,540)
(Loss) income before income taxes	3,982	12,106	3,008	3,100	1,107	4,506	(1,773)	(7,331)	22,196	(3,491)	(106,655)
Net income (loss)	$ 3,666	$ 11,803	$ 2,028	$ 2,723	$ 159	$ 4,039	$ (1,633)	$ (7,924)	$ 20,220	$ (5,359)	$ (94,422)
Earnings Per Share, Basic and Diluted [Abstract]
Basic (USD per share)	$ 0.12	$ 0.39	$ 0.07	$ 0.09	$ 0.01	$ 0.14	$ (0.06)	$ (0.27)	$ 0.67	$ (0.18)	$ (3.31)
Diluted earnings (loss) per share (in dollars per share)	$ 0.12	$ 0.39	$ 0.07	$ 0.09	$ 0.01	$ 0.14	$ (0.06)	$ (0.27)	$ 0.67	$ (0.18)	$ (3.31)