Condensed Consolidated Statements of Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue	$ 337,920	$ 511,584	$ 1,138,015	$ 1,541,402
Cost of services	282,749	386,364	908,749	1,149,614
Gross profit	55,171	125,220	229,266	391,788
Selling, general and administrative expenses	53,301	53,964	159,917	166,330
Amortization of intangible assets	7,797	8,627	23,881	25,086
Income (loss) from operations	(5,927)	62,629	45,468	200,372
Interest expense — net	(9,186)	(10,955)	(28,521)	(34,626)
Income (loss) before income tax	(15,113)	51,674	16,947	165,746
Income tax benefit (expense)	8,459	(10,420)	7,490	(33,123)
Net income (loss)	$ (6,654)	$ 41,254	$ 24,437	$ 132,623
Weighted average common shares outstanding:
Cost of services, extensible list			us-gaap:ServiceMember
Common Stock
Earnings (loss) per common share:
Common stock — basic (in dollars per share)	$ (0.11)	$ 0.71	$ 0.41	$ 2.28
Common stock — diluted (in dollars per share)	$ (0.11)	$ 0.69	$ 0.41	$ 2.24
Weighted average common shares outstanding:
Common stock — basic (in shares)	60,196,795	57,935,118	59,253,044	57,820,596
Common stock — diluted (in shares)	60,196,795	59,132,689	60,001,730	58,941,612