Discontinued Operations - Summary of Pretax Profit (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
(Loss) gain on sale of discontinued operations			$ 0	$ 79,602
(Loss) income from discontinued operations, net of tax	$ 0	$ (967)	$ 0	76,697
Discontinued Operations, Disposed of by Sale | GS segment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue		0		27,737
Direct costs		0		19,494
Gross profit		0		8,243
Selling, general and administrative expenses		0		6,842
Depreciation and amortization		0		307
Income from discontinued operations		0		1,094
(Loss) gain on sale of discontinued operations		(402)		79,602
Other expense, net		0		(436)
(Loss) income from discontinued operations, before income taxes		(402)		80,260
Income tax expense		565		3,563
(Loss) income from discontinued operations, net of tax		$ (967)		$ 76,697