Summary of Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2018		Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018		Dec. 31, 2017		Sep. 30, 2017		Jun. 30, 2017		Mar. 31, 2017		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Data [Abstract]
Revenue	$ 35,977		$ 34,695		$ 34,943		$ 32,401		$ 35,278		$ 28,243		$ 21,096		$ 23,110		$ 138,016	$ 107,727	$ 134,868
Gross profit	14,465		16,287		12,078		10,232		15,470		9,262		7,391		8,443
Loss before income taxes and non-controlling interest	(1,711)		4,722		450		(1,693)		1,308		(1,755)		(3,011)		(2,807)		1,768	(6,265)	(3,335)
Net (loss) income attributable to Telos Corporation (1)(2)	$ (3,680)	[1],[2]	4,113	[1],[2]	$ (87)	[1],[2]	$ (1,986)	[1],[2]	$ 3,699	[1],[3]	$ (3,044)	[1],[3]	$ (3,389)	[1],[3]	$ (3,099)	[1],[3]	$ (1,640)	$ (5,833)	$ (7,175)
CO&D [Member]
Quarterly Financial Data [Abstract]
Revenue			$ 5,600

[1] Changes in net income are the result of several factors, including seasonality of the government year-end buying season, as well as the nature and timing of other deliverables.

[2] Net income for the third quarter of 2018 included $5.6 million of revenue accruals for multiple contracts as a result of several years of cumulative indirect rate adjustments which did not include direct costs in CO&D's Secure Mobility deliverables.

[3] A tax benefit was recorded due primarily to the remeasurement of our deferred tax assets and liabilities, and the adjustment of valuation allowance related to our hanging credit deferred tax liability in the fourth quarter of 2017, as a result of the Tax Act enacted in December 2017.