Summary of Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ 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 Data [Abstract]
Revenue	$ 46,473		$ 45,531		$ 36,048		$ 31,166		$ 35,977		$ 34,695		$ 34,943		$ 32,401		$ 159,218	$ 138,016	$ 107,727
Gross profit	17,040		16,313		10,015		8,976		14,465		16,287		12,078		10,232
Loss before income taxes and non-controlling interest	(838)		3,708		(1,974)		(3,137)		(1,711)		4,722		450		(1,693)		(2,241)	1,768	(6,265)
Net (loss) income attributable to Telos Corporation (1)(2)	$ (3,480)	[1]	2,233	[1],[2]	$ (1,741)	[1]	$ (3,413)	[1]	$ (3,680)	[1]	$ 4,113	[1],[3]	$ (87)	[1]	$ (1,986)	[1]	$ (6,401)	$ (1,640)	$ (5,833)
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 2019 is attributable to $2.6 million in proprietary software sales which carry lower cost of sales.

[3] 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 Secure Mobility and Network Management/Defense Enterprise Solutions deliverables.