CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue (Note 5)
Revenue	$ 179,917	$ 159,218	$ 138,016
Costs and expenses
Costs and expenses	117,497	106,874	84,954
Selling, general and administrative expenses
Sales and marketing	6,176	5,951	6,014
Research and development	14,243	10,647	8,755
General and administrative	41,704	30,721	29,279
Selling, general and administrative expenses	62,123	47,319	44,048
Operating income	297	5,025	9,014
Other income (expenses)
Gain on redemption of public preferred stock (Note 7)	14,012	0	0
Non-operating (expense) income	(255)	201	12
Interest expense	(7,259)	(7,467)	(7,258)
Income (loss) before income taxes	6,795	(2,241)	1,768
Benefit from (provision for) income taxes (Note 9)	46	104	(31)
Net income (loss)	6,841	(2,137)	1,737
Less: Net income attributable to non-controlling interest (Note 2)	(5,154)	(4,264)	(3,377)
Net income (loss) attributable to Telos Corporation	$ 1,687	$ (6,401)	$ (1,640)
Net earnings (loss) per share attributable to Telos Corporation, basic (in dollars per share)	$ 0.04	$ (0.17)	$ (0.04)
Net earnings (loss) per share attributable to Telos Corporation, diluted (in dollars per share)	$ 0.04	$ (0.17)	$ (0.04)
Weighted-average shares of common stock outstanding, basic (in shares)	41,642,000	37,729,000	36,762,000
Weighted-average shares of common stock outstanding, diluted (in shares)	42,877,000	37,729,000	36,762,000
Services [Member]
Revenue (Note 5)
Revenue	$ 161,180	$ 143,581	$ 120,990
Costs and expenses
Costs and expenses	106,969	98,772	76,857
Products [Member]
Revenue (Note 5)
Revenue	18,737	15,637	17,026
Costs and expenses
Costs and expenses	$ 10,528	$ 8,102	$ 8,097