REVISION OF UNAUDITED QUARTERLY FINANCIAL DATA - Revised Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Statement [Abstract]
Total revenue	$ 47,343	$ 63,593	$ 55,791	$ 50,160	$ 64,051	$ 68,981	$ 53,644	$ 55,757	$ 216,887	$ 242,433	$ 179,917
Total cost of sales	29,045	42,648	34,862	31,289	39,902	44,104	31,110	41,288	137,844	156,404	117,497
Gross profit	18,298	20,945	20,929	18,871	24,149	24,877	22,534	14,469	79,043	86,029	62,420
Selling, general and administrative expenses:
Sales and marketing	3,547	3,042	4,741	5,252	5,423	5,363	5,043	3,826	16,582	19,655	6,176
Research and development	3,018	3,981	4,489	5,430	4,845	4,863	5,327	4,061	16,918	19,096	14,243
General and administrative	26,396	22,706	25,735	24,556	19,292	19,739	29,635	20,076	99,393	88,742	41,704
Total selling, general and administrative expenses	32,961	29,729	34,965	35,238	29,560	29,965	40,005	27,963	132,893	127,493	62,123
Operating (loss)/income	(14,663)	(8,784)	(14,036)	(16,367)	(5,411)	(5,088)	(17,471)	(13,494)	(53,850)	(41,464)	297
Other income/(expense)	702	518	118	12	81	20	32	(1,054)	1,350	(921)	(255)
Interest expense	(316)	(181)	(187)	(190)	(194)	(195)	(192)	(196)	(874)	(777)	(7,259)
(Loss)/income before income taxes	(14,277)	(8,447)	(14,105)	(16,545)	(5,524)	(5,263)	(17,631)	(14,744)	(53,374)	(43,162)	6,795
(Provision for)/benefit from income taxes	79	(8)	(54)	(71)	34	41	(13)	(34)	(54)	28	46
Net (loss)/income attributable to Telos Corporation	$ (14,198)	$ (8,455)	$ (14,159)	$ (16,616)	$ (5,490)	$ (5,222)	$ (17,644)	$ (14,778)	$ (53,428)	$ (43,134)	$ 1,687
Net loss per share:
Basic (in dollars per share)	$ (0.21)	$ (0.13)	$ (0.21)	$ (0.25)	$ (0.08)	$ (0.08)	$ (0.26)	$ (0.23)	$ (0.79)	$ (0.65)	$ 0.04
Diluted (in dollars per share)	$ (0.21)	$ (0.13)	$ (0.21)	$ (0.25)	$ (0.08)	$ (0.08)	$ (0.26)	$ (0.23)	$ (0.79)	$ (0.65)	$ 0.04
Services
Income Statement [Abstract]
Total revenue	$ 39,059	$ 55,305	$ 50,270	$ 48,108	$ 57,532	$ 62,955	$ 49,003	$ 52,058	$ 192,742	$ 221,548	$ 161,180
Total cost of sales	23,421	36,746	31,436	29,731	35,121	40,137	28,609	39,490	121,334	143,357	106,969
Products
Income Statement [Abstract]
Total revenue	8,284	8,288	5,521	2,052	6,519	6,026	4,641	3,699	24,145	20,885	18,737
Total cost of sales	$ 5,624	$ 5,902	$ 3,426	$ 1,558	$ 4,781	$ 3,967	$ 2,501	$ 1,798	$ 16,510	$ 13,047	$ 10,528