Revision of Interim Financial Statements - Schedule of Error Corrections and Prior Period Adjustments (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended			6 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2021	Sep. 30, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Condensed Consolidated Statement of Operations
Total revenue	$ 68,981	$ 53,644		$ 109,402	$ 178,383	$ 242,433	$ 179,917	$ 159,218
Total costs and expenses						156,404	117,497	106,874
Research and development	4,863				14,250	19,096	14,243	10,647
General and administrative	19,739	29,635	$ 20,076	49,712	69,452	88,742	41,704	30,721
Selling, general and administrative expenses	29,965	40,005	27,963	67,969	97,935	127,493	62,123	47,319
Operating loss	(5,088)	(17,471)		(30,965)	(36,054)	(41,464)	297	5,025
Loss before income taxes	(5,263)	(17,631)		(32,375)	(37,638)	(43,162)	6,795	(2,241)
Net loss	(5,222)	(17,644)		(32,422)	(37,644)	(43,134)	6,841	(2,137)
Net loss attributable to Telos Corporation	$ (5,222)	$ (17,644)		$ (32,422)	$ (37,644)	$ (43,134)	$ 1,687	$ (6,401)
Net loss per share attributable to Telos Corporation
Basic (in dollars per share)	$ (0.08)	$ (0.26)		$ (0.49)	$ (0.57)	$ (0.65)	$ 0.04	$ (0.17)
Diluted (in dollars per share)	$ (0.08)	$ (0.26)		$ (0.49)	$ (0.57)	$ (0.65)	$ 0.04	$ (0.17)
Condensed Consolidated Statement of Cash Flows
Net loss	$ (5,222)	$ (17,644)		$ (32,422)	$ (37,644)	$ (43,134)	$ 6,841	$ (2,137)
Stock-based compensation					47,378	60,231	4	0
Changes in other operating assets and liabilities			(7,148)	(8,723)	(4,362)
Cash used in operating activities			(6,882)	(3,354)	9,637	7,262	(2,104)	11,816
Capitalized software development costs					(6,672)	(9,968)	(6,681)	(2,442)
Cash used in investing activities					(14,242)	(19,094)	(7,461)	(6,532)
Distributions to Telos ID Class B member – non-controlling interest			(2,436)	(2,436)	(2,436)	(2,436)	(2,743)	(2,371)
Cash used in financing activities			(2,757)	33,038	32,695	32,349	108,859	1,395
Condensed Consolidated Statement of Comprehensive Loss
Net loss	(5,222)	(17,644)		(32,422)	(37,644)	(43,134)	6,841	(2,137)
Comprehensive loss attributable to Telos Corporation	(5,235)	(17,639)		(32,449)	(37,684)	(43,205)	1,725	(6,412)
Condensed Consolidated Balance Sheet
Accounts receivable, net	48,674	40,497		40,497	48,674	59,844	30,913
Total current assets	191,215	179,488		179,488	191,215	191,714	144,114
Goodwill	17,922				17,922	17,922	14,916
Intangible assets, net	16,355				16,355	19,199	7,420
Total assets	242,115	221,179		221,179	242,115	246,081	183,817
Accounts payable and other accrued liabilities	34,204				34,204	34,548	20,899
Total current liabilities	53,512				53,512	50,941	38,946
Total liabilities	70,278				70,278	65,827	56,713
Additional paid-in capital	354,300				354,300	367,153	270,800
Accumulated deficit	(182,572)	(176,265)		(176,265)	(182,572)	(186,977)	(143,843)
Total stockholders’ equity	171,837	165,785		165,785	171,837	180,254	127,104	(136,622)	$ (132,103)
Total liabilities and stockholders' equity	242,115	221,179		221,179	242,115	246,081	183,817
Condensed Consolidated Statement of Changes in Stockholders' Equity
Net loss	(5,222)	(17,644)		(32,422)	(37,644)	(43,134)	6,841	(2,137)
Total stockholders’ equity	171,837	165,785		165,785	171,837	180,254	127,104	(136,622)	(132,103)
Accumulated Deficit
Condensed Consolidated Statement of Operations
Net loss						(43,134)	1,687	(6,401)
Condensed Consolidated Statement of Cash Flows
Net loss						(43,134)	1,687	(6,401)
Condensed Consolidated Statement of Comprehensive Loss
Net loss						(43,134)	1,687	(6,401)
Condensed Consolidated Balance Sheet
Total stockholders’ equity	(182,572)	(176,265)		(176,265)	(182,572)	(186,977)	(143,843)	(145,530)	(139,129)
Condensed Consolidated Statement of Changes in Stockholders' Equity
Net loss						(43,134)	1,687	(6,401)
Total stockholders’ equity	(182,572)	(176,265)		(176,265)	(182,572)	(186,977)	(143,843)	(145,530)	(139,129)
Additional Paid–in Capital
Condensed Consolidated Balance Sheet
Total stockholders’ equity	354,300				354,300	367,153	270,800	4,310	4,310
Condensed Consolidated Statement of Changes in Stockholders' Equity
Total stockholders’ equity	354,300				354,300	367,153	270,800	4,310	$ 4,310
Previously Reported
Condensed Consolidated Statement of Operations
Total revenue	70,066	52,559		108,317	178,383
Research and development	5,396				14,783
General and administrative	20,562	28,743	19,964	48,708	69,271
Selling, general and administrative expenses	31,321	39,113	27,851	66,965	98,287
Operating loss	(5,253)	(18,556)		(32,050)	(37,304)
Loss before income taxes	(5,428)	(18,716)		(33,460)	(38,888)
Net loss	(5,387)	(18,729)		(33,507)	(38,894)
Net loss attributable to Telos Corporation	$ (5,387)	$ (18,729)		$ (33,507)	$ (38,894)
Net loss per share attributable to Telos Corporation
Basic (in dollars per share)	$ (0.08)	$ (0.28)		$ (0.51)	$ (0.59)
Diluted (in dollars per share)	$ (0.08)	$ (0.28)		$ (0.51)	$ (0.59)
Condensed Consolidated Statement of Cash Flows
Net loss	$ (5,387)	$ (18,729)		$ (33,507)	$ (38,894)
Stock-based compensation					47,197
Changes in other operating assets and liabilities			(9,584)	(10,074)	(5,900)
Cash used in operating activities			(9,318)	(5,790)	6,668
Capitalized software development costs					(6,139)
Cash used in investing activities					(13,709)
Distributions to Telos ID Class B member – non-controlling interest			0	0	0
Cash used in financing activities			(321)	35,474	35,131
Condensed Consolidated Statement of Comprehensive Loss
Net loss	(5,387)	(18,729)		(33,507)	(38,894)
Comprehensive loss attributable to Telos Corporation	(5,400)	(18,724)		(33,534)	(38,934)
Condensed Consolidated Balance Sheet
Accounts receivable, net	49,759	39,412		39,412	49,759
Total current assets	192,300	178,403		178,403	192,300
Goodwill	16,642				16,642
Intangible assets, net	17,102				17,102
Total assets	242,667	220,094		220,094	242,667
Accounts payable and other accrued liabilities	35,102				35,102
Total current liabilities	54,410				54,410
Total liabilities	71,176				71,176
Additional paid-in capital	354,119				354,119
Accumulated deficit	(182,737)	(177,350)		(177,350)	(182,737)
Total stockholders’ equity	171,491	164,700		164,700	171,491
Total liabilities and stockholders' equity	242,667	220,094		220,094	242,667
Condensed Consolidated Statement of Changes in Stockholders' Equity
Net loss	(5,387)	(18,729)		(33,507)	(38,894)
Total stockholders’ equity	171,491	164,700		164,700	171,491
Previously Reported | Accumulated Deficit
Condensed Consolidated Balance Sheet
Total stockholders’ equity	(182,737)	(177,350)		(177,350)	(182,737)		(143,843)
Condensed Consolidated Statement of Changes in Stockholders' Equity
Total stockholders’ equity	(182,737)	(177,350)		(177,350)	(182,737)		(143,843)
Previously Reported | Additional Paid–in Capital
Condensed Consolidated Balance Sheet
Total stockholders’ equity	354,119				354,119
Condensed Consolidated Statement of Changes in Stockholders' Equity
Total stockholders’ equity	354,119				354,119
Error Correction
Condensed Consolidated Statement of Operations
Total revenue	(1,085)	1,085		1,085	0
Research and development	(533)				(533)
General and administrative	(823)	892	112	1,004	181
Selling, general and administrative expenses	(1,356)	892	112	1,004	(352)
Operating loss	165	1,085		1,085	1,250
Loss before income taxes	165	1,085		1,085	1,250
Net loss	165	1,085		1,085	1,250
Net loss attributable to Telos Corporation	$ 165	$ 1,085		$ 1,085	$ 1,250
Net loss per share attributable to Telos Corporation
Basic (in dollars per share)	$ 0	$ 0.02		$ 0.02	$ 0.02
Diluted (in dollars per share)	$ 0	$ 0.02		$ 0.02	$ 0.02
Condensed Consolidated Statement of Cash Flows
Net loss	$ 165	$ 1,085		$ 1,085	$ 1,250
Stock-based compensation					181
Changes in other operating assets and liabilities			2,436	1,351	1,538
Cash used in operating activities			2,436	2,436	2,969
Capitalized software development costs					(533)
Cash used in investing activities					(533)
Distributions to Telos ID Class B member – non-controlling interest			(2,436)	(2,436)	(2,436)
Cash used in financing activities			(2,436)	(2,436)	(2,436)
Condensed Consolidated Statement of Comprehensive Loss
Net loss	165	1,085		1,085	1,250
Comprehensive loss attributable to Telos Corporation	165	1,085		1,085	1,250
Condensed Consolidated Balance Sheet
Accounts receivable, net	(1,085)	1,085		1,085	(1,085)
Total current assets	(1,085)	1,085		1,085	(1,085)
Goodwill	1,280				1,280
Intangible assets, net	(747)				(747)
Total assets	(552)	1,085		1,085	(552)
Accounts payable and other accrued liabilities	(898)				(898)
Total current liabilities	(898)				(898)
Total liabilities	(898)				(898)
Additional paid-in capital	181				181
Accumulated deficit	165	1,085		1,085	165
Total stockholders’ equity	346	1,085		1,085	346
Total liabilities and stockholders' equity	(552)	1,085		1,085	(552)
Condensed Consolidated Statement of Changes in Stockholders' Equity
Net loss	165	1,085		1,085	1,250
Total stockholders’ equity	346	1,085		1,085	346
Error Correction | Accumulated Deficit
Condensed Consolidated Balance Sheet
Total stockholders’ equity	165	1,085		1,085	165		0
Condensed Consolidated Statement of Changes in Stockholders' Equity
Total stockholders’ equity	165	1,085		1,085	165		0
Error Correction | Additional Paid–in Capital
Condensed Consolidated Balance Sheet
Total stockholders’ equity	181				181
Condensed Consolidated Statement of Changes in Stockholders' Equity
Total stockholders’ equity	181				181
Products and Services
Condensed Consolidated Statement of Operations
Total costs and expenses	44,104	31,110	41,288	72,398	116,502
Products and Services | Previously Reported
Condensed Consolidated Statement of Operations
Total costs and expenses	43,998	32,002	41,400	73,402	117,400
Products and Services | Error Correction
Condensed Consolidated Statement of Operations
Total costs and expenses	106	(892)	(112)	(1,004)	(898)
Services
Condensed Consolidated Statement of Operations
Total revenue	62,955	49,003		101,061	164,016	221,548	161,180	143,581
Total costs and expenses	40,137	28,609	39,490	68,099	108,236	143,357	106,969	98,772
Services | Previously Reported
Condensed Consolidated Statement of Operations
Total revenue	63,690	47,618		99,676	163,366
Total costs and expenses	40,031	29,501	39,602	69,103	109,134
Services | Error Correction
Condensed Consolidated Statement of Operations
Total revenue	(735)	1,385		1,385	650
Total costs and expenses	106	(892)	$ (112)	(1,004)	(898)
Products
Condensed Consolidated Statement of Operations
Total revenue	6,026	4,641		8,341	14,367	20,885	18,737	15,637
Total costs and expenses						$ 13,047	$ 10,528	$ 8,102
Products | Previously Reported
Condensed Consolidated Statement of Operations
Total revenue	6,376	4,941		8,641	15,017
Products | Error Correction
Condensed Consolidated Statement of Operations
Total revenue	$ (350)	$ (300)		$ (300)	$ (650)