Stockholders' Deficit, Option Plans, and Employee Benefit Plan (Details)		1 Months Ended		12 Months Ended
	Nov. 12, 2020	May 31, 2020 shares	May 31, 2017 shares	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) shares	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 shares
General [Abstract]
Common stock, shares authorized (in shares)				250,000,000
Common stock, par value (in dollars per share) | $ / shares				$ 0.001
Preferred stock, shares authorized (in shares)				10,000,000
Preferred stock, par value (in dollars per share) | $ / shares				$ 0.01
Common stock, shares outstanding (in shares)				64,625,071
Preferred stock, shares outstanding (in shares)				0
Reverse stock split	0.794
Conversion of shares (in shares)				1
Restricted Stock Grants [Abstract]
Restricted stock remained subject to vesting (in shares)				59,521
Telos Shared Savings Plan [Abstract]
Shares held in defined contribution employee savings plan (in shares)				2,391,552
Maximum contribution percentage				2.00%
Annual vesting percentage				20.00%
Vesting period of stock options				5 years
Contributions to the Plan | $				$ 998,000	$ 861,000	$ 721,000
Telos ID [Member]
Telos Shared Savings Plan [Abstract]
Maximum contribution percentage				2.00%
Contributions to the Plan | $				$ 179,000	$ 151,000	$ 125,000
Class A Common Stock [Member]
General [Abstract]
Common stock, shares authorized (in shares)					50,000,000
Common stock, shares outstanding (in shares)					35,826,200
Reverse stock split				1.259446
Class B Common Stock [Member]
General [Abstract]
Common stock, shares authorized (in shares)					5,000,000
Common stock, shares outstanding (in shares)					3,204,293
Reverse stock split				1.259446
Restricted Stock [Member]
Restricted Stock Grants [Abstract]
Restricted stock vested on date of grant				25.00%
Restricted stock vest on anniversary of the date of grant				25.00%
Outstanding (in shares)				3,845,030	3,892,646	3,904,550	3,948,199
Forfeited (in shares)				(47,616)	(11,904)	(43,649)
Granted (in shares)		79,361	3,972,007	79,361	0	0